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Feb 25, 2016, 4:18:48 PM2/25/16

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What is known, and what is interesting about the composition of ternary

relations? Are there references to ternary relation algebras?

Aug 23, 2016, 12:23:24 PM8/23/16

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On Thursday, February 25, 2016 at 3:18:48 PM UTC-6, geneN wrote:

> What is known, and what is interesting about the composition of ternary

> relations? Are there references to ternary relation algebras?

Algebras that are "relativized" have a natural formulation in terms of
> What is known, and what is interesting about the composition of ternary

> relations? Are there references to ternary relation algebras?

ternary operators. For instance, if you relativize a group by removing

the special standing of the identity then the implicit appearance of

the group identity e in product g.h gets made explicit g/e.h and this

ternary operation becomes the fundamental operation -- with axioms

a/b.b = a; a/a.b = b; (a/b.c)/d.e = a/b.(c/d.e) and ... for Abelian

groups ... a/b.c = c/b.a. This structure T is, itself, a bundle that

has at each point T_a a "group" as its fibre given by the "relativized"

group operations x ._a y = x/a.y; e_a = a; x^{-1} = e/x.e. In addition;

one can also define a uniform group dT by taking a formal quotient a\b

modulo the equivalence a\(b/c.d) = (c/b.a)\d with both of these serving

to identity the product operation (a\b)(c\d) in the group dT. T is

called a "torsor" and is the actual structure that's involved in the

geometries underlying gauge theory rather than Lie groups. A Lie

Torsor.

Another example like this occurs if you take the vector space and

remove the special standing of the 0 vector. In this case; you have TWO

operations -- one for the product [v,r,w] = (1-r)v + rw; and the

terinary sum v - w + x; the original vector space operations being rv =

[0, r, v] and v + w = v - 0 + w. The first operation, here, is

multi-sorted: v, w are vectors; r lies in the coefficient field and the

result [v, r, w] is a vector.

This time, one of the operations can be defined in terms of the other

if the underlying coefficient field is of size > 2; since v - w + x =

[w,1/(1-r),v],r,[w,1/r,x]] for any r other than 0 or 1. If the field is

of size > 3 the sole axioms required are [v, 0, w] = v; [v, 1, w] = w

and [v, rt(1-t), [w, s, x]] = [[v, rt(1-s), w], t, [v, rs(1-t), x]].

For fields of size 3; the operation the brackets introduces is v.w =

[v, -, w] and satisfies the axioms of the commutative version of what's

known as a "quandle" (quandles are algebras used in knot theory) and is

weaker than the axioms for affine geometry over 3-element fields.

Affine geometries over 2-elements fields are not handled by this

approach. But these are already known: they're Boolean algebras.

A similar approach can make the basic operations of a principal bundle;

likewise for associated bundles; over into ternary algebras. A hint of

that is already seen with the approach adopted for vector spaces.

Aug 24, 2016, 1:41:40 PM8/24/16

to

On Thursday, February 25, 2016 at 4:18:48 PM UTC-5, geneN wrote:

> What is known, and what is interesting about the composition of ternary

> relations? Are there references to ternary relation algebras?

Image understanding uses a betweenness relation [a,b,c] to denote the
> What is known, and what is interesting about the composition of ternary

> relations? Are there references to ternary relation algebras?

object b is between objects a and c, and there is a notion of

transitivity (whenever composition) that is appropriate to that field.

The notion of composition however is unsatisfying as the analog of

binary relation composition for a variety of reasons. I have

investigated some conditions under which a relation notion of

composition results in the operation being associative, but my

assumptions are somewhat ad hoc and not satisfying. For example, the

identity relation, whose matrix has 1's on the main diagonal and 0's

elsewhere, isn't the identity element in this algebra.

I think you can find my notes on this at research gate.com, On Ternary

Relation Composition, by Eugene M. Norris

Aug 24, 2016, 1:42:42 PM8/24/16

to

On Thursday, February 25, 2016 at 1:18:48 PM UTC-8, geneN wrote:

> What is known, and what is interesting about the composition of ternary

> relations? Are there references to ternary relation algebras?

Ternary relations are very interesting and absolutely needed in
> What is known, and what is interesting about the composition of ternary

> relations? Are there references to ternary relation algebras?

Abstract algebra. Where binary relations (a,b) are not sufficient as in

a relationship with an x & y axis. Ternary relations (a,b,c) are needed

to resolve and explain relationships with x, y and z axis, where z is a

plane.

Aug 31, 2016, 9:27:33 PM8/31/16

to

On Tuesday, August 23, 2016 at 11:23:24 AM UTC-5, rockbr...@gmail.com

wrote:

I posted a detailed development of this in smr in the 1990's under

"Mark's Elements". This, here,

http://orion.math.iastate.edu/jdhsmith/math/FA2PGvC.pdf

is the first reference I've ever found that uses the same ternary

algebra; but from a cursory reading it appears they don't find the

unifying formulation that handles most or all the fields that I cited

(which, by the way, was uncovered via a partially automated

"theory-generation" process). The operation I alluded to AB = [A, -1,

B] for the 3-element field is generic to all characteristic 3 fields --

it's simply the midpoint. The properties AA = A; AB = BA; A(AB) = B;

A(BC) = (AB)(AC) continue to hold in that setting. Other fields with

odd or 0 characteristic also have the midpoint operator; only those

with characteristic 22 don't. The paper separately treats the cases of

even, odd and zero characteristic fields.

wrote:

> Algebras that are "relativized" have a natural formulation in terms of

> lgebras that are "relativized" have a natural formulation in terms of

> ternary operators. [e.g. Vector Space relativized to Affine Geometry] TWO
> lgebras that are "relativized" have a natural formulation in terms of

> operations -- one for the product [v,r,w] = (1-r)v + rw; and the

> terinary sum v - w + x; the original vector space operations being rv =

> [0, r, v] and v + w = v - 0 + w.

[Affine geometry]
> terinary sum v - w + x; the original vector space operations being rv =

> [0, r, v] and v + w = v - 0 + w.

I posted a detailed development of this in smr in the 1990's under

"Mark's Elements". This, here,

http://orion.math.iastate.edu/jdhsmith/math/FA2PGvC.pdf

is the first reference I've ever found that uses the same ternary

algebra; but from a cursory reading it appears they don't find the

unifying formulation that handles most or all the fields that I cited

(which, by the way, was uncovered via a partially automated

"theory-generation" process). The operation I alluded to AB = [A, -1,

B] for the 3-element field is generic to all characteristic 3 fields --

it's simply the midpoint. The properties AA = A; AB = BA; A(AB) = B;

A(BC) = (AB)(AC) continue to hold in that setting. Other fields with

odd or 0 characteristic also have the midpoint operator; only those

with characteristic 22 don't. The paper separately treats the cases of

even, odd and zero characteristic fields.

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