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Mar 21, 2020, 10:36:32 AM3/21/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • Overview

At: http://inquiryintoinquiry.com/2020/03/20/differential-logic-%e2%80%a2-overview/

All,

The previous series of posts on Differential Propositional Calculus

( https://inquiryintoinquiry.com/?s=Differential+Propositional+Calculus )

brought us to the threshold of the subject without quite stepping over,

but I wanted to lay out the necessary ingredients in the most concrete,

intuitive, and visual way possible before taking up the abstract forms.

One of my readers on Facebook told me "venn diagrams are obsolete" and

of course we all know they become unwieldy as our universes of discourse

expand beyond four or five dimensions. Indeed, one of the first lessons

I learned when I set about implementing CSP's graphs and GSB's forms on the

computer was that 2-dimensional representations of logic are a death trap

in numerous conceptual and computational ways. Still, venn diagrams do us

good service in visualizing the relationships among extensional, functional,

and intensional aspects of logic. A facility with those relationships is

critical to the computational applications and statistical generalizations

of logic commonly used in mathematical and empirical practice.

At any rate, intrepid readers will have amped up their visual imaginations

well enough at this point to pick their way through the cactus patch ahead.

The link above or the transcript below outlines my last, best introduction

to Differential Logic, which I'll be working to improve as I serialize it

to my blog.

Part 1 ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1 )

Introduction ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Introduction )

Cactus Language for Propositional Logic (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic )

Differential Expansions of Propositions (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions )

Bird's Eye View ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Bird.27s_Eye_View )

Worm's Eye View ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Worm.27s_Eye_View )

Part 2 ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2 )

Propositional Forms on Two Variables (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables )

Transforms Expanded over Differential Features (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Transforms_Expanded_over_Differential_Features )

Transforms Expanded over Ordinary Features (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Transforms_Expanded_over_Ordinary_Features )

Operational Representation ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Operational_Representation )

Part 3 ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3 )

Development • Field Picture (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Development_.E2.80.A2_Field_Picture )

Proposition and Tacit Extension (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Proposition_and_Tacit_Extension )

Enlargement and Difference Maps (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Enlargement_and_Difference_Maps )

Tangent and Remainder Maps ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Tangent_and_Remainder_Maps )

Least Action Operators ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Least_Action_Operators )

Goal-Oriented Systems ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Goal-Oriented_Systems )

Further Reading ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Further_Reading )

Document History ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Document_History )

Regards,

Jon

inquiry into inquiry: https://inquiryintoinquiry.com/

academia: https://independent.academia.edu/JonAwbrey

oeiswiki: https://www.oeis.org/wiki/User:Jon_Awbrey

facebook page: https://www.facebook.com/JonnyCache

At: http://inquiryintoinquiry.com/2020/03/20/differential-logic-%e2%80%a2-overview/

All,

The previous series of posts on Differential Propositional Calculus

( https://inquiryintoinquiry.com/?s=Differential+Propositional+Calculus )

brought us to the threshold of the subject without quite stepping over,

but I wanted to lay out the necessary ingredients in the most concrete,

intuitive, and visual way possible before taking up the abstract forms.

One of my readers on Facebook told me "venn diagrams are obsolete" and

of course we all know they become unwieldy as our universes of discourse

expand beyond four or five dimensions. Indeed, one of the first lessons

I learned when I set about implementing CSP's graphs and GSB's forms on the

computer was that 2-dimensional representations of logic are a death trap

in numerous conceptual and computational ways. Still, venn diagrams do us

good service in visualizing the relationships among extensional, functional,

and intensional aspects of logic. A facility with those relationships is

critical to the computational applications and statistical generalizations

of logic commonly used in mathematical and empirical practice.

At any rate, intrepid readers will have amped up their visual imaginations

well enough at this point to pick their way through the cactus patch ahead.

The link above or the transcript below outlines my last, best introduction

to Differential Logic, which I'll be working to improve as I serialize it

to my blog.

Part 1 ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1 )

Introduction ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Introduction )

Cactus Language for Propositional Logic (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic )

Differential Expansions of Propositions (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions )

Bird's Eye View ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Bird.27s_Eye_View )

Worm's Eye View ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Worm.27s_Eye_View )

Part 2 ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2 )

Propositional Forms on Two Variables (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables )

Transforms Expanded over Differential Features (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Transforms_Expanded_over_Differential_Features )

Transforms Expanded over Ordinary Features (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Transforms_Expanded_over_Ordinary_Features )

Operational Representation ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Operational_Representation )

Part 3 ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3 )

Development • Field Picture (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Development_.E2.80.A2_Field_Picture )

Proposition and Tacit Extension (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Proposition_and_Tacit_Extension )

Enlargement and Difference Maps (

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Enlargement_and_Difference_Maps )

Tangent and Remainder Maps ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Tangent_and_Remainder_Maps )

Least Action Operators ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Least_Action_Operators )

Goal-Oriented Systems ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Goal-Oriented_Systems )

Further Reading ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3#Further_Reading )

Document History ( https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Document_History )

Regards,

Jon

inquiry into inquiry: https://inquiryintoinquiry.com/

academia: https://independent.academia.edu/JonAwbrey

oeiswiki: https://www.oeis.org/wiki/User:Jon_Awbrey

facebook page: https://www.facebook.com/JonnyCache

Mar 22, 2020, 12:00:20 PM3/22/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 1

At: http://inquiryintoinquiry.com/2020/03/22/differential-logic-%e2%80%a2-1/

Introduction

============

Differential logic is the component of logic whose object is the description of variation — for example, the aspects of

change, difference, distribution, and diversity — in universes of discourse subject to logical description. A

definition that broad naturally incorporates any study of variation by way of mathematical models, but differential

logic is especially charged with the qualitative aspects of variation pervading or preceding quantitative models. To

the extent a logical inquiry makes use of a formal system, its differential component treats the principles governing

the use of a “differential logical calculus”, that is, a formal system with the expressive capacity to describe change

and diversity in logical universes of discourse.

Simple examples of differential logical calculi are furnished by “differential propositional calculi”. A differential

propositional calculus is a propositional calculus extended by a set of terms for describing aspects of change and

difference, for example, processes taking place in a universe of discourse or transformations mapping a source universe

to a target universe. Such a calculus augments ordinary propositional calculus in the same way the differential

calculus of Leibniz and Newton augments the analytic geometry of Descartes.

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/03/22/differential-logic-%e2%80%a2-1/

Introduction

============

Differential logic is the component of logic whose object is the description of variation — for example, the aspects of

change, difference, distribution, and diversity — in universes of discourse subject to logical description. A

definition that broad naturally incorporates any study of variation by way of mathematical models, but differential

logic is especially charged with the qualitative aspects of variation pervading or preceding quantitative models. To

the extent a logical inquiry makes use of a formal system, its differential component treats the principles governing

the use of a “differential logical calculus”, that is, a formal system with the expressive capacity to describe change

and diversity in logical universes of discourse.

Simple examples of differential logical calculi are furnished by “differential propositional calculi”. A differential

propositional calculus is a propositional calculus extended by a set of terms for describing aspects of change and

difference, for example, processes taking place in a universe of discourse or transformations mapping a source universe

to a target universe. Such a calculus augments ordinary propositional calculus in the same way the differential

calculus of Leibniz and Newton augments the analytic geometry of Descartes.

Regards,

Jon

Mar 23, 2020, 3:30:25 PM3/23/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic ??? 2

At: http://inquiryintoinquiry.com/2020/03/23/differential-logic-%e2%80%a2-2/

Cactus Language for Propositional Logic

=======================================

The development of differential logic is facilitated by having a moderately efficient calculus in place at the level of

boolean-valued functions and elementary logical propositions. One very efficient calculus on both conceptual and

computational grounds is based on just two types of logical connectives, both of variable k-ary scope. The syntactic

formulas of this calculus map into a family of graph-theoretic structures called "painted and rooted cacti" which lend

visual representation to the functional structures of propositions and smooth the path to efficient computation.

The first kind of connective takes the form of a parenthesized sequence of propositional expressions, written (e_1, e_2,

..., e_k) and meaning exactly one of the propositions e_1, e_2, ..., e_k is false, in short, their minimal negation is

true. An expression of this form maps into a cactus structure called a "lobe", in this case, "painted" with the colors

e_1, e_2, ..., e_k as shown below.

Lobe Connective

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-ej-lobe-connective.jpg

The second kind of connective is a concatenated sequence of propositional expressions, written e_1 e_2 ... e_k and

meaning all of the propositions e_1, e_2, ..., e_k are true, in short, their logical conjunction is true. An expression

of this form maps into a cactus structure called a "node", in this case, "painted" with the colors e_1, e_2, ..., e_k as

shown below.

Node Connective

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-ej-node-connective.jpg

All other propositional connectives can be obtained through combinations of these two forms. As it happens, the

parenthesized form is sufficient to define the concatenated form, making the latter formally dispensable, but it's

convenient to maintain it as a concise way of expressing more complicated combinations of parenthesized forms. While

working with expressions solely in propositional calculus, it's easiest to use plain parentheses for logical

connectives. In contexts where ordinary parentheses are needed for other purposes an alternate typeface (...) may be

used for the logical operators.

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/03/23/differential-logic-%e2%80%a2-2/

Cactus Language for Propositional Logic

The development of differential logic is facilitated by having a moderately efficient calculus in place at the level of

boolean-valued functions and elementary logical propositions. One very efficient calculus on both conceptual and

computational grounds is based on just two types of logical connectives, both of variable k-ary scope. The syntactic

formulas of this calculus map into a family of graph-theoretic structures called "painted and rooted cacti" which lend

visual representation to the functional structures of propositions and smooth the path to efficient computation.

The first kind of connective takes the form of a parenthesized sequence of propositional expressions, written (e_1, e_2,

..., e_k) and meaning exactly one of the propositions e_1, e_2, ..., e_k is false, in short, their minimal negation is

true. An expression of this form maps into a cactus structure called a "lobe", in this case, "painted" with the colors

e_1, e_2, ..., e_k as shown below.

Lobe Connective

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-ej-lobe-connective.jpg

The second kind of connective is a concatenated sequence of propositional expressions, written e_1 e_2 ... e_k and

meaning all of the propositions e_1, e_2, ..., e_k are true, in short, their logical conjunction is true. An expression

of this form maps into a cactus structure called a "node", in this case, "painted" with the colors e_1, e_2, ..., e_k as

shown below.

Node Connective

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-ej-node-connective.jpg

All other propositional connectives can be obtained through combinations of these two forms. As it happens, the

parenthesized form is sufficient to define the concatenated form, making the latter formally dispensable, but it's

convenient to maintain it as a concise way of expressing more complicated combinations of parenthesized forms. While

working with expressions solely in propositional calculus, it's easiest to use plain parentheses for logical

connectives. In contexts where ordinary parentheses are needed for other purposes an alternate typeface (...) may be

used for the logical operators.

Regards,

Jon

Mar 24, 2020, 2:30:26 PM3/24/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic : 3

At: http://inquiryintoinquiry.com/2020/03/24/differential-logic-%e2%80%a2-3/

Cactus Language for Propositional Logic

=======================================

Table 1 shows the cactus graphs, the corresponding cactus expressions, their logical meanings under the so-called

"existential interpretation", and their translations into conventional notations for a sample of basic propositional forms.

Table 1. Syntax and Semantics of a Calculus for Propositional Logic

https://inquiryintoinquiry.files.wordpress.com/2020/03/syntax-and-semantics-of-a-calculus-for-propositional-logic-2.0.png

The simplest expression for logical truth is the empty word, typically denoted by epsilon or lambda in formal languages,

where it is the identity element for concatenation. To make it visible in context, it may be denoted by the equivalent

expression "(( ))", or, especially if operating in an algebraic context, by a simple "1". Also when working in an

algebraic mode, the plus sign "+" may be used for exclusive disjunction. Thus we have the following translations of

algebraic expressions into cactus expressions.

* a + b = (a, b)

* a + b + c = (a, (b, c)) = ((a, b), c)

It is important to note the last expressions are not equivalent to the 3-place form (a, b, c).

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/03/24/differential-logic-%e2%80%a2-3/

Cactus Language for Propositional Logic

Table 1 shows the cactus graphs, the corresponding cactus expressions, their logical meanings under the so-called

"existential interpretation", and their translations into conventional notations for a sample of basic propositional forms.

Table 1. Syntax and Semantics of a Calculus for Propositional Logic

https://inquiryintoinquiry.files.wordpress.com/2020/03/syntax-and-semantics-of-a-calculus-for-propositional-logic-2.0.png

The simplest expression for logical truth is the empty word, typically denoted by epsilon or lambda in formal languages,

where it is the identity element for concatenation. To make it visible in context, it may be denoted by the equivalent

expression "(( ))", or, especially if operating in an algebraic context, by a simple "1". Also when working in an

algebraic mode, the plus sign "+" may be used for exclusive disjunction. Thus we have the following translations of

algebraic expressions into cactus expressions.

* a + b = (a, b)

* a + b + c = (a, (b, c)) = ((a, b), c)

It is important to note the last expressions are not equivalent to the 3-place form (a, b, c).

Regards,

Jon

Mar 26, 2020, 1:30:26 PM3/26/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic : 4

At: http://inquiryintoinquiry.com/2020/03/26/differential-logic-%e2%80%a2-4/

Differential Expansions of Propositions

=======================================

Bird's Eye View

===============

An efficient calculus for the realm of logic represented by boolean functions and elementary propositions makes it

feasible to compute the finite differences and the differentials of those functions and propositions.

For example, consider a proposition of the form "p and q" graphed as two letters attached to a root node:

Cactus Graph Existential p and q

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-existential-p-and-q.jpg

Written as a string, this is just the concatenation p q.

The proposition pq may be taken as a boolean function f(p, q) having the abstract type f : B x B -> B, where B = {0, 1}

is read in such a way that 0 means false and 1 means true.

Imagine yourself standing in a fixed cell of the corresponding venn diagram, say, the cell where the proposition pq is

true, as shown in the following Figure:

Venn Diagram p and q

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-and-q.jpg

Now ask yourself: What is the value of the proposition pq at a distance of dp and dq from the cell pq where you are

standing?

Don't think about it -- just compute:

Cactus Graph (p,dp)(q,dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdq.jpg

The cactus formula (p, dp)(q, dq) and its corresponding graph arise by substituting p + dp for p and q + dq for q in the

boolean product or logical conjunction pq and writing the result in the two dialects of cactus syntax. This follows

from the fact the boolean sum p + dp is equivalent to the logical operation of exclusive disjunction, which parses to a

cactus graph of the following form:

Cactus Graph (p,dp)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdp.jpg

Next question: What is the difference between the value of the proposition pq over there, at a distance of dp and dq,

and the value of the proposition pq where you are standing, all expressed in the form of a general formula, of course?

Here is the appropriate formulation:

Cactus Graph ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdqpq.jpg

There is one thing I ought to mention at this point: Computed over B, plus and minus are identical operations. This

will make the relation between the differential and the integral parts of the appropriate calculus slightly stranger

than usual, but we will get into that later.

