On Monday, April 10, 2023 at 1:12:45 PM UTC-5, olcott wrote:
> On 4/9/2023 7:51 PM, Mitchell Smith wrote:
> > On Sunday, April 9, 2023 at 10:01:47 AM UTC-5, olcott wrote:
> >> On 4/9/2023 9:01 AM, Mitchell Smith wrote:
> >>> On Saturday, April 8, 2023 at 2:17:04 PM UTC-5, olcott wrote:
> >>>> Well-formed formulas have meaning only when an interpretation is given
> >>>> for the symbols. Mendelson
> >>>>
> >>>> No one seems to know why model theory is needed.
> >>>> A ∧ B → A is known to be true on the basis of the meaning of the
> >>>> symbols, no model theory needed.
> >>>>
> >>>> --
> >>>> Copyright 2023 Olcott "Talent hits a target no one else can hit; Genius
> >>>> hits a target no one else can see." Arthur Schopenhauer
> >>> Peter,
> >>>
> >>> A similar question had been asked on MSE two years ago. I have no reason to join the auspicious minds of MSE (who practice censorship), but, I have occasionally answered as a guest.
> >>>
> >>> I gave a two-part answer to the question at the link,
> >>>
> >>>
https://math.stackexchange.com/questions/3970711/what-is-the-point-of-model-theory
> >>>
> >>> under 'mls'.
> >>>
> >>> You may find it informative. The original poster did accept my answer.
> >> I looked at this. What I really need to start with is the gist of the
> >> purpose of model theory. It looks like it simply defines sets that the
> >> variables range over, just like the syllogism.
> >> --
> >> Copyright 2023 Olcott "Talent hits a target no one else can hit; Genius
> >> hits a target no one else can see." Arthur Schopenhauer
> >
> > Peter,
> >
> > Ask yourself, "What is the role of truth in a proof?"
> >
> Since my goal is to correctly mathematically formalize the notion of
> analytic truth I always go the opposite direction:
>
> What is the role of formal proof in the notion of analytic truth?
> > Truth governs the transition between statements. This is why one speaks of a rule of detachment. A true conclusion is obtained from true premises.
> >
> Since {true} is a semantic concept the correct evaluation of the truth
> of expressions of language cannot correctly be made apart form
> semantics.
> > But, rules of detachment can be declared to be merely syntactic.
> Semantic can be specified syntactically as Rudolf Carnap meaning
> postulates have proved.
> > At issue, then, is the distinction between a semantic conception of truth and an analytical conception of truth.
> They are the same unless terms of the art overrides the conventional
> meaning of these terms.
>
> That cats are animals is analyzed on the basis of the semantic meaning
> of these terms.
> > Many of your statements are compatible with the historical development of analytical truth. But, this is relegated to intensional logic. The traditional interpretation of Goedel's incompleteness theorem involves distinguishing between truth and provability, and, in turn, this distinction depends upon a semantic conception of truth interpreted as a correspondence theory. Meaning postulates do not --- and cannot --- be used to assert that a term denotes an object.
> >
> > I agree that all one can eventually conclude from "the received view" is that words are being used to explain words. So, there is something not quite right about all of this "truth talk."
> The entire body of the analytic side of the analytic syntactic
> distinction is entirely specified as relations between otherwise
> meaningless terms.
>
> ALL of the meaning of every natural language or formal language term is
> entirely encapsulated in its relation to other terms.
> > The word describing this problem is "deflation," and, it goes all of the way back to Aristotle.
> >
> > The link,
> >
> >
https://drive.google.com/file/d/1EUTImanTxstmDEBBNr_sJGq5m-Rh9JkG/view?usp=drivesdk
> >
> > contains a translation from Aristotle's book Categories which I have augmented with my own interpretations relative to my personal knowledge of modern topics.
> >
> > At the top of page 3, Aristotle speaks of "existence" and "the truth of statements" being reciprocal. Then, he observes that the truth of a statement does not imply existence. So, the reciprocity corresponds with the deflationary nature of truth while the residual asymmetry justifies studying truth as a correspondence principle.
> >
> That sound incoherent to me.
> > It is difficult to see how these can be studied "univocally" within the same paradigm. And, deflationism, itself, has numerous philosophical aspects,
> >
> >
https://plato.stanford.edu/entries/truth-deflationary/
> >
> > So, while I can find a quote from Aristotle interpretable with respect to these difficulties, I certainly cannot find a formalization for every nuance that philosophers can imagine.
> >
> > The first-order paradigm is "a way of studying" mathematics which presupposes a correspondence theory of truth relative to fixed domains of discourse.
> The correspondence theory of truth only applies to empirical truth.
> A set of physical sensations corresponds to "there is a TV in my living
> room right now"
>
> Analytic truth is purely axiomatic.
> > If you are going to claim that a different paradigm accounts for mathematics, you must accommodate the fact that first-order logic is a part of mathematics.
> >
> *Introducing the foundation of correct reasoning*
> (the actual way that analytical truth really works)
>
> Just like with syllogisms conclusions are a semantically necessary
> consequence of their premises
>
> Semantic Necessity operator: ⊨□
>
> (a) Some expressions of language L are stipulated to have the semantic
> property of Boolean true.
> (b) Some expressions of language L are a semantically necessary
> consequence of others.
> P is a subset of expressions of language L
> T is a subset of (a)
>
> Provable(P,X) means P ⊨□ X
> True(X) means X ∈ (a) or T ⊨□ X
> False(X) means T ⊨□ ~X
> > This cannot be done by any method which equates truth with provability.
> I just showed the actual inherently correct precise relation between
> truth and provability.
>
> The sequence of truth preserving inference steps from (a) to X <is> the
> relation between truth and provability.
> > This very problem is seen with homotopy type theory and its promoters seem only to concern themselves with winning an argument.
> >
> > And, for what this might be worth, whereas mathematicians communicate with proofs, those who apply mathematics are not under a similar constraint. So, how truth is understood relative to proofs is an aspect of mathematics which introduces these problems involving semantics. I may choose to study mathematics differently from a first-order logician, but, I have an understanding of why I must respect how first-order logicians apply their paradigm. I only take issue with "foundational" claims. It took many years until I could defend the first-order paradigm in spite of not being convinced of its wider claims.
> --
> Copyright 2023 Olcott "Talent hits a target no one else can hit; Genius
> hits a target no one else can see." Arthur Schopenhauer
Peter,
First, let me compliment you on your grasp of an analytic conception of truth. I accept many of your responses.
I reject the idea that you are unable to comprehend a correspondence theory of truth. So, avoiding an admission of different paradigms with the claim that you are in possession of knowledge of "correct reasoning" appears to me as outright dishonesty.
As for what you described as incoherent, I will gladly take some blame. I would not be the first peron to express a difficult statement with intractable syntax. But, it makes me think of three statements:
1) I presume that you are using an electronic device capable of computation to read my words.
2) The phrase, "the electronic device you are using to read my words," is, therefore, a meaningful phrase.
3) The actual, material object allowing you to read my words is not the phrase, "the electronic device you are using to read my words.
With regard to a different issue, the classical division between syntax and semantics is often described as avoiding circularities which must exist in dictionaries providing meanings.
It would seem, then, that your system must be grounded on circular syntactic forms in some way.
I have never seen any such syntax in any of your posts.
Can you demonstrate such a "starting point" or explain how your system avoids circular syntax?
mitch