Last question, for now: What is the value of this expression from your current standpoint, that is, evaluated at the

point where pq is true? Well, substituting 1 for p and 1 for q in the graph amounts to erasing the labels p and q, as

shown here:

Cactus Graph (( ,dp)( ,dq), )

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dp-dq-.jpg

And this is equivalent to the following graph:

Cactus Graph ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dpdq.jpg

We have just met with the fact that the differential of the "and" is the "or" of the differentials.

* p and q ---Diff--> dp or dq

Cactus Graph pq Diff ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pq-diff-dpdq.jpg

It will be necessary to develop a more refined analysis of that statement directly, but that is roughly the nub of it.

If the form of the above statement reminds you of De Morgan's rule, it is no accident, as differentiation and negation

turn out to be closely related operations. Indeed, one can find discussions of logical difference calculus in the

Boole-De Morgan correspondence and Peirce also made use of differential operators in a logical context, but the

exploration of these ideas has been hampered by a number of factors, not the least of which has been the lack of a

syntax adequate to handle the complexity of expressions evolving in the process.

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/03/26/differential-logic-%e2%80%a2-4/

Differential Expansions of Propositions

=======================================

Bird's Eye View

===============

An efficient calculus for the realm of logic represented by boolean functions and elementary propositions makes it

feasible to compute the finite differences and the differentials of those functions and propositions.

For example, consider a proposition of the form "p and q" graphed as two letters attached to a root node:

Cactus Graph Existential p and q

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-existential-p-and-q.jpg

Written as a string, this is just the concatenation p q.

The proposition pq may be taken as a boolean function f(p, q) having the abstract type f : B x B -> B, where B = {0, 1}

is read in such a way that 0 means false and 1 means true.

Imagine yourself standing in a fixed cell of the corresponding venn diagram, say, the cell where the proposition pq is

true, as shown in the following Figure:

Venn Diagram p and q

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-and-q.jpg

Now ask yourself: What is the value of the proposition pq at a distance of dp and dq from the cell pq where you are

standing?

Don't think about it -- just compute:

Cactus Graph (p,dp)(q,dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdq.jpg

The cactus formula (p, dp)(q, dq) and its corresponding graph arise by substituting p + dp for p and q + dq for q in the

boolean product or logical conjunction pq and writing the result in the two dialects of cactus syntax. This follows

from the fact the boolean sum p + dp is equivalent to the logical operation of exclusive disjunction, which parses to a

cactus graph of the following form:

Cactus Graph (p,dp)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdp.jpg

Next question: What is the difference between the value of the proposition pq over there, at a distance of dp and dq,

and the value of the proposition pq where you are standing, all expressed in the form of a general formula, of course?

Here is the appropriate formulation:

Cactus Graph ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdqpq.jpg

There is one thing I ought to mention at this point: Computed over B, plus and minus are identical operations. This

will make the relation between the differential and the integral parts of the appropriate calculus slightly stranger

than usual, but we will get into that later.

Last question, for now: What is the value of this expression from your current standpoint, that is, evaluated at the

point where pq is true? Well, substituting 1 for p and 1 for q in the graph amounts to erasing the labels p and q, as

shown here:

Cactus Graph (( ,dp)( ,dq), )

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dp-dq-.jpg

And this is equivalent to the following graph:

Cactus Graph ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dpdq.jpg

We have just met with the fact that the differential of the "and" is the "or" of the differentials.

* p and q ---Diff--> dp or dq

Cactus Graph pq Diff ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pq-diff-dpdq.jpg

It will be necessary to develop a more refined analysis of that statement directly, but that is roughly the nub of it.

If the form of the above statement reminds you of De Morgan's rule, it is no accident, as differentiation and negation

turn out to be closely related operations. Indeed, one can find discussions of logical difference calculus in the

Boole-De Morgan correspondence and Peirce also made use of differential operators in a logical context, but the

exploration of these ideas has been hampered by a number of factors, not the least of which has been the lack of a

syntax adequate to handle the complexity of expressions evolving in the process.

Regards,

Jon

Mar 29, 2020, 12:34:30 PM3/29/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic : 5

At: http://inquiryintoinquiry.com/2020/03/28/differential-logic-%e2%80%a2-5/

Note. I gave it the old college try at transcribing

the following math formulas but I recommend following

the link above for a much more readable copy.

Differential Expansions of Propositions

=======================================

Worm's Eye View

===============

Let's run through the initial example again, keeping an eye on the meanings of the formulas which develop along the way.

We begin with a proposition or a boolean function f(p, q) = pq whose venn diagram and cactus graph are shown below.

Venn Diagram f = pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-f-p-and-q.jpg

Cactus Graph f = pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-f-p-and-q.jpg

A function like this has an abstract type and a concrete type. The abstract type is what we invoke when we write things

like f : B x B -> B or f : B^2 -> B. The concrete type takes into account the qualitative dimensions or the "units" of

the case, which can be explained as follows.

* Let P be the set of values {(p), p} = {not p, p} isomorphic to B = {0, 1}.

* Let Q be the set of values {(q), q} = {not q, q} isomorphic to B = {0, 1}.

Then interpret the usual propositions about p, q as functions of the concrete type f : P x Q -> B.

We are going to consider various operators on these functions. An operator F is a function which takes one function f

into another function Ff.

The first couple of operators we need to consider are logical analogues of two which play a founding role in the

classical finite difference calculus, namely:

* The difference operator Delta, written here as D.

* The enlargement operator Epsilon, written here as E.

These days, E is more often called the "shift operator".

In order to describe the universe in which these operators operate, it is necessary to enlarge the original universe of

discourse. Starting from the initial space X = P x Q, its "(first order) differential extension" EX is constructed

according to the following specifications:

* EX = X x dX

where:

* X = P x Q

* dX = dP x dQ

* dP = {(dp), dp}

* dQ = {(dq), dq}

The interpretations of these new symbols can be diverse, but the easiest option for now is just to say dp means "change

p" and dq means "change q".

Drawing a venn diagram for the differential extension EX = X x dX requires four logical dimensions, P, Q, dP, dQ, but it

is possible to project a suggestion of what the differential features dp and dq are about on the 2-dimensional base

space X = P x Q by drawing arrows that cross the boundaries of the basic circles in the venn diagram for X, reading an

arrow as dp if it crosses the boundary between p and (p) in either direction and reading an arrow as dq if it crosses

the boundary between q and (q) in either direction, as indicated in the following figure.

Venn Diagram p q dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-q-dp-dq.jpg

Propositions are formed on differential variables, or any combination of ordinary logical variables and differential

logical variables, in the same ways propositions are formed on ordinary logical variables alone. For example, the

proposition (dp (dq)) says the same thing as dp => dq, in other words, there is no change in p without a change in q.

Given the proposition f(p, q) over the space X = P x Q, the "(first order) enlargement of f" is the proposition Ef over

the differential extension EX defined by the following formula:

* Ef(p, q, dp, dq)

= f(p + dp, q + dq)

= f(p xor dp, q xor dq)

In the example f(p, q) = pq, the enlargement Ef is computed as follows:

* Ef(p, q, dp, dq)

= (p + dp)(q + dq)

= (p xor dp)(q xor dq)

The corresponding cactus graph is shown below.

Cactus Graph Ef = (p,dp)(q,dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq.jpg

Given the proposition f(p, q) over X = P x Q, the "(first order) difference of f" is the proposition Df over EX defined

by the formula Df = Ef - f, or, written out in full:

* Df(p, q, dp, dq)

= f(p + dp, q + dq) - f(p, q)

= f(p xor dp, q xor dq) xor f(p, q)

In the example f(p, q) = pq, the difference Df is computed as follows:

* Df(p, q, dp, dq)

= (p + dp)(q + dq) - pq

= (p xor dp)(q xor dq) xor pq

The corresponding cactus graph is shown below.

Cactus Graph Df = ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq.jpg

At the end of the previous section we evaluated this first order difference of conjunction Df at a single location in

the universe of discourse, namely, at the point picked out by the singular proposition pq, in terms of coordinates, at

the place where p = 1 and q = 1. This evaluation is written in the form Df|_{pq} or Df|_{(1, 1)}, and we arrived at the

locally applicable law which may be stated and illustrated as follows:

* f(p, q) = pq = p and q => Df|_{pq} = ((dp)(dq)) = dp or dq

Venn Diagram Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-pq-difference-pq-40-pq-1.jpg

Cactus Graph Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pq-difference-pq-40-pq.jpg

The venn diagram shows the analysis of the inclusive disjunction "dp or dq" into the following exclusive disjunction:

* (dp and not dq) xor (dq and not dp) xor (dp and dq)

The resultant differential proposition may be read to say "change p or change q or both". And this can be recognized as

just what you need to do if you happen to find yourself in the center cell and require a complete and detailed

description of ways to escape it.

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/03/28/differential-logic-%e2%80%a2-5/

Note. I gave it the old college try at transcribing

the following math formulas but I recommend following

the link above for a much more readable copy.

Differential Expansions of Propositions

=======================================

===============

Let's run through the initial example again, keeping an eye on the meanings of the formulas which develop along the way.

We begin with a proposition or a boolean function f(p, q) = pq whose venn diagram and cactus graph are shown below.

Venn Diagram f = pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-f-p-and-q.jpg

Cactus Graph f = pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-f-p-and-q.jpg

A function like this has an abstract type and a concrete type. The abstract type is what we invoke when we write things

like f : B x B -> B or f : B^2 -> B. The concrete type takes into account the qualitative dimensions or the "units" of

the case, which can be explained as follows.

* Let P be the set of values {(p), p} = {not p, p} isomorphic to B = {0, 1}.

* Let Q be the set of values {(q), q} = {not q, q} isomorphic to B = {0, 1}.

Then interpret the usual propositions about p, q as functions of the concrete type f : P x Q -> B.

We are going to consider various operators on these functions. An operator F is a function which takes one function f

into another function Ff.

The first couple of operators we need to consider are logical analogues of two which play a founding role in the

classical finite difference calculus, namely:

* The difference operator Delta, written here as D.

* The enlargement operator Epsilon, written here as E.

These days, E is more often called the "shift operator".

In order to describe the universe in which these operators operate, it is necessary to enlarge the original universe of

discourse. Starting from the initial space X = P x Q, its "(first order) differential extension" EX is constructed

according to the following specifications:

* EX = X x dX

where:

* X = P x Q

* dX = dP x dQ

* dP = {(dp), dp}

* dQ = {(dq), dq}

The interpretations of these new symbols can be diverse, but the easiest option for now is just to say dp means "change

p" and dq means "change q".

Drawing a venn diagram for the differential extension EX = X x dX requires four logical dimensions, P, Q, dP, dQ, but it

is possible to project a suggestion of what the differential features dp and dq are about on the 2-dimensional base

space X = P x Q by drawing arrows that cross the boundaries of the basic circles in the venn diagram for X, reading an

arrow as dp if it crosses the boundary between p and (p) in either direction and reading an arrow as dq if it crosses

the boundary between q and (q) in either direction, as indicated in the following figure.

Venn Diagram p q dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-q-dp-dq.jpg

Propositions are formed on differential variables, or any combination of ordinary logical variables and differential

logical variables, in the same ways propositions are formed on ordinary logical variables alone. For example, the

proposition (dp (dq)) says the same thing as dp => dq, in other words, there is no change in p without a change in q.

Given the proposition f(p, q) over the space X = P x Q, the "(first order) enlargement of f" is the proposition Ef over

the differential extension EX defined by the following formula:

* Ef(p, q, dp, dq)

= f(p + dp, q + dq)

= f(p xor dp, q xor dq)

In the example f(p, q) = pq, the enlargement Ef is computed as follows:

* Ef(p, q, dp, dq)

= (p + dp)(q + dq)

= (p xor dp)(q xor dq)

The corresponding cactus graph is shown below.

Cactus Graph Ef = (p,dp)(q,dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq.jpg

Given the proposition f(p, q) over X = P x Q, the "(first order) difference of f" is the proposition Df over EX defined

by the formula Df = Ef - f, or, written out in full:

* Df(p, q, dp, dq)

= f(p + dp, q + dq) - f(p, q)

= f(p xor dp, q xor dq) xor f(p, q)

In the example f(p, q) = pq, the difference Df is computed as follows:

* Df(p, q, dp, dq)

= (p + dp)(q + dq) - pq

= (p xor dp)(q xor dq) xor pq

The corresponding cactus graph is shown below.

Cactus Graph Df = ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq.jpg

At the end of the previous section we evaluated this first order difference of conjunction Df at a single location in

the universe of discourse, namely, at the point picked out by the singular proposition pq, in terms of coordinates, at

the place where p = 1 and q = 1. This evaluation is written in the form Df|_{pq} or Df|_{(1, 1)}, and we arrived at the

locally applicable law which may be stated and illustrated as follows:

* f(p, q) = pq = p and q => Df|_{pq} = ((dp)(dq)) = dp or dq

Venn Diagram Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-pq-difference-pq-40-pq-1.jpg

Cactus Graph Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pq-difference-pq-40-pq.jpg

The venn diagram shows the analysis of the inclusive disjunction "dp or dq" into the following exclusive disjunction:

* (dp and not dq) xor (dq and not dp) xor (dp and dq)

The resultant differential proposition may be read to say "change p or change q or both". And this can be recognized as

just what you need to do if you happen to find yourself in the center cell and require a complete and detailed

description of ways to escape it.

Regards,

Jon

Apr 4, 2020, 11:00:33 AM4/4/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 6

At: http://inquiryintoinquiry.com/2020/04/03/differential-logic-%e2%80%a2-6/

Differential Expansions of Propositions

=======================================

Panoptic View • Difference Maps

===============================

In the last section we computed what is variously called the "difference map", the "difference proposition", or the

"local proposition" Df_x of the proposition f(p, q) = pq at the point x where p = 1 and q = 1.

In the universe of discourse X = P × Q, the four propositions pq, p (q), (p) q, (p)(q) indicating the "cells", or the

smallest distinguished regions of the universe, are called "singular propositions". These serve as an alternative

notation for naming the points (1, 1), (1, 0), (0, 1), (0, 0), respectively.

Thus we can write D}f_x = Df|_x = Df|_(1, 1) = Df|_pq, so long as we know the frame of reference in force.

In the example f(p, q) = pq, the value of the difference proposition Df_x at each of the four points x in X may be

computed in graphical fashion as shown below.

Cactus Graph Df = ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq-1.jpg

Cactus Graph Difference pq @ pq = ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-difference-pq-40-pq-dpdq.jpg

Cactus Graph Difference pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq.jpg

Cactus Graph Difference pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq-1.jpg

Cactus Graph Difference pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dp-dq.jpg

The easy way to visualize the values of these graphical expressions is just to notice the following equivalents.

Cactus Graph Lobe Rule

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-lobe-rule.jpg

Cactus Graph Spike Rule

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-spike-rule.jpg

Laying out the arrows on the augmented venn diagram, one gets a picture of a differential vector field.

Venn Diagram Difference pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/venn-diagram-difference-pq-1.jpg

The Figure shows the points of the extended universe EX = P × Q × dP × dQ indicated by

the difference map Df : EX → B, namely, the following six points or singular propositions.

1. p q dp dq

2. p q dp (dq)

3. p q (dp) dq

4. p (q) (dp) dq

5. (p) q dp (dq)

6. (p)(q) dp dq

The information borne by Df should be clear enough from a survey of these six points — they tell you what you have to do

from each point of X in order to change the value borne by f(p, q), that is, the move you have to make in order to reach

a point where the value of the proposition f(p, q) is different from what it is where you started.

We have been studying the action of the difference operator D on propositions of the form f : P × Q → B, as illustrated

by the example f(p, q) = pq = the conjunction of p and q. The resulting difference map Df is a "(first order)

differential proposition", that is, a proposition of the form Df : P × Q × dP × dQ → B.

The augmented venn diagram shows how the "models" or "satisfying interpretations" of Df distribute over the extended

universe of discourse EX = P × Q × dP × dQ. Abstracting from that picture, the difference map Df can be represented in

the form of a "digraph" or "directed graph", one whose points are labeled with the elements of X = P × Q and whose

arrows are labeled with the elements of dX = dP × dQ, as shown in the following Figure.

Directed Graph Difference pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-difference-pq.jpg

The same 6 points of the extended universe EX = P × Q × dP × dQ given by

the difference map Df : EX → B can be described by the following formula.

Df = p q · ((dp)(dq))

+ p (q) · (dp) dq

+ (p) q · dp (dq)

+ (p)(q) · dp dq

https://en.wikipedia.org/api/rest_v1/media/math/render/svg/347100e1473cdb29b37a928a60eb0661486a1937

Any proposition worth its salt can be analyzed from many different points of view, any one of which has the potential to

reveal previously unsuspected aspects of the proposition’s meaning. We will encounter more and more of these

alternative readings as we go.

At: http://inquiryintoinquiry.com/2020/04/03/differential-logic-%e2%80%a2-6/

Differential Expansions of Propositions

=======================================

===============================

In the last section we computed what is variously called the "difference map", the "difference proposition", or the

"local proposition" Df_x of the proposition f(p, q) = pq at the point x where p = 1 and q = 1.

In the universe of discourse X = P × Q, the four propositions pq, p (q), (p) q, (p)(q) indicating the "cells", or the

smallest distinguished regions of the universe, are called "singular propositions". These serve as an alternative

notation for naming the points (1, 1), (1, 0), (0, 1), (0, 0), respectively.

Thus we can write D}f_x = Df|_x = Df|_(1, 1) = Df|_pq, so long as we know the frame of reference in force.

In the example f(p, q) = pq, the value of the difference proposition Df_x at each of the four points x in X may be

computed in graphical fashion as shown below.

Cactus Graph Df = ((p,dp)(q,dq),pq)

Cactus Graph Difference pq @ pq = ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-difference-pq-40-pq-dpdq.jpg

Cactus Graph Difference pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq.jpg

Cactus Graph Difference pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq-1.jpg

Cactus Graph Difference pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dp-dq.jpg

The easy way to visualize the values of these graphical expressions is just to notice the following equivalents.

Cactus Graph Lobe Rule

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-lobe-rule.jpg

Cactus Graph Spike Rule

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-spike-rule.jpg

Laying out the arrows on the augmented venn diagram, one gets a picture of a differential vector field.

Venn Diagram Difference pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/venn-diagram-difference-pq-1.jpg

The Figure shows the points of the extended universe EX = P × Q × dP × dQ indicated by

the difference map Df : EX → B, namely, the following six points or singular propositions.

1. p q dp dq

2. p q dp (dq)

3. p q (dp) dq

4. p (q) (dp) dq

5. (p) q dp (dq)

6. (p)(q) dp dq

The information borne by Df should be clear enough from a survey of these six points — they tell you what you have to do

from each point of X in order to change the value borne by f(p, q), that is, the move you have to make in order to reach

a point where the value of the proposition f(p, q) is different from what it is where you started.

We have been studying the action of the difference operator D on propositions of the form f : P × Q → B, as illustrated

by the example f(p, q) = pq = the conjunction of p and q. The resulting difference map Df is a "(first order)

differential proposition", that is, a proposition of the form Df : P × Q × dP × dQ → B.

The augmented venn diagram shows how the "models" or "satisfying interpretations" of Df distribute over the extended

universe of discourse EX = P × Q × dP × dQ. Abstracting from that picture, the difference map Df can be represented in

the form of a "digraph" or "directed graph", one whose points are labeled with the elements of X = P × Q and whose

arrows are labeled with the elements of dX = dP × dQ, as shown in the following Figure.

Directed Graph Difference pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-difference-pq.jpg

The same 6 points of the extended universe EX = P × Q × dP × dQ given by

the difference map Df : EX → B can be described by the following formula.

Df = p q · ((dp)(dq))

+ p (q) · (dp) dq

+ (p) q · dp (dq)

+ (p)(q) · dp dq

https://en.wikipedia.org/api/rest_v1/media/math/render/svg/347100e1473cdb29b37a928a60eb0661486a1937

Any proposition worth its salt can be analyzed from many different points of view, any one of which has the potential to

reveal previously unsuspected aspects of the proposition’s meaning. We will encounter more and more of these

alternative readings as we go.

Apr 6, 2020, 10:24:19 AM4/6/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 7

At: http://inquiryintoinquiry.com/2020/04/05/differential-logic-%e2%80%a2-7/

Differential Expansions of Propositions

=======================================

Panoptic View • Enlargement Maps

================================

The "enlargement" or "shift" operator E exhibits a wealth of interesting and useful properties in its own right, so it

pays to examine a few of the more salient features playing out on the surface of our initial example, f(p, q) = pq.

A suitably generic definition of the extended universe of discourse is afforded by the following set-up.

* Let X = X_1 × ... × X_k.

* Let dX = dX_1 × ... × dX_k.

* Then EX = X × dX

= X_1 × ... × X_k × dX_1 × ... × dX_k

For a proposition of the form f : X_1 × ... × X_k → B, the "(first order) enlargement" of f is the proposition Ef : EX →

B defined by the following equation.

* Ef(x_1, ..., x_k, dx_1, ..., dx_k)

= f(x_1 + dx_1, ..., x_k + dx_k)

= f(x_1 xor dx_1, ..., x_k xor dx_k)

The "differential variables" dx_j are boolean variables of the same type as the ordinary variables x_j. Although it is

conventional to distinguish the (first order) differential variables with the operational prefix "d" this way of

notating differential variables is entirely optional. It is their existence in particular relations to the initial

variables, not their names, which defines them as differential variables.

In the example of logical conjunction, f(p, q) = pq, the enlargement Ef is formulated as follows.

* Ef(p, q, dp, dq) = (p + dp)(q + dq) = (p xor dp)(q xor dq)

Given that this expression uses nothing more than the boolean ring operations of addition and multiplication, it is

permissible to “multiply things out” in the usual manner to arrive at the following result.

* Ef(p, q, dp, dq) = p·q + p·dq + q·dp + dp·dq

To understand what the enlarged or shifted proposition means in logical terms, it serves to go back and analyze the

above expression for Ef in the same way we did for Df. To that end, the value of Ef_x at each x in X may be computed in

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq-1.jpg

Cactus Graph Enlargement pq @ pq = (dp)(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq.jpg

Cactus Graph Enlargement pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-1.jpg

Cactus Graph Enlargement pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-2.jpg

Cactus Graph Enlargement pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dp-dq.jpg

Collating the data of this analysis yields a boolean expansion or disjunctive normal form (DNF) equivalent to the

enlarged proposition Ef.

* Ef = p q · Ef @ p q

+ p (q) · Ef @ p (q)

+ (p) q · Ef @ (p) q}

+ (p)(q) · Ef @ (p)(q)

Here is a summary of the result, illustrated by means of a digraph picture, where the “no change” element ¬dp∧¬dq is

drawn as a loop at the point pq.

Directed Graph Enlargement pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-enlargement-pq.jpg

https://en.wikipedia.org/api/rest_v1/media/math/render/svg/6b32eadd66a62c7cefc8c31d52f46708d68f3adc

We may understand the enlarged proposition Ef as telling us all the ways of reaching a model of the proposition f from

the points of the universe X.

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/04/05/differential-logic-%e2%80%a2-7/

Differential Expansions of Propositions

=======================================

================================

The "enlargement" or "shift" operator E exhibits a wealth of interesting and useful properties in its own right, so it

pays to examine a few of the more salient features playing out on the surface of our initial example, f(p, q) = pq.

A suitably generic definition of the extended universe of discourse is afforded by the following set-up.

* Let X = X_1 × ... × X_k.

* Let dX = dX_1 × ... × dX_k.

* Then EX = X × dX

= X_1 × ... × X_k × dX_1 × ... × dX_k

For a proposition of the form f : X_1 × ... × X_k → B, the "(first order) enlargement" of f is the proposition Ef : EX →

B defined by the following equation.

* Ef(x_1, ..., x_k, dx_1, ..., dx_k)

= f(x_1 + dx_1, ..., x_k + dx_k)

= f(x_1 xor dx_1, ..., x_k xor dx_k)

The "differential variables" dx_j are boolean variables of the same type as the ordinary variables x_j. Although it is

conventional to distinguish the (first order) differential variables with the operational prefix "d" this way of

notating differential variables is entirely optional. It is their existence in particular relations to the initial

variables, not their names, which defines them as differential variables.

In the example of logical conjunction, f(p, q) = pq, the enlargement Ef is formulated as follows.

* Ef(p, q, dp, dq) = (p + dp)(q + dq) = (p xor dp)(q xor dq)

permissible to “multiply things out” in the usual manner to arrive at the following result.

* Ef(p, q, dp, dq) = p·q + p·dq + q·dp + dp·dq

To understand what the enlarged or shifted proposition means in logical terms, it serves to go back and analyze the

above expression for Ef in the same way we did for Df. To that end, the value of Ef_x at each x in X may be computed in

graphical fashion as shown below.

Cactus Graph Ef = (p,dp)(q,dq)
https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq-1.jpg

Cactus Graph Enlargement pq @ pq = (dp)(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq.jpg

Cactus Graph Enlargement pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-1.jpg

Cactus Graph Enlargement pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-2.jpg

Cactus Graph Enlargement pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dp-dq.jpg

Collating the data of this analysis yields a boolean expansion or disjunctive normal form (DNF) equivalent to the

enlarged proposition Ef.

* Ef = p q · Ef @ p q

+ p (q) · Ef @ p (q)

+ (p) q · Ef @ (p) q}

+ (p)(q) · Ef @ (p)(q)

Here is a summary of the result, illustrated by means of a digraph picture, where the “no change” element ¬dp∧¬dq is

drawn as a loop at the point pq.

Directed Graph Enlargement pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-enlargement-pq.jpg

https://en.wikipedia.org/api/rest_v1/media/math/render/svg/6b32eadd66a62c7cefc8c31d52f46708d68f3adc

We may understand the enlarged proposition Ef as telling us all the ways of reaching a model of the proposition f from

the points of the universe X.

Regards,

Jon

Apr 8, 2020, 10:13:14 AM4/8/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 8

At: http://inquiryintoinquiry.com/2020/04/08/differential-logic-%e2%80%a2-8/

Propositional Forms on Two Variables

====================================

To broaden our experience with simple examples, let's examine the sixteen functions of concrete type P × Q → B and

abstract type B × B → B. The time we took contemplating logical conjunction from a variety of differential angles will

pay dividends as we study its kindred family of forms in the same lights.

Table A1 arranges the propositional forms on two variables in a convenient order, giving equivalent expressions for each

boolean function in several systems of notation.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/04/08/differential-logic-%e2%80%a2-8/

Propositional Forms on Two Variables

To broaden our experience with simple examples, let's examine the sixteen functions of concrete type P × Q → B and

abstract type B × B → B. The time we took contemplating logical conjunction from a variety of differential angles will

pay dividends as we study its kindred family of forms in the same lights.

Table A1 arranges the propositional forms on two variables in a convenient order, giving equivalent expressions for each

boolean function in several systems of notation.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Regards,

Jon

Apr 8, 2020, 4:38:17 PM4/8/20

to structura...@googlegroups.com, Cybernetic Communications, Ontolog Forum, Peirce List, SysSciWG

Jon:

I like the chart, things are starting to make a little more sense to me.

Further, I read your paper," An Architecture for Inquiry
: Building Computer Platforms for Discovery" from Research Gate.

The examples in the paper help to add additional context.

Take care, be good to yourself and have fun,

Joe

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To view this discussion on the web visit https://groups.google.com/d/msgid/structural-modeling/a5022d2b-8ca0-d75d-7947-3cffdd94de26%40att.net.

Joe Simpson

# “Reasonable people adapt themselves to the world.

# Unreasonable people attempt to adapt the world to themselves.

# All progress, therefore, depends on unreasonable people.”

- George Bernard Shaw
- Git Hub link:
- Research Gate link:
- YouTube Channel
- Web Site:

Apr 9, 2020, 10:54:14 AM4/9/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 1

At: http://inquiryintoinquiry.com/2020/04/09/differential-logic-%e2%80%a2-discussion-1/

Re: Joseph Simpson

At: https://groups.google.com/d/msg/structural-modeling/xB5tRt4mcEM/IfaF8YlLBgAJ

Thanks, Joe, glad you liked the table, I've got a million of 'em! I'll be setting another mess of tables directly as we

continue studying the effects of differential operators on families of propositional forms.

For anyone wondering, "Where's the Peirce?" — he is the Atlas on whose shoulders the whole world of differential logic

turns. The elegant efficiency of Peirce's logical graphs, augmented by Spencer Brown and extended to cactus graphs,

made it feasible for the first time to take on the extra complexities of differential propositional calculus. So that

theme is a constant throughout the development of differential logic.

Hope you and yours are safe and sound,

Jon

On 4/8/2020 4:38 PM, joseph simpson wrote:

> Jon:

>

> I like the chart, things are starting to make a little more sense to me.

>

> Further, I read your paper, "An Architecture for Inquiry :

> Building Computer Platforms for Discovery" from Research Gate.

[ https://www.academia.edu/1270327/An_Architecture_for_Inquiry_Building_Computer_Platforms_for_Discovery ]

At: http://inquiryintoinquiry.com/2020/04/09/differential-logic-%e2%80%a2-discussion-1/

Re: Joseph Simpson

At: https://groups.google.com/d/msg/structural-modeling/xB5tRt4mcEM/IfaF8YlLBgAJ

Thanks, Joe, glad you liked the table, I've got a million of 'em! I'll be setting another mess of tables directly as we

continue studying the effects of differential operators on families of propositional forms.

For anyone wondering, "Where's the Peirce?" — he is the Atlas on whose shoulders the whole world of differential logic

turns. The elegant efficiency of Peirce's logical graphs, augmented by Spencer Brown and extended to cactus graphs,

made it feasible for the first time to take on the extra complexities of differential propositional calculus. So that

theme is a constant throughout the development of differential logic.

Hope you and yours are safe and sound,

Jon

On 4/8/2020 4:38 PM, joseph simpson wrote:

> Jon:

>

> I like the chart, things are starting to make a little more sense to me.

>

> Further, I read your paper, "An Architecture for Inquiry :

> Building Computer Platforms for Discovery" from Research Gate.

Apr 11, 2020, 10:13:10 AM4/11/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 9

At: http://inquiryintoinquiry.com/2020/04/11/differential-logic-%e2%80%a2-9/

Propositional Forms on Two Variables

====================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables

Table A2 arranges the propositional forms on two variables according to another plan, sorting propositions with similar

shapes into seven subclasses. Thereby hangs many a tale, to be told in time.

Table A2. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/04/11/differential-logic-%e2%80%a2-9/

Propositional Forms on Two Variables

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables

Table A2 arranges the propositional forms on two variables according to another plan, sorting propositions with similar

shapes into seven subclasses. Thereby hangs many a tale, to be told in time.

Table A2. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

Regards,

Jon

Apr 13, 2020, 9:30:29 PM4/13/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

On 4/9/2020 11:02 AM, Edwina Taborsky wrote:

>

> Yes - I think Peirce and Spencer Brown work very well together.

>

> Thanks for all your work.

>

> Edwina

Thanks, Edwina. I first encountered Peirce's Collected Papers

sometime during my freshman year in one of the quieter corners

of the Michigan State Math Library where I used to hide out to

study and shortly after a friend showed me the description of

Spencer Brown's "Laws of Form" in the 1st Whole Earth Catalog

and I sent off for it right away. I would spend the next ten

years trying to figure out what either one of them was saying.

In my view, Spencer Brown penetrated to the deepest strata of

Peirce's core ideas about logic, recognizing its operational

aspect and relational power in a way we've seldom seen since.

Not too coincidentally, those aspects and powers were a big

part of what I wrote my Senior Thesis on at the end of my

undergrad years.

Regards,

Jon

>

> Yes - I think Peirce and Spencer Brown work very well together.

>

> Thanks for all your work.

>

> Edwina

Thanks, Edwina. I first encountered Peirce's Collected Papers

sometime during my freshman year in one of the quieter corners

of the Michigan State Math Library where I used to hide out to

study and shortly after a friend showed me the description of

Spencer Brown's "Laws of Form" in the 1st Whole Earth Catalog

and I sent off for it right away. I would spend the next ten

years trying to figure out what either one of them was saying.

In my view, Spencer Brown penetrated to the deepest strata of

Peirce's core ideas about logic, recognizing its operational

aspect and relational power in a way we've seldom seen since.

Not too coincidentally, those aspects and powers were a big

part of what I wrote my Senior Thesis on at the end of my

undergrad years.

Regards,

Jon

Apr 26, 2020, 7:30:39 AM4/26/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 10

At: http://inquiryintoinquiry.com/2020/04/25/differential-logic-%e2%80%a2-10/

It’s been a while, so let’s review …

Tables A1 and A2 showed two ways of organizing the sixteen boolean functions or propositional forms on two variables, as

expressed in several notations. For ease of reference, here are fresh copies of those tables.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Table A2. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

We took as our first example the boolean function f_8(p, q) = pq corresponding to the logical conjunction p ∧ q and

examined how the differential operators E and D act on f_8. Each differential operator takes a boolean function of two

variables f_8(p, q) and gives back a boolean function of four variables, Ef_8(p, q, dp, dq) or Df_8(p, q, dp, dq),

respectively.

In the next several posts we’ll extend our scope to the full set of boolean functions on two variables and examine how

the differential operators E and D act on that set. There being some advantage to singling out the enlargement or shift

operator E in its own right, we’ll begin by computing Ef for each function f in the above tables.

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/04/25/differential-logic-%e2%80%a2-10/

It’s been a while, so let’s review …

Tables A1 and A2 showed two ways of organizing the sixteen boolean functions or propositional forms on two variables, as

expressed in several notations. For ease of reference, here are fresh copies of those tables.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Table A2. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

We took as our first example the boolean function f_8(p, q) = pq corresponding to the logical conjunction p ∧ q and

examined how the differential operators E and D act on f_8. Each differential operator takes a boolean function of two

variables f_8(p, q) and gives back a boolean function of four variables, Ef_8(p, q, dp, dq) or Df_8(p, q, dp, dq),

respectively.

In the next several posts we’ll extend our scope to the full set of boolean functions on two variables and examine how

the differential operators E and D act on that set. There being some advantage to singling out the enlargement or shift

operator E in its own right, we’ll begin by computing Ef for each function f in the above tables.

Regards,

Jon

Jun 17, 2020, 2:45:28 PM6/17/20

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 3

At: http://inquiryintoinquiry.com/2020/06/17/differential-logic-%e2%80%a2-discussion-3/

Re: R.J. Lipton

https://rjlipton.wordpress.com/about-me/

Re: P<NP

https://rjlipton.wordpress.com/2020/06/16/pnp/

Instead of boolean circuit complexity I would look at logical graph complexity, where those logical graphs are

constructed from minimal negation operators.

Physics once had a frame problem (complexity of dynamic updating) long before AI did but physics learned to reduce

complexity through the use of differential equations and group symmetries (combined in Lie groups).

One of the promising features of minimal negation operators is their relationship to differential operators. So I've

been looking into that. Here’s a link, a bit in medias res, but what I've got for now.

• Differential Logic • Cactus Language

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic

Resources

=========

• Logical Graphs

https://oeis.org/wiki/Logical_Graphs

• Minimal Negation Operators

https://oeis.org/wiki/Minimal_negation_operator

• Survey of Animated Logical Graphs

https://inquiryintoinquiry.com/2019/05/22/survey-of-animated-logical-graphs-%e2%80%a2-2/

• Survey of Differential Logic

https://inquiryintoinquiry.com/2020/02/08/survey-of-differential-logic-%e2%80%a2-2/

• Survey of Theme One Program

https://inquiryintoinquiry.com/2018/02/25/survey-of-theme-one-program-%e2%80%a2-2/

Regards,

Jon

At: http://inquiryintoinquiry.com/2020/06/17/differential-logic-%e2%80%a2-discussion-3/

Re: R.J. Lipton

https://rjlipton.wordpress.com/about-me/

Re: P<NP

https://rjlipton.wordpress.com/2020/06/16/pnp/

Instead of boolean circuit complexity I would look at logical graph complexity, where those logical graphs are

constructed from minimal negation operators.

Physics once had a frame problem (complexity of dynamic updating) long before AI did but physics learned to reduce

complexity through the use of differential equations and group symmetries (combined in Lie groups).

One of the promising features of minimal negation operators is their relationship to differential operators. So I've

been looking into that. Here’s a link, a bit in medias res, but what I've got for now.

• Differential Logic • Cactus Language

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic

Resources

=========

• Logical Graphs

https://oeis.org/wiki/Logical_Graphs

• Minimal Negation Operators

https://oeis.org/wiki/Minimal_negation_operator

• Survey of Animated Logical Graphs

https://inquiryintoinquiry.com/2019/05/22/survey-of-animated-logical-graphs-%e2%80%a2-2/

• Survey of Differential Logic

https://inquiryintoinquiry.com/2020/02/08/survey-of-differential-logic-%e2%80%a2-2/

• Survey of Theme One Program

https://inquiryintoinquiry.com/2018/02/25/survey-of-theme-one-program-%e2%80%a2-2/

Regards,

Jon

Jun 15, 2021, 10:54:36 AMJun 15

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG, Laws of Form

Cf: Differential Logic • Overview

https://inquiryintoinquiry.com/2020/03/20/differential-logic-overview/

LoF Group,

| The following series of posts on Differential Logic were

| shared to my other lists back in 2020 when the LoF Group

| was experiencing its bout of “listlessness”. I'll copy

| them here partly by way of general background and also

| for context in answering Lyle's last set of questions.

The previous series of posts on Differential Propositional Calculus

( https://inquiryintoinquiry.com/?s=Differential+Propositional+Calculus )

brought us to the threshold of the subject without quite stepping over,

but I wanted to lay out the necessary ingredients in the most concrete,

intuitive, and visual way possible before taking up the abstract forms.

One of my readers on Facebook told me “venn diagrams are obsolete” and

of course we all know they become unwieldy as our universes of discourse

expand beyond four or five dimensions. Indeed, one of the first lessons

I learned when I set about implementing CSP's graphs and GSB's forms on the

computer was that 2-dimensional representations of logic are a death trap

in numerous conceptual and computational ways. Still, venn diagrams do us

good service in visualizing the relationships among extensional, functional,

and intensional aspects of logic. A facility with those relationships is

critical to the computational applications and statistical generalizations

of logic commonly used in mathematical and empirical practice.

At any rate, intrepid readers will have amped up their visual imaginations

well enough at this point to pick their way through the cactus patch ahead.

The link above or the transcript below outlines my last, best introduction

to Differential Logic, which I'll be working to improve as I serialize it

to my blog.

Resource

========

Differential Logic

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Overview

https://inquiryintoinquiry.com/2020/03/20/differential-logic-overview/

LoF Group,

| The following series of posts on Differential Logic were

| shared to my other lists back in 2020 when the LoF Group

| was experiencing its bout of “listlessness”. I'll copy

| them here partly by way of general background and also

| for context in answering Lyle's last set of questions.

The previous series of posts on Differential Propositional Calculus

( https://inquiryintoinquiry.com/?s=Differential+Propositional+Calculus )

brought us to the threshold of the subject without quite stepping over,

but I wanted to lay out the necessary ingredients in the most concrete,

intuitive, and visual way possible before taking up the abstract forms.

One of my readers on Facebook told me “venn diagrams are obsolete” and

of course we all know they become unwieldy as our universes of discourse

expand beyond four or five dimensions. Indeed, one of the first lessons

I learned when I set about implementing CSP's graphs and GSB's forms on the

computer was that 2-dimensional representations of logic are a death trap

in numerous conceptual and computational ways. Still, venn diagrams do us

good service in visualizing the relationships among extensional, functional,

and intensional aspects of logic. A facility with those relationships is

critical to the computational applications and statistical generalizations

of logic commonly used in mathematical and empirical practice.

At any rate, intrepid readers will have amped up their visual imaginations

well enough at this point to pick their way through the cactus patch ahead.

The link above or the transcript below outlines my last, best introduction

to Differential Logic, which I'll be working to improve as I serialize it

to my blog.

========

Differential Logic

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Overview

Jun 15, 2021, 2:36:19 PMJun 15

to Cybernetic Communications, Laws of Form, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 1

https://inquiryintoinquiry.com/2020/03/22/differential-logic-1/

Introduction

============

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Introduction

Differential logic is the component of logic whose object is

the description of variation — for example, the aspects of change,

difference, distribution, and diversity — in universes of discourse

subject to logical description. A definition that broad naturally

incorporates any study of variation by way of mathematical models,

but differential logic is especially charged with the qualitative

aspects of variation pervading or preceding quantitative models.

To the extent a logical inquiry makes use of a formal system,

its differential component treats the principles governing the

use of a differential logical calculus, that is, a formal system

[1] https://oeis.org/wiki/Universe_of_discourse

[2] https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Overview

[3] https://oeis.org/wiki/Propositional_calculus

https://inquiryintoinquiry.com/2020/03/22/differential-logic-1/

Introduction

============

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Introduction

Differential logic is the component of logic whose object is

the description of variation — for example, the aspects of change,

difference, distribution, and diversity — in universes of discourse

subject to logical description. A definition that broad naturally

incorporates any study of variation by way of mathematical models,

but differential logic is especially charged with the qualitative

aspects of variation pervading or preceding quantitative models.

To the extent a logical inquiry makes use of a formal system,

its differential component treats the principles governing the

with the expressive capacity to describe change and diversity in

logical universes of discourse.

Simple examples of differential logical calculi are furnished by

differential propositional calculi. A differential propositional
logical universes of discourse.

Simple examples of differential logical calculi are furnished by

calculus is a propositional calculus extended by a set of terms for

describing aspects of change and difference, for example, processes

taking place in a universe of discourse or transformations mapping

a source universe to a target universe. Such a calculus augments

ordinary propositional calculus in the same way the differential

calculus of Leibniz and Newton augments the analytic geometry

of Descartes.

References
describing aspects of change and difference, for example, processes

taking place in a universe of discourse or transformations mapping

a source universe to a target universe. Such a calculus augments

ordinary propositional calculus in the same way the differential

calculus of Leibniz and Newton augments the analytic geometry

of Descartes.

[1] https://oeis.org/wiki/Universe_of_discourse

[2] https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Overview

[3] https://oeis.org/wiki/Propositional_calculus

Jun 15, 2021, 4:56:25 PMJun 15

to Cybernetic Communications, Laws of Form, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 2

https://inquiryintoinquiry.com/2020/03/23/differential-logic-2/

Cactus Language for Propositional Logic

=======================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic

The development of differential logic is facilitated by having a moderately

efficient calculus in place at the level of boolean-valued functions and

elementary logical propositions. One very efficient calculus on both

conceptual and computational grounds is based on just two types of

logical connectives, both of variable k-ary scope. The syntactic

formulas of this calculus map into a family of graph-theoretic

structures called “painted and rooted cacti” which lend visual

representation to the functional structures of propositions

and smooth the path to efficient computation.

The first kind of connective takes the form of a parenthesized sequence

of propositional expressions, written (e₁, e₂, …, eₖ) and meaning exactly

one of the propositions e₁, e₂, …, eₖ is false, in short, their “minimal

shown below.

Figure 1. Lobe Connective

[1] https://oeis.org/wiki/Boolean-valued_function

[2] https://oeis.org/wiki/Minimal_negation_operator

[3] https://oeis.org/wiki/Logical_conjunction

https://inquiryintoinquiry.com/2020/03/23/differential-logic-2/

Cactus Language for Propositional Logic

=======================================

The development of differential logic is facilitated by having a moderately

efficient calculus in place at the level of boolean-valued functions and

elementary logical propositions. One very efficient calculus on both

conceptual and computational grounds is based on just two types of

logical connectives, both of variable k-ary scope. The syntactic

formulas of this calculus map into a family of graph-theoretic

structures called “painted and rooted cacti” which lend visual

representation to the functional structures of propositions

and smooth the path to efficient computation.

The first kind of connective takes the form of a parenthesized sequence

one of the propositions e₁, e₂, …, eₖ is false, in short, their “minimal

negation” is true. An expression of this form maps into a cactus structure

called a “lobe”, in this case, “painted” with the colors e₁, e₂, …, eₖ as
shown below.

Figure 1. Lobe Connective

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-ej-lobe-connective.jpg

The second kind of connective is a concatenated sequence of propositional expressions,

written e₁ e₂ … eₖ and meaning all of the propositions e₁, e₂, …, eₖ are true, in short,
The second kind of connective is a concatenated sequence of propositional expressions,

their logical conjunction is true. An expression of this form maps into a cactus structure

called a “node”, in this case, “painted” with the colors e_1, e_2, ..., e_k as shown below.

Figure 2. Node Connective
called a “node”, in this case, “painted” with the colors e_1, e_2, ..., e_k as shown below.

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-ej-node-connective.jpg

All other propositional connectives can be obtained through combinations

of these two forms. As it happens, the parenthesized form is sufficient

to define the concatenated form, making the latter formally dispensable,

but it's convenient to maintain it as a concise way of expressing more

complicated combinations of parenthesized forms. While working with

expressions solely in propositional calculus, it's easiest to use

plain parentheses for logical connectives. In contexts where

ordinary parentheses are needed for other purposes an alternate

typeface (...) may be used for the logical operators.

References
All other propositional connectives can be obtained through combinations

of these two forms. As it happens, the parenthesized form is sufficient

to define the concatenated form, making the latter formally dispensable,

but it's convenient to maintain it as a concise way of expressing more

complicated combinations of parenthesized forms. While working with

expressions solely in propositional calculus, it's easiest to use

plain parentheses for logical connectives. In contexts where

ordinary parentheses are needed for other purposes an alternate

typeface (...) may be used for the logical operators.

[1] https://oeis.org/wiki/Boolean-valued_function

[2] https://oeis.org/wiki/Minimal_negation_operator

[3] https://oeis.org/wiki/Logical_conjunction

Jun 16, 2021, 11:10:47 AMJun 16

to Cybernetic Communications, Laws of Form, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG

Cf: Differential Logic • 3

https://inquiryintoinquiry.com/2020/03/24/differential-logic-3/

Cactus Language for Propositional Logic

=======================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic

The simplest expression for logical truth is the empty word,

typically denoted by ε or λ in formal languages, where it is

• a + b + c = (a, (b, c)) = ((a, b), c)

https://inquiryintoinquiry.com/2020/03/24/differential-logic-3/

Cactus Language for Propositional Logic

=======================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Cactus_Language_for_Propositional_Logic

Table 1 shows the cactus graphs, the corresponding cactus expressions,

their logical meanings under the so-called “existential interpretation”,

and their translations into conventional notations for a sample of

basic propositional forms.

Table 1. Syntax and Semantics of a Calculus for Propositional Logic

https://inquiryintoinquiry.files.wordpress.com/2021/03/syntax-and-semantics-of-a-calculus-for-propositional-logic-3.0.png
their logical meanings under the so-called “existential interpretation”,

and their translations into conventional notations for a sample of

basic propositional forms.

Table 1. Syntax and Semantics of a Calculus for Propositional Logic

The simplest expression for logical truth is the empty word,

the identity element for concatenation. To make it visible

in context, it may be denoted by the equivalent expression

“(())”, or, especially if operating in an algebraic context,
in context, it may be denoted by the equivalent expression

by a simple “1”. Also when working in an algebraic mode, the

plus sign “+” may be used for exclusive disjunction. Thus we

have the following translations of algebraic expressions into

cactus expressions.

• a + b = (a, b)
plus sign “+” may be used for exclusive disjunction. Thus we

have the following translations of algebraic expressions into

cactus expressions.

• a + b + c = (a, (b, c)) = ((a, b), c)

Jun 16, 2021, 4:32:15 PMJun 16

to Cybernetic Communications, Ontolog Forum, Peirce List, Structural Modeling, SysSciWG, Laws of Form

Cf: Differential Logic • Discussion 4

http://inquiryintoinquiry.com/2021/06/16/differential-logic-discussion-4/

Re: Peirce List

https://list.iupui.edu/sympa/arc/peirce-l/2021-06/thrd4.html#00078

::: Mauro Bertani

https://list.iupui.edu/sympa/arc/peirce-l/2021-06/msg00109.html

<QUOTE MB:>

About Lobe Connective and Node Connective and their consequences,

I have a question:

You say that genus and species are evaluated by the proposition (a, (b),(c)).

The following proposition would no longer be appropriate: a (b, c).

And another question about differential calculus:

When we talk about A and dA we talk about A and (A)

or is it more similar to A and B?

</QUOTE>

Dear Mauro,

The proposition (a, (b),(c)) describes a genus a divided into species b and c.

The proposition a (b, c) says a is always true while just one of b or c is true.

The first proposition leaves space between the whole universe and the genus a

while the second proposition identifies the genus a with the whole universe.

The differential proposition dA is one we use to describe a change of state

(or a state of change) from A to (A) or the reverse.

Resources

=========

• Logic Syllabus ( https://oeis.org/wiki/Logic_Syllabus )

• Logical Graphs ( https://oeis.org/wiki/Logical_Graphs )

• Minimal Negation Operators ( https://oeis.org/wiki/Minimal_negation_operator )

http://inquiryintoinquiry.com/2021/06/16/differential-logic-discussion-4/

Re: Peirce List

https://list.iupui.edu/sympa/arc/peirce-l/2021-06/thrd4.html#00078

::: Mauro Bertani

https://list.iupui.edu/sympa/arc/peirce-l/2021-06/msg00109.html

<QUOTE MB:>

About Lobe Connective and Node Connective and their consequences,

I have a question:

You say that genus and species are evaluated by the proposition (a, (b),(c)).

The following proposition would no longer be appropriate: a (b, c).

And another question about differential calculus:

When we talk about A and dA we talk about A and (A)

or is it more similar to A and B?

</QUOTE>

Dear Mauro,

The proposition (a, (b),(c)) describes a genus a divided into species b and c.

The proposition a (b, c) says a is always true while just one of b or c is true.

The first proposition leaves space between the whole universe and the genus a

while the second proposition identifies the genus a with the whole universe.

The differential proposition dA is one we use to describe a change of state

(or a state of change) from A to (A) or the reverse.

Resources

=========

• Logic Syllabus ( https://oeis.org/wiki/Logic_Syllabus )

• Logical Graphs ( https://oeis.org/wiki/Logical_Graphs )

• Minimal Negation Operators ( https://oeis.org/wiki/Minimal_negation_operator )

Jun 17, 2021, 12:15:25 PMJun 17

Cf: Differential Logic • Discussion 5

http://inquiryintoinquiry.com/2021/06/17/differential-logic-discussion-5/

Re: Laws of Form

https://groups.io/g/lawsofform/topic/differential_logic/83557540

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/330 )

<QUOTE JA:>

<QUOTE LA:>

Does this mean that if A is the proposition “The sky is blue”,

then dA would be the statement “The sky is not blue”? Don't

you already have a notation for this in A and (A) ? From

where does “state” and “change of state” come in relation

to a proposition?

</QUOTE>

Dear Lyle,

The differential variable dA : X → B = {0, 1} is a derivative variable,

a qualitative analogue of a velocity vector in the quantitative realm.

Let's say x ϵ R is a real value giving the membrane potential

in a particular segment of a nerve cell's axon and A : R → B

is a categorical variable predicating whether the site is in

the activated state, A(x) = 1, or not, A(x) = 0. We observe

the site at discrete intervals, a few milliseconds apart, and

obtain the following data.

• At time t₁ the site is in a resting state, A(x) = 0.

• At time t₂ the site is in an active state, A(x) = 1.

• At time t₃ the site is in a resting state, A(x) = 0.

On current information we have no way of predicting the state at

time t₂ from the state at time t₁ but we know action potentials

are inherently transient so we can fairly well guess the state

of change at time t₂ is dA = 1, in other words, about to be

changing from A to (A). The site's qualitative “position”

and “velocity” at time t₂ can now be described by means

of the compound proposition A dA.

Resources

=========

Logic Syllabus

https://oeis.org/wiki/Logic_Syllabus

Logical Graphs

https://oeis.org/wiki/Logical_Graphs

Minimal Negation Operators

https://oeis.org/wiki/Minimal_negation_operator

Differential Logic

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3

http://inquiryintoinquiry.com/2021/06/17/differential-logic-discussion-5/

Re: Laws of Form

https://groups.io/g/lawsofform/topic/differential_logic/83557540

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/330 )

<QUOTE JA:>

The differential proposition dA is one we use to describe

a change of state (or a state of change) from A to (A) or

the reverse.

</QUOTE>
a change of state (or a state of change) from A to (A) or

the reverse.

<QUOTE LA:>

Does this mean that if A is the proposition “The sky is blue”,

then dA would be the statement “The sky is not blue”? Don't

you already have a notation for this in A and (A) ? From

where does “state” and “change of state” come in relation

to a proposition?

</QUOTE>

Dear Lyle,

The differential variable dA : X → B = {0, 1} is a derivative variable,

a qualitative analogue of a velocity vector in the quantitative realm.

Let's say x ϵ R is a real value giving the membrane potential

in a particular segment of a nerve cell's axon and A : R → B

is a categorical variable predicating whether the site is in

the activated state, A(x) = 1, or not, A(x) = 0. We observe

the site at discrete intervals, a few milliseconds apart, and

obtain the following data.

• At time t₁ the site is in a resting state, A(x) = 0.

• At time t₂ the site is in an active state, A(x) = 1.

• At time t₃ the site is in a resting state, A(x) = 0.

On current information we have no way of predicting the state at

time t₂ from the state at time t₁ but we know action potentials

are inherently transient so we can fairly well guess the state

of change at time t₂ is dA = 1, in other words, about to be

changing from A to (A). The site's qualitative “position”

and “velocity” at time t₂ can now be described by means

of the compound proposition A dA.

Resources

=========

Logic Syllabus

https://oeis.org/wiki/Logic_Syllabus

Logical Graphs

https://oeis.org/wiki/Logical_Graphs

Minimal Negation Operators

https://oeis.org/wiki/Minimal_negation_operator

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3

Jun 17, 2021, 6:45:44 PMJun 17

Cf: Differential Logic • 4

https://inquiryintoinquiry.com/2020/03/26/differential-logic-4/

Differential Expansions of Propositions

=======================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

Bird’s Eye View

===============

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Bird.27s_Eye_View

An efficient calculus for the realm of logic represented by boolean functions

and elementary propositions makes it feasible to compute the finite differences

and the differentials of those functions and propositions.

For example, consider a proposition of the form “p and q”

graphed as two letters attached to a root node, as shown below.

Figure 1. Cactus Graph Existential p and q

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-existential-p-and-q.jpg

Written as a string, this is just the concatenation “p q”.

The proposition pq may be taken as a boolean function f(p, q)

having the abstract type f : B × B → B, where B = {0, 1} is

Figure 3. Cactus Graph (p, dp)(q, dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdq-1.jpg

The cactus formula (p, dp)(q, dq) and its corresponding graph arise

by replacing p with p + dp and q with q + dq in the boolean product

Figure 4. Cactus Graph (p, dp)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdp-1.jpg

Next question: What is the difference between the value of

the proposition pq over there, at a distance of dp and dq from

where you are standing, and the value of the proposition pq where

you are, all expressed in the form of a general formula, of course?

The answer takes the following form.

Figure 5. Cactus Graph ((p, dp)(q, dq), pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdqpq-1.jpg

There is one thing I ought to mention at this point: Computed over B,

plus and minus are identical operations. This will make the relation

between the differential and the integral parts of the appropriate

calculus slightly stranger than usual, but we will get into that later.

Last question, for now: What is the value of this expression from your

current standpoint, that is, evaluated at the point where pq is true?

Well, replacing p with 1 and q with 1 in the cactus graph amounts to

erasing the labels p and q, as shown below.

Figure 6. Cactus Graph (( , dp)( , dq), )

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dp-dq-1-1.jpg

And this is equivalent to the following graph.

Figure 7. Cactus Graph ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dpdq-1.jpg

We have just met with the fact

that the differential of the AND

is the OR of the differentials.

• p and q ---Diff---> dp or dq

Figure 8. Cactus Graph pq Diff ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pq-diff-dpdq-1.jpg

It will be necessary to develop a more refined analysis of

that statement directly, but that is roughly the nub of it.

If the form of the above statement reminds you of De Morgan's rule,

it is no accident, as differentiation and negation turn out to be

closely related operations. Indeed, one can find discussions of

logical difference calculus in the Boole–De Morgan correspondence

but see the blog post linked at top of the page for the Figures and

also for the proper math formatting.

Regards,

Jon

https://inquiryintoinquiry.com/2020/03/26/differential-logic-4/

Differential Expansions of Propositions

=======================================

Bird’s Eye View

===============

An efficient calculus for the realm of logic represented by boolean functions

and elementary propositions makes it feasible to compute the finite differences

and the differentials of those functions and propositions.

graphed as two letters attached to a root node, as shown below.

Figure 1. Cactus Graph Existential p and q

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-existential-p-and-q.jpg

Written as a string, this is just the concatenation “p q”.

The proposition pq may be taken as a boolean function f(p, q)

read in such a way that 0 means false and 1 means true.

Imagine yourself standing in a fixed cell of the corresponding

venn diagram, say, the cell where the proposition pq is true,

Imagine yourself standing in a fixed cell of the corresponding

venn diagram, say, the cell where the proposition pq is true,

as shown in the following Figure.

Figure 2. Venn Diagram p and q
https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-and-q.jpg

Now ask yourself: What is the value of the proposition pq

at a distance of dp and dq from the cell pq where you are

standing?

Don't think about it — just compute:
Now ask yourself: What is the value of the proposition pq

at a distance of dp and dq from the cell pq where you are

standing?

Figure 3. Cactus Graph (p, dp)(q, dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdq-1.jpg

The cactus formula (p, dp)(q, dq) and its corresponding graph arise

or logical conjunction pq and writing the result in the two dialects

of cactus syntax. This follows because the boolean sum p + dp is
equivalent to the logical operation of exclusive disjunction, which

parses to a cactus graph of the following form.
Figure 4. Cactus Graph (p, dp)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdp-1.jpg

Next question: What is the difference between the value of

where you are standing, and the value of the proposition pq where

you are, all expressed in the form of a general formula, of course?

The answer takes the following form.

Figure 5. Cactus Graph ((p, dp)(q, dq), pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pdpqdqpq-1.jpg

There is one thing I ought to mention at this point: Computed over B,

plus and minus are identical operations. This will make the relation

between the differential and the integral parts of the appropriate

calculus slightly stranger than usual, but we will get into that later.

Last question, for now: What is the value of this expression from your

current standpoint, that is, evaluated at the point where pq is true?

erasing the labels p and q, as shown below.

Figure 6. Cactus Graph (( , dp)( , dq), )

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dp-dq-1-1.jpg

And this is equivalent to the following graph.

Figure 7. Cactus Graph ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-dpdq-1.jpg

We have just met with the fact

is the OR of the differentials.

• p and q ---Diff---> dp or dq

Figure 8. Cactus Graph pq Diff ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-pq-diff-dpdq-1.jpg

It will be necessary to develop a more refined analysis of

that statement directly, but that is roughly the nub of it.

If the form of the above statement reminds you of De Morgan's rule,

it is no accident, as differentiation and negation turn out to be

closely related operations. Indeed, one can find discussions of

and Peirce also made use of differential operators in a logical

context, but the exploration of these ideas has been hampered by

a number of factors, not the least of which has been the lack of

a syntax adequate to handle the complexity of expressions evolving

in the process.

Note. Due to the large number of Figures I won't attach them here,
context, but the exploration of these ideas has been hampered by

a number of factors, not the least of which has been the lack of

a syntax adequate to handle the complexity of expressions evolving

in the process.

but see the blog post linked at top of the page for the Figures and

also for the proper math formatting.

Regards,

Jon

Jun 18, 2021, 1:49:01 PMJun 18

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • 5

https://inquiryintoinquiry.com/2020/03/28/differential-logic-5/

Differential Expansions of Propositions

=======================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

Worm's Eye View

===============

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Worm.27s_Eye_View

Let's run through the initial example again, keeping an eye

on the meanings of the formulas which develop along the way.

We begin with a proposition or a boolean function f(p, q) = pq

whose venn diagram and cactus graph are shown below.

Figure 1. Venn Diagram f = pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-f-p-and-q.jpg

Figure 2. Cactus Graph f = pq

account the qualitative dimensions or “units” of the case,

• Let Q be the set of values {(q), q} = {not q, q} ≅ B.

Then interpret the usual propositions about p, q

as functions of the concrete type f : P × Q → B.

We are going to consider various “operators” on these functions.

An operator F is a function which takes one function f into

another function Ff.

The first couple of operators we need to consider are logical

analogues of two which play a founding role in the classical

finite difference calculus, namely:

• The “difference operator” Δ, written here as D.

• The “enlargement operator”, written here as E.

These days, E is more often called the “shift operator”.

In order to describe the universe in which these operators operate,

it is necessary to enlarge the original universe of discourse.

Starting from the initial space X = P × Q, its “(first order)

• EX = X × dX

where:

• X = P × Q

• dX = dP × dQ

• dP = {(dp), dp}

• dQ = {(dq), dq}

The interpretations of these new symbols can be diverse, but

the easiest option for now is just to say dp means “change p”

and dq means “change q”.

Drawing a venn diagram for the differential extension EX = X × dX

crossing the boundaries of the basic circles in the venn diagram for X,

Figure 3. Venn Diagram p q dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-q-dp-dq.jpg

Note: Given the length of this section I'm going to break here

and continue in the next message, but see the blog post linked

above for the a better copy of the Figures and Math Formatting.

Regards,

Jon

https://inquiryintoinquiry.com/2020/03/28/differential-logic-5/

Differential Expansions of Propositions

=======================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

===============

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Worm.27s_Eye_View

Let's run through the initial example again, keeping an eye

on the meanings of the formulas which develop along the way.

We begin with a proposition or a boolean function f(p, q) = pq

whose venn diagram and cactus graph are shown below.

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-f-p-and-q.jpg

Figure 2. Cactus Graph f = pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-f-p-and-q.jpg

A function like this has an abstract type and a concrete type.

The abstract type is what we invoke when we write things like

f : B × B → B or f : B² → B. The concrete type takes into
A function like this has an abstract type and a concrete type.

The abstract type is what we invoke when we write things like

account the qualitative dimensions or “units” of the case,

which can be explained as follows.

• Let P be the set of values {(p), p} = {not p, p} ≅ B.
• Let Q be the set of values {(q), q} = {not q, q} ≅ B.

Then interpret the usual propositions about p, q

We are going to consider various “operators” on these functions.

An operator F is a function which takes one function f into

another function Ff.

The first couple of operators we need to consider are logical

analogues of two which play a founding role in the classical

finite difference calculus, namely:

• The “enlargement operator”, written here as E.

These days, E is more often called the “shift operator”.

In order to describe the universe in which these operators operate,

it is necessary to enlarge the original universe of discourse.

differential extension” EX is constructed according to the

following specifications.
• EX = X × dX

where:

• X = P × Q

• dX = dP × dQ

• dP = {(dp), dp}

• dQ = {(dq), dq}

The interpretations of these new symbols can be diverse, but

the easiest option for now is just to say dp means “change p”

and dq means “change q”.

requires four logical dimensions, P, Q, dP, dQ, but it is possible

to project a suggestion of what the differential features dp and dq

are about on the 2-dimensional base space X = P × Q by drawing arrows
to project a suggestion of what the differential features dp and dq

crossing the boundaries of the basic circles in the venn diagram for X,

reading an arrow as dp if it crosses the boundary between p and (p) in

either direction and reading an arrow as dq if it crosses the boundary

between q and (q) in either direction, as shown in the following Figure.
either direction and reading an arrow as dq if it crosses the boundary

Figure 3. Venn Diagram p q dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-q-dp-dq.jpg

Note: Given the length of this section I'm going to break here

and continue in the next message, but see the blog post linked

above for the a better copy of the Figures and Math Formatting.

Regards,

Jon

Jun 19, 2021, 1:02:33 PMJun 19

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Differential Expansions of Propositions (cont.)

===============================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

Worm's Eye View (cont.)

=======================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Worm.27s_Eye_View

| Note. In the plaintext transcript below, I will use braces { }

| for function arguments f{x, y} and reserve parentheses ( ) for

| cactus formulas (p) = ¬p, (p, q) = p + q = p XOR q, and so on.

| Please see the blog post linked above for proper math formats.

| Picking up from where we left off last time, we are in the

| process of developing a propositional calculus analogue of

| the classical finite difference calculus, illustrated here

| in the case of the logical conjunction f{p, q} = pq = p∧q.

Drawing a venn diagram for the differential extension EX = X × dX

requires four logical dimensions, P, Q, dP, dQ, but it is possible

to project a suggestion of what the differential features dp and dq

are about on the 2-dimensional base space X = P × Q by drawing arrows

crossing the boundaries of the basic circles in the venn diagram for X,

reading an arrow as dp if it crosses the boundary between p and (p) in

either direction and reading an arrow as dq if it crosses the boundary

between q and (q) in either direction, as shown in the following Figure.

Figure 3. Venn Diagram p q dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-q-dp-dq.jpg

“(first order) enlargement” of f is the proposition Ef over

the differential extension EX defined by the following formula.

• Ef{p, q, dp, dq} = f{p + dp, q + dq} = f{(p, dp), (q, dq)}

In the example f{p, q} = pq, the enlargement Ef is computed as follows.

• Ef{p, q, dp, dq} = {p + dp}{q + dq} = (p, dp)(q, dq)

Figure 4. Cactus Graph Ef = (p,dp)(q,dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq-1.jpg

Given the proposition f{p, q} over the space X = P × Q, the

“(first order) difference” of f is the proposition Df over EX

In the example f{p, q} = pq, the difference Df is computed as follows.

• Df{p, q, dp, dq} = {p + dp}{q + dq} - pq = ((p, dp)(q, dq), pq)

Figure 5. Cactus Graph Df = ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq-1.jpg

At the end of the previous section we evaluated this first order difference of

conjunction Df at a single location in the universe of discourse, namely, at the

point picked out by the singular proposition pq, in terms of coordinates, at the

place where p = 1 and q = 1. This evaluation is written in the form Df|_{pq} or

Df|_{(1, 1)}, and we arrived at the locally applicable law which may be stated

and illustrated as follows.

• f{p, q} = pq = p AND q ⇒ Df|_{pq} = ((dp)(dq)) = dp OR dq

Figure 6. Venn Diagram Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-difference-pq-40-pq.jpg

Figure 7. Cactus Graph Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-difference-pq-40-pq.jpg

The venn diagram shows the analysis of the

inclusive disjunction ((dp)(dq)) into the

following exclusive disjunction.

• dp (dq) + (dp) dq + dp dq

The differential proposition ((dp)(dq)) may be read as saying

“change p or change q or both”. And this can be recognized as

===============================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

Worm's Eye View (cont.)

=======================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Worm.27s_Eye_View

| Note. In the plaintext transcript below, I will use braces { }

| for function arguments f{x, y} and reserve parentheses ( ) for

| cactus formulas (p) = ¬p, (p, q) = p + q = p XOR q, and so on.

| Please see the blog post linked above for proper math formats.

| Picking up from where we left off last time, we are in the

| process of developing a propositional calculus analogue of

| the classical finite difference calculus, illustrated here

| in the case of the logical conjunction f{p, q} = pq = p∧q.

Drawing a venn diagram for the differential extension EX = X × dX

requires four logical dimensions, P, Q, dP, dQ, but it is possible

to project a suggestion of what the differential features dp and dq

are about on the 2-dimensional base space X = P × Q by drawing arrows

crossing the boundaries of the basic circles in the venn diagram for X,

reading an arrow as dp if it crosses the boundary between p and (p) in

either direction and reading an arrow as dq if it crosses the boundary

between q and (q) in either direction, as shown in the following Figure.

Figure 3. Venn Diagram p q dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-p-q-dp-dq.jpg

Propositions are formed on differential variables, or any combination of

ordinary logical variables and differential logical variables, in the

same ways propositions are formed on ordinary logical variables alone.

For example, the proposition (dp (dq)) says the same thing as dp ⇒ dq,
ordinary logical variables and differential logical variables, in the

same ways propositions are formed on ordinary logical variables alone.

in other words, there is no change in p without a change in q.

Given the proposition f{p, q} over the space X = P × Q, the
“(first order) enlargement” of f is the proposition Ef over

the differential extension EX defined by the following formula.

• Ef{p, q, dp, dq} = f{p + dp, q + dq} = f{(p, dp), (q, dq)}

In the example f{p, q} = pq, the enlargement Ef is computed as follows.

• Ef{p, q, dp, dq} = {p + dp}{q + dq} = (p, dp)(q, dq)

Figure 4. Cactus Graph Ef = (p,dp)(q,dq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq-1.jpg

Given the proposition f{p, q} over the space X = P × Q, the

“(first order) difference” of f is the proposition Df over EX

defined by the formula Df = Ef - f, or, written out in full:

• Df{p, q, dp, dq} = f{p + dp, q + dq} - f{p, q} = ( f{ (p, dp), (q, dq) }, f{p, q} )
In the example f{p, q} = pq, the difference Df is computed as follows.

• Df{p, q, dp, dq} = {p + dp}{q + dq} - pq = ((p, dp)(q, dq), pq)

Figure 5. Cactus Graph Df = ((p,dp)(q,dq),pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq-1.jpg

At the end of the previous section we evaluated this first order difference of

conjunction Df at a single location in the universe of discourse, namely, at the

point picked out by the singular proposition pq, in terms of coordinates, at the

place where p = 1 and q = 1. This evaluation is written in the form Df|_{pq} or

Df|_{(1, 1)}, and we arrived at the locally applicable law which may be stated

• f{p, q} = pq = p AND q ⇒ Df|_{pq} = ((dp)(dq)) = dp OR dq

Figure 6. Venn Diagram Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/venn-diagram-difference-pq-40-pq.jpg

Figure 7. Cactus Graph Difference pq @ pq

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-difference-pq-40-pq.jpg

The venn diagram shows the analysis of the

following exclusive disjunction.

• dp (dq) + (dp) dq + dp dq

The differential proposition ((dp)(dq)) may be read as saying

“change p or change q or both”. And this can be recognized as

Jun 19, 2021, 3:12:35 PMJun 19

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 6

https://inquiryintoinquiry.com/2021/06/19/differential-logic-discussion-6/

Re: Differential Logic • 5

https://inquiryintoinquiry.com/2020/03/28/differential-logic-5/

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/338 )

<QUOTE JA:>

<QUOTE LA:>

Is this what is new: “you happen to find yourself in the center cell

[of a Venn diagram] and require a complete and detailed description of

ways to escape it”?

</QUOTE>

Dear Lyle,

What's improved, if not entirely new, is the development of appropriate

logical analogues of differential calculus and differential geometry.

There has been work on applying the calculus of finite differences to

propositions, but the traditional styles of syntax are so weighed down

by conceptual clutter that the resulting formal systems hardly get off

the ground before they become too unwieldy to stand.

That is where the formal elegance and practical efficiency of C.S. Peirce's

logical graphs and Spencer Brown's graphical forms come to save the day.

That, I think, is new. Or at least it was when I began work on it.

Regards,

Jon (the Prisoner of Vennda, No More)

https://inquiryintoinquiry.com/2021/06/19/differential-logic-discussion-6/

Re: Differential Logic • 5

https://inquiryintoinquiry.com/2020/03/28/differential-logic-5/

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/338 )

<QUOTE JA:>

The differential proposition ((dp)(dq)) may be read as saying

“change p or change q or both”. And this can be recognized as

just what you need to do if you happen to find yourself in the

center cell and require a complete and detailed description of

ways to escape it.

</QUOTE>
“change p or change q or both”. And this can be recognized as

just what you need to do if you happen to find yourself in the

center cell and require a complete and detailed description of

ways to escape it.

<QUOTE LA:>

Is this what is new: “you happen to find yourself in the center cell

[of a Venn diagram] and require a complete and detailed description of

ways to escape it”?

</QUOTE>

Dear Lyle,

What's improved, if not entirely new, is the development of appropriate

logical analogues of differential calculus and differential geometry.

There has been work on applying the calculus of finite differences to

propositions, but the traditional styles of syntax are so weighed down

by conceptual clutter that the resulting formal systems hardly get off

the ground before they become too unwieldy to stand.

That is where the formal elegance and practical efficiency of C.S. Peirce's

logical graphs and Spencer Brown's graphical forms come to save the day.

That, I think, is new. Or at least it was when I began work on it.

Regards,

Jon (the Prisoner of Vennda, No More)

Jun 20, 2021, 12:00:26 PMJun 20

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 7

https://inquiryintoinquiry.com/2021/06/20/differential-logic-discussion-7/

Re: Differential Logic • 1

https://inquiryintoinquiry.com/2020/03/22/differential-logic-1/

Re: FB | Pattern Languages for Systemic Transformation

https://www.facebook.com/groups/125513674232534/permalink/4051794061604456

::: Steve Kramer

https://www.facebook.com/groups/125513674232534/permalink/4051794061604456/?comment_id=4052606854856510

<QUOTE SK:>

Can differential logic be described using category theory?

To what other logical or mathematical modalities does

differential logic relate? Give an example.

Partial credit will be given.

</QUOTE>

Dear Steve,

The ultimate category-theoretic generalization of the

functional derivative in calculus and the tangent vector

in differential geometry is called a “tangent functor”.

Finding the proper logical analogue of a tangent functor

is the main business of my essay on Differential Logic

and Dynamic Systems.

Differential Logic and Dynamic Systems

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_3

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_4

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_5

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Appendices

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_References

But that opus is a lot to take in all at once so over the years

I've tried writing a number of easier pieces to work up to it more

gradually. The first intuitive inklings of the subject are provided

by the following overture.

Differential Propositional Calculus

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Appendices

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_References

The following series provides a more systematic treatment of substantial issues.

Differential Logic

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3

Regards,

Jon

https://inquiryintoinquiry.com/2021/06/20/differential-logic-discussion-7/

Re: Differential Logic • 1

https://inquiryintoinquiry.com/2020/03/22/differential-logic-1/

Re: FB | Pattern Languages for Systemic Transformation

https://www.facebook.com/groups/125513674232534/permalink/4051794061604456

::: Steve Kramer

https://www.facebook.com/groups/125513674232534/permalink/4051794061604456/?comment_id=4052606854856510

<QUOTE SK:>

Can differential logic be described using category theory?

To what other logical or mathematical modalities does

differential logic relate? Give an example.

Partial credit will be given.

</QUOTE>

Dear Steve,

The ultimate category-theoretic generalization of the

functional derivative in calculus and the tangent vector

in differential geometry is called a “tangent functor”.

Finding the proper logical analogue of a tangent functor

is the main business of my essay on Differential Logic

and Dynamic Systems.

Differential Logic and Dynamic Systems

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_3

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_4

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_5

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Appendices

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_References

But that opus is a lot to take in all at once so over the years

I've tried writing a number of easier pieces to work up to it more

gradually. The first intuitive inklings of the subject are provided

by the following overture.

Differential Propositional Calculus

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_Appendices

https://oeis.org/wiki/Differential_Propositional_Calculus_%E2%80%A2_References

The following series provides a more systematic treatment of substantial issues.

Differential Logic

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Overview

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_3

Jon

Jun 26, 2021, 4:16:13 PMJun 26

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • 6

https://inquiryintoinquiry.com/2020/04/03/differential-logic-6/

Differential Expansions of Propositions (cont.)

===============================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

In the previous section we computed what is variously described

as the “difference map”, the “difference proposition”, or the

“local proposition” Dfₓ of the proposition f(p, q) = pq at

pq, p(q), (p)q, (p)(q) indicating the “cells”, or the smallest

at each of the four points x in X may be computed in graphical fashion

as shown below.

Figure 1.0 Cactus Graph Df = ((p, dp)(q, dq), pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq-1.jpg

Figure 1.1 Cactus Graph Difference pq @ pq = ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-difference-pq-40-pq-dpdq.jpg

Figure 1.2 Cactus Graph Difference pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq.jpg

Figure 1.3 Cactus Graph Difference pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq-1.jpg

Figure 1.4 Cactus Graph Difference pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-lobe-rule.jpg

Figure 3. Cactus Graph Spike Rule

or directed graph, one whose points are labeled with the elements

Figure 5. Directed Graph Difference pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-difference-pq.jpg

f = p ∙ q

Df = p ∙ q ∙ ((dp)(dq))

+ p ∙ (q) ∙ (dp) dq

+ (p) ∙ q ∙ dp (dq)

+ (p) ∙ (q) ∙ dp dq

https://inquiryintoinquiry.com/2020/04/03/differential-logic-6/

Differential Expansions of Propositions (cont.)

===============================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

Panoptic View • Difference Maps

===============================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Panoptic_View_.E2.80.A2_Difference_Maps
===============================

In the previous section we computed what is variously described

as the “difference map”, the “difference proposition”, or the

“local proposition” Dfₓ of the proposition f(p, q) = pq at

the point x where p = 1 and q = 1.

In the universe of discourse X = P × Q, the four propositions
pq, p(q), (p)q, (p)(q) indicating the “cells”, or the smallest

distinguished regions of the universe, are called “singular

propositions”. These serve as an alternative notation for

naming the points (1, 1), (1, 0), (0, 1), (0, 0), respectively.

Thus we can write Dfₓ = Df|_x = Df|_(1, 1) = Df|_pq,
propositions”. These serve as an alternative notation for

naming the points (1, 1), (1, 0), (0, 1), (0, 0), respectively.

so long as we know the frame of reference in force.

In the example f(p, q) = pq, the value of the difference proposition Dfₓ
at each of the four points x in X may be computed in graphical fashion

as shown below.

Figure 1.0 Cactus Graph Df = ((p, dp)(q, dq), pq)

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-df-pdpqdqpq-1.jpg

Figure 1.1 Cactus Graph Difference pq @ pq = ((dp)(dq))

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-difference-pq-40-pq-dpdq.jpg

Figure 1.2 Cactus Graph Difference pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq.jpg

Figure 1.3 Cactus Graph Difference pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dpdq-1.jpg

Figure 1.4 Cactus Graph Difference pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-difference-pq-40-pq-dp-dq.jpg

The easy way to visualize the values of these graphical expressions

is just to notice the following equivalents.

Figure 2. Cactus Graph Lobe Rule
The easy way to visualize the values of these graphical expressions

is just to notice the following equivalents.

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-lobe-rule.jpg

Figure 3. Cactus Graph Spike Rule

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-ej-spike-rule.jpg

Laying out the arrows on the augmented venn diagram,

one gets a picture of a differential vector field.

Figure 4. Venn Diagram Difference pq
Laying out the arrows on the augmented venn diagram,

one gets a picture of a differential vector field.

https://inquiryintoinquiry.files.wordpress.com/2020/04/venn-diagram-difference-pq-1.jpg

The Figure shows the points of the extended universe

EX = P × Q × dP × dQ indicated by the difference map

Df : EX → B, namely, the following six points or

singular propositions.

1. p q dp dq

2. p q dp (dq)

3. p q (dp) dq

4. p (q)(dp) dq
The Figure shows the points of the extended universe

EX = P × Q × dP × dQ indicated by the difference map

Df : EX → B, namely, the following six points or

singular propositions.

1. p q dp dq

2. p q dp (dq)

3. p q (dp) dq

5. (p) q dp (dq)

6. (p)(q) dp dq

The information borne by Df should be clear enough from a survey

of these six points — they tell you what you have to do from each

point of X in order to change the value borne by f(p, q), that is,

the move you have to make in order to reach a point where the value

of the proposition f(p, q) is different from what it is where you

started.

We have been studying the action of the difference operator D

on propositions of the form f : P × Q → B, as illustrated by the

example f(p, q) = pq which is known in logic as the conjunction
6. (p)(q) dp dq

The information borne by Df should be clear enough from a survey

of these six points — they tell you what you have to do from each

point of X in order to change the value borne by f(p, q), that is,

the move you have to make in order to reach a point where the value

of the proposition f(p, q) is different from what it is where you

started.

We have been studying the action of the difference operator D

on propositions of the form f : P × Q → B, as illustrated by the

of p and q. The resulting difference map Df is a (first order)

differential proposition, that is, a proposition of the form
Df : P × Q × dP × dQ → B.

The augmented venn diagram shows how the models or satisfying

interpretations of Df distribute over the extended universe of
The augmented venn diagram shows how the models or satisfying

discourse EX = P × Q × dP × dQ. Abstracting from that picture,

the difference map Df can be represented in the form of a digraph
or directed graph, one whose points are labeled with the elements

of X = P × Q and whose arrows are labeled with the elements of

dX = dP × dQ, as shown in the following Figure.
Figure 5. Directed Graph Difference pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-difference-pq.jpg

f = p ∙ q

Df = p ∙ q ∙ ((dp)(dq))

+ p ∙ (q) ∙ (dp) dq

+ (p) ∙ q ∙ dp (dq)

Jul 3, 2021, 9:30:26 AMJul 3

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • 7

https://inquiryintoinquiry.com/2020/04/05/differential-logic-7/

| Note. In the plaintext transcript below, I will use braces { }

| for function arguments f{x, y} and reserve parentheses ( ) for

| cactus formulas (p) = ¬p, (p, q) = p + q = p XOR q, and so on.

| Please see the blog post linked above for proper math formats.

================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Panoptic_View_.E2.80.A2_Enlargement_Maps

The “enlargement” or “shift” operator E exhibits a wealth of

A suitably generic definition of the extended universe of discourse

is afforded by the following set-up.

• Let X = X₁ × … × Xₖ

• Let dX = dX₁ × … × dXₖ

• Then EX = X × dX

= X₁ × … × Xₖ × dX₁ × … × dXₖ

For a proposition of the form f : X₁ × … × Xₖ → B,

= f{x₁ + dx₁, …, xₖ + dxₖ}

= f{(x₁, dx₁), …, (xₖ, dxₖ)}

The differential variables dxₕ are boolean variables of the same type as

the ordinary variables xₕ. Although it is conventional to distinguish the

• Ef{p, q, dp, dq} = {p + dp}{q + dq} = (p, dp)(q, dq)

To understand what the enlarged or shifted proposition means in logical terms,

it serves to go back and analyze the above expression for Ef in the same way

we did for Df. To that end, the value of Efₓ at each x in X may be computed

https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq-1.jpg

Figure 1.1 Cactus Graph Enlargement pq @ pq = (dp)(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq.jpg

Figure 1.2 Cactus Graph Enlargement pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-1.jpg

Figure 1.3 Cactus Graph Enlargement pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-2.jpg

Figure 1.4 Cactus Graph Enlargement pq @ (p)(q) = dp dq

Here is a summary of the result, illustrated by means of a digraph picture,

where the “no change” element (dp)(dq) is drawn as a loop at the point p∙q.

Figure 2. Directed Graph Enlargement pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-enlargement-pq.jpg

• f = p ∙ q

• Ef = p ∙ q ∙ (dp)(dq)

https://inquiryintoinquiry.com/2020/04/05/differential-logic-7/

| Note. In the plaintext transcript below, I will use braces { }

| for function arguments f{x, y} and reserve parentheses ( ) for

| cactus formulas (p) = ¬p, (p, q) = p + q = p XOR q, and so on.

| Please see the blog post linked above for proper math formats.

Differential Expansions of Propositions (cont.)

===============================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

Panoptic View • Enlargement Maps
===============================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Differential_Expansions_of_Propositions

================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_1#Panoptic_View_.E2.80.A2_Enlargement_Maps

The “enlargement” or “shift” operator E exhibits a wealth of

interesting and useful properties in its own right, so it pays

to examine a few of the more salient features playing out on the

surface of our initial example, f{p, q} = pq.
to examine a few of the more salient features playing out on the

A suitably generic definition of the extended universe of discourse

is afforded by the following set-up.

• Let dX = dX₁ × … × dXₖ

• Then EX = X × dX

= X₁ × … × Xₖ × dX₁ × … × dXₖ

For a proposition of the form f : X₁ × … × Xₖ → B,

the “(first order) enlargement” of f is the proposition

Ef : EX → B defined by the following equation.

• Ef{x₁, …, xₖ, dx₁, …, dxₖ}
= f{x₁ + dx₁, …, xₖ + dxₖ}

= f{(x₁, dx₁), …, (xₖ, dxₖ)}

The differential variables dxₕ are boolean variables of the same type as

the ordinary variables xₕ. Although it is conventional to distinguish the

(first order) differential variables with the operational prefix “d” this way

of notating differential variables is entirely optional. It is their existence

in particular relations to the initial variables, not their names, which defines

them as differential variables.

In the example f{p, q} = pq, the enlargement Ef is formulated as follows.
of notating differential variables is entirely optional. It is their existence

in particular relations to the initial variables, not their names, which defines

them as differential variables.

• Ef{p, q, dp, dq} = {p + dp}{q + dq} = (p, dp)(q, dq)

Given that this expression uses nothing more than the boolean ring operations

of addition and multiplication, it is permissible to “multiply things out” in

the usual manner to arrive at the following result.

• Ef{p, q, dp, dq} = p∙q + p∙dq + q∙dp + dp∙dq
of addition and multiplication, it is permissible to “multiply things out” in

the usual manner to arrive at the following result.

To understand what the enlarged or shifted proposition means in logical terms,

it serves to go back and analyze the above expression for Ef in the same way

in graphical fashion as shown below.

Figure 1.0 Cactus Graph Ef = (p,dp)(q,dq)
https://inquiryintoinquiry.files.wordpress.com/2020/03/cactus-graph-ef-pdpqdq-1.jpg

Figure 1.1 Cactus Graph Enlargement pq @ pq = (dp)(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq.jpg

Figure 1.2 Cactus Graph Enlargement pq @ p(q) = (dp)dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-1.jpg

Figure 1.3 Cactus Graph Enlargement pq @ (p)q = dp(dq)

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dpdq-2.jpg

Figure 1.4 Cactus Graph Enlargement pq @ (p)(q) = dp dq

https://inquiryintoinquiry.files.wordpress.com/2020/04/cactus-graph-enlargement-pq-40-pq-dp-dq.jpg

Collating the data of this analysis yields a boolean expansion or

“disjunctive normal form” (DNF) equivalent to the enlarged proposition Ef.

• Ef = pq∙Ef_pq + p(q)∙Ef_p(q) + (p)q∙Ef_(p)q + (p)(q)∙Ef_(p)(q)
Collating the data of this analysis yields a boolean expansion or

“disjunctive normal form” (DNF) equivalent to the enlarged proposition Ef.

Here is a summary of the result, illustrated by means of a digraph picture,

Figure 2. Directed Graph Enlargement pq

https://inquiryintoinquiry.files.wordpress.com/2020/04/directed-graph-enlargement-pq.jpg

• f = p ∙ q

• Ef = p ∙ q ∙ (dp)(dq)

+ p ∙(q) ∙ (dp) dq

+ (p)∙ q ∙ dp (dq)

+ (p)∙(q) ∙ dp dq

+ (p)∙ q ∙ dp (dq)

+ (p)∙(q) ∙ dp dq

Jul 6, 2021, 8:12:20 AMJul 6

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • 8

https://inquiryintoinquiry.com/2020/04/08/differential-logic-8/

Propositional Forms on Two Variables

====================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables

To broaden our experience with simple examples, let's examine

the sixteen functions of concrete type P × Q → B and abstract

type B × B → B. Our inquiry into the differential aspects of

logical conjunction will pay dividends as we study the actions

of E and D on this family of forms.

Table A1 arranges the propositional forms on two variables

in a convenient order, giving equivalent expressions for

each boolean function in several systems of notation.

Jon

https://inquiryintoinquiry.com/2020/04/08/differential-logic-8/

Propositional Forms on Two Variables

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables

To broaden our experience with simple examples, let's examine

the sixteen functions of concrete type P × Q → B and abstract

logical conjunction will pay dividends as we study the actions

of E and D on this family of forms.

Table A1 arranges the propositional forms on two variables

in a convenient order, giving equivalent expressions for

each boolean function in several systems of notation.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Regards,
https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Jon

Jul 6, 2021, 1:08:42 PMJul 6

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • 9

https://inquiryintoinquiry.com/2020/04/11/differential-logic-9/

Propositional Forms on Two Variables

====================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

Regards,

Jon

https://inquiryintoinquiry.com/2020/04/11/differential-logic-9/

Propositional Forms on Two Variables

====================================

https://oeis.org/wiki/Differential_Logic_%E2%80%A2_Part_2#Propositional_Forms_on_Two_Variables

Table A2 arranges the propositional forms on two variables according to

another plan, sorting propositions with similar shapes into seven subclasses.

Thereby hangs many a tale, to be told in time.

Table A2. Propositional Forms on Two Variables
another plan, sorting propositions with similar shapes into seven subclasses.

Thereby hangs many a tale, to be told in time.

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

Regards,

Jon

Jul 7, 2021, 8:00:24 AMJul 7

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Comment 6

https://inquiryintoinquiry.com/2021/07/07/differential-logic-comment-6/

Cf: Category Theory

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/differential.20logic

::: Jon Awbrey

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/differential.20logic/near/245114541

All,

I opened a topic in the “logic” stream of “category theory.zulipchat”

to discuss differential logic in a category theoretic environment and

began by linking a few basic resources.

The topic on logical graphs (

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/logical.20graphs ) introduced a style

of graph-theoretic syntax for propositional logic stemming from the work of Charles S. Peirce and G. Spencer Brown and

touched on a generalization of Peirce's and Spencer Browns's tree-like forms to what graph theorists know as “cactus

graphs” or “cacti”.

Somewhat serendipitously, as it turns out, this cactus syntax is just the thing we need to develop differential

propositional calculus ( https://inquiryintoinquiry.com/2020/02/16/differential-propositional-calculus-overview/ ),

which augments ordinary propositional calculus in the same way the differential calculus of Leibniz and Newton augments

=========

• Differential Logic • Overview

( https://inquiryintoinquiry.com/2020/03/20/differential-logic-overview/ )

• Survey of Differential Logic

( https://inquiryintoinquiry.com/2021/05/15/survey-of-differential-logic-3/ )

Regards,

Jon

https://inquiryintoinquiry.com/2021/07/07/differential-logic-comment-6/

Cf: Category Theory

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/differential.20logic

::: Jon Awbrey

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/differential.20logic/near/245114541

All,

I opened a topic in the “logic” stream of “category theory.zulipchat”

to discuss differential logic in a category theoretic environment and

began by linking a few basic resources.

The topic on logical graphs (

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/logical.20graphs ) introduced a style

of graph-theoretic syntax for propositional logic stemming from the work of Charles S. Peirce and G. Spencer Brown and

touched on a generalization of Peirce's and Spencer Browns's tree-like forms to what graph theorists know as “cactus

graphs” or “cacti”.

Somewhat serendipitously, as it turns out, this cactus syntax is just the thing we need to develop differential

propositional calculus ( https://inquiryintoinquiry.com/2020/02/16/differential-propositional-calculus-overview/ ),

which augments ordinary propositional calculus in the same way the differential calculus of Leibniz and Newton augments

the analytic geometry of Descartes.

Resources
=========

• Differential Logic • Overview

( https://inquiryintoinquiry.com/2020/03/20/differential-logic-overview/ )

• Survey of Differential Logic

( https://inquiryintoinquiry.com/2021/05/15/survey-of-differential-logic-3/ )

Regards,

Jon

Jul 8, 2021, 10:40:27 AMJul 8

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • 10

https://inquiryintoinquiry.com/2020/04/25/differential-logic-10/

It’s been a while, so let’s review …

Tables A1 and A2 showed two ways of organizing the sixteen boolean functions

or propositional forms on two variables, as expressed in several notations.

For ease of reference, here are fresh copies of those Tables.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Table A2. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

We took as our first example the boolean function f₈{p, q} = pq corresponding

two variables f₈{p, q} and gives back a boolean function of four variables,

Ef₈{p, q, dp, dq} or Df₈{p, q, dp, dq}, respectively.

https://inquiryintoinquiry.com/2020/04/25/differential-logic-10/

It’s been a while, so let’s review …

Tables A1 and A2 showed two ways of organizing the sixteen boolean functions

or propositional forms on two variables, as expressed in several notations.

Table A1. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a1.-propositional-forms-on-two-variables.png

Table A2. Propositional Forms on Two Variables

https://inquiryintoinquiry.files.wordpress.com/2020/04/table-a2.-propositional-forms-on-two-variables-1.png

to the logical conjunction p ∧ q and examined how the differential operators

E and D act on f₈. Each differential operator takes a boolean function of
two variables f₈{p, q} and gives back a boolean function of four variables,

Ef₈{p, q, dp, dq} or Df₈{p, q, dp, dq}, respectively.

Jul 11, 2021, 12:54:52 PMJul 11

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 8

https://inquiryintoinquiry.com/2021/07/11/differential-logic-discussion-8/

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/406 )

<QUOTE LA:>

Before we go on to other Boolean functions, can we nail down the relationship between p and dp and q and dq?

</QUOTE>

Dear Lyle,

I wandered into this differential wonderland by following my nose through a budget

of old readings on the calculus of finite differences. It was a long time ago in

a math library not too far away in space but no longer extant in time. None other

than Boole wrote a treatise on the subject and corresponded with De Morgan about it.

I recall picking up the “E” for “enlargement operator” somewhere in that mix. It was

a genuine epiphany. All of which brings me round to think the most felicitous entry

point may be the one I first happened on, as I recounted in the “Chapter on Linear Topics”

( https://inquiryintoinquiry.files.wordpress.com/2021/05/theme-one-guide-e280a2-linear-topics.pdf )

I linked at the end of the following post.

• Differential Logic and Dynamic Systems • Discussion 5

https://inquiryintoinquiry.com/2021/06/13/differential-logic-and-dynamic-systems-discussion-5/

Maybe it will help to go through that ...

Regards,

Jon

https://inquiryintoinquiry.com/2021/07/11/differential-logic-discussion-8/

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/406 )

<QUOTE LA:>

Before we go on to other Boolean functions, can we nail down the relationship between p and dp and q and dq?

</QUOTE>

Dear Lyle,

I wandered into this differential wonderland by following my nose through a budget

of old readings on the calculus of finite differences. It was a long time ago in

a math library not too far away in space but no longer extant in time. None other

than Boole wrote a treatise on the subject and corresponded with De Morgan about it.

I recall picking up the “E” for “enlargement operator” somewhere in that mix. It was

a genuine epiphany. All of which brings me round to think the most felicitous entry

point may be the one I first happened on, as I recounted in the “Chapter on Linear Topics”

( https://inquiryintoinquiry.files.wordpress.com/2021/05/theme-one-guide-e280a2-linear-topics.pdf )

I linked at the end of the following post.

• Differential Logic and Dynamic Systems • Discussion 5

https://inquiryintoinquiry.com/2021/06/13/differential-logic-and-dynamic-systems-discussion-5/

Maybe it will help to go through that ...

Regards,

Jon

Jul 12, 2021, 3:02:25 PMJul 12

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 9

https://inquiryintoinquiry.com/2021/07/12/differential-logic-discussion-9/

:: Lyle Anderson ( https://groups.io/g/lawsofform/message/424 )

<QUOTE LA:>

All I am asking is what is your definition of “dp” in relation to “p”.

So far I have dp is what one has to do to get from p to (p) or from

(p) to p. Is that all there is to it? If that is the case, then

what you are really dealing with is some flavor of Lattice Theory.

</QUOTE>

Dear Lyle,

What we've been doing all along here is taking the things we'd normally

do in a garden variety “calculus of many variables” course with spaces like:

R, R^j, R^j → R, R^j → R^k, ...

and functoring that whole business over to B, in other words,

cranking the analogies as far as we can push them to spaces like:

B, B^j, B^j → B, B^j → B^k, ...

A few analogies are bound to break in transit through the Real-Bool barrier,

once familiar constructions morph into new-fangled configurations, and other

distinctions collapse or “condense” as Spencer Brown called it. Still enough

structure gets preserved overall to reckon the result a kindred subject.

To be continued ...

Jon

https://inquiryintoinquiry.com/2021/07/12/differential-logic-discussion-9/

:: Lyle Anderson ( https://groups.io/g/lawsofform/message/424 )

<QUOTE LA:>

All I am asking is what is your definition of “dp” in relation to “p”.

So far I have dp is what one has to do to get from p to (p) or from

(p) to p. Is that all there is to it? If that is the case, then

what you are really dealing with is some flavor of Lattice Theory.

</QUOTE>

Dear Lyle,

What we've been doing all along here is taking the things we'd normally

do in a garden variety “calculus of many variables” course with spaces like:

R, R^j, R^j → R, R^j → R^k, ...

and functoring that whole business over to B, in other words,

cranking the analogies as far as we can push them to spaces like:

B, B^j, B^j → B, B^j → B^k, ...

A few analogies are bound to break in transit through the Real-Bool barrier,

once familiar constructions morph into new-fangled configurations, and other

distinctions collapse or “condense” as Spencer Brown called it. Still enough

structure gets preserved overall to reckon the result a kindred subject.

To be continued ...

Jon

Jul 13, 2021, 6:18:21 PMJul 13

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 10

https://inquiryintoinquiry.com/2021/07/13/differential-logic-discussion-10/

Re: Laws of Form

https://groups.io/g/lawsofform/topic/differential_logic/83557540

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/424 )

Dear Lyle,

Let's say we're observing a system at discrete intervals of time and

testing whether its state satisfies or falsifies a given predicate or

proposition p at each moment. Then p and dp are two state variables

describing the time evolution of the system. In logical conception p

and dp are independent variables, even if empirical discovery finds

them bound by law.

What gives the differential variable dp its meaning in relation to

the ordinary variable p is not the conventional notation used here

but a class of “temporal inference rules”, in the present example,

the fourfold scheme of inference shown below.

Temporal Inference Rules

https://inquiryintoinquiry.files.wordpress.com/2021/07/temporal-inference-rules-p.png

Regards,

Jon

https://inquiryintoinquiry.com/2021/07/13/differential-logic-discussion-10/

Re: Laws of Form

https://groups.io/g/lawsofform/topic/differential_logic/83557540

::: Lyle Anderson ( https://groups.io/g/lawsofform/message/424 )

Let's say we're observing a system at discrete intervals of time and

testing whether its state satisfies or falsifies a given predicate or

proposition p at each moment. Then p and dp are two state variables

describing the time evolution of the system. In logical conception p

and dp are independent variables, even if empirical discovery finds

them bound by law.

What gives the differential variable dp its meaning in relation to

the ordinary variable p is not the conventional notation used here

but a class of “temporal inference rules”, in the present example,

the fourfold scheme of inference shown below.

Temporal Inference Rules

https://inquiryintoinquiry.files.wordpress.com/2021/07/temporal-inference-rules-p.png

Regards,

Jon

Jul 16, 2021, 7:16:02 PMJul 16

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 11

https://inquiryintoinquiry.com/2021/07/16/differential-logic-discussion-11/

Re: Differential Logic • Discussion 9

https://inquiryintoinquiry.com/2021/07/12/differential-logic-discussion-9/

All,

Let's look more closely at the “functor” from R to B

and the connection it makes between real and boolean

hierarchies of types. There's a detailed discussion

of this analogy in the article and section linked below.

• Differential Logic and Dynamic Systems

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Overview

•• The Analogy Between Real and Boolean Types

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_1#The_Analogy_Between_Real_and_Boolean_Types

Assorted types of mathematical objects seen often enough in practice to

earn themselves common names, along with their more common isomorphisms,

are shown in Table below.

Table 3. Analogy Between Real and Boolean Types

https://inquiryintoinquiry.files.wordpress.com/2021/07/analogy-between-real-and-boolean-types.png

Regards,

Jon

https://inquiryintoinquiry.com/2021/07/16/differential-logic-discussion-11/

Re: Differential Logic • Discussion 9

https://inquiryintoinquiry.com/2021/07/12/differential-logic-discussion-9/

All,

Let's look more closely at the “functor” from R to B

and the connection it makes between real and boolean

hierarchies of types. There's a detailed discussion

of this analogy in the article and section linked below.

• Differential Logic and Dynamic Systems

•• The Analogy Between Real and Boolean Types

https://oeis.org/wiki/Differential_Logic_and_Dynamic_Systems_%E2%80%A2_Part_1#The_Analogy_Between_Real_and_Boolean_Types

Assorted types of mathematical objects seen often enough in practice to

earn themselves common names, along with their more common isomorphisms,

are shown in Table below.

Table 3. Analogy Between Real and Boolean Types

https://inquiryintoinquiry.files.wordpress.com/2021/07/analogy-between-real-and-boolean-types.png

Regards,

Jon

Jul 21, 2021, 9:48:43 AMJul 21

to Cybernetic Communications, Laws of Form, Ontolog Forum, Structural Modeling, SysSciWG

Cf: Differential Logic • Discussion 12

https://inquiryintoinquiry.com/2021/07/21/differential-logic-discussion-12/

Re: Category Theory

https://categorytheory.zulipchat.com/#narrow/stream/232162-learning.3A-show.20and.20tell/topic/Systems.20dynamics

::: John Baez

(1)

https://categorytheory.zulipchat.com/#narrow/stream/232162-learning.3A-show.20and.20tell/topic/Systems.20dynamics/near/196949955

(2)

https://categorytheory.zulipchat.com/#narrow/stream/232162-learning.3A-show.20and.20tell/topic/Systems.20dynamics/near/196950139

<QUOTE JB:>

One thing I'm interested in is functorially relating purely qualitative models to quantitative ones, or mixed

quantitative-qualitative models where you have some numerical information of the sort you describe, but not all of it.

That's a situation we often find ourselves in: having a mixture of quantitative and qualitative information about

what's going on in a complicated system.

When I say “functorially”, I mean for starters: there should be a functor from “quantitative models” of system dynamics

to “qualitative models”.

</QUOTE>

Dear John,

This is something I've been working on. In a turn of phrase I once concocted,

it's like passing from the qualitative theory of differential equations to the

differential theory of qualitative equations.

Cf. Differential Logic

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/differential.20logic

Regards,

Jon

https://inquiryintoinquiry.com/2021/07/21/differential-logic-discussion-12/

Re: Category Theory

https://categorytheory.zulipchat.com/#narrow/stream/232162-learning.3A-show.20and.20tell/topic/Systems.20dynamics

::: John Baez

(1)

https://categorytheory.zulipchat.com/#narrow/stream/232162-learning.3A-show.20and.20tell/topic/Systems.20dynamics/near/196949955

(2)

https://categorytheory.zulipchat.com/#narrow/stream/232162-learning.3A-show.20and.20tell/topic/Systems.20dynamics/near/196950139

<QUOTE JB:>

One thing I'm interested in is functorially relating purely qualitative models to quantitative ones, or mixed

quantitative-qualitative models where you have some numerical information of the sort you describe, but not all of it.

That's a situation we often find ourselves in: having a mixture of quantitative and qualitative information about

what's going on in a complicated system.

When I say “functorially”, I mean for starters: there should be a functor from “quantitative models” of system dynamics

to “qualitative models”.

</QUOTE>

Dear John,

This is something I've been working on. In a turn of phrase I once concocted,

it's like passing from the qualitative theory of differential equations to the

differential theory of qualitative equations.

Cf. Differential Logic

https://categorytheory.zulipchat.com/#narrow/stream/233104-theory.3A-logic/topic/differential.20logic

Regards,

Jon

Jul 21, 2021, 1:06:58 PMJul 21