Re: Within Proof Theoretic Semantics Gödel's G h as no meaning in PA
Mikko <[email protected]>
| Newsgroups | sci.logic,sci.math,sci.math.symbolic,comp.theory,comp.ai.philosophy |
|---|---|
| Organization | A noiseless patient Spider |
| Message-ID | <[email protected]> |
On 05/07/2026 19:33, olcott wrote: > On 7/5/2026 9:52 AM, Tristan Wibberley wrote: >> On 04/07/2026 16:31, Tristan Wibberley wrote: >>> On 06/05/2026 20:37, Julio Di Egidio wrote: >>>> On 02/05/2026 20:47, Scott Hoge wrote: >>>> >>>>> In Cantor's theorem, we do not actually construct a diagonal. >>>>> Rather, we presuppose that we can enumerate a set, and then, >>>>> /purely on the grounds of possibility/, conceive a diagonalized >>>>> non-element. >>>> >>>> Nope, as explained and re-explained ad nauseam around here: >>>> just the resident trolls won't get it. >>>> >>>> Cantor's diagonal argument, the one with the binary sequences, >>>> is indeed constructive: a definition of anti-diagonal of *any* >>>> (infinite) list is provided, and the proof that the anti-diagonal >>>> cannot be in the list is quite constructive. >>> >>> "quite" but not "completely". >>> >>> A constructive operation is defined, but a diagonal number is >>> constructed just when that constructive operation is applied to a >>> constructible list. >> >> I should note for the less knowledgable readers of course it's less >> often than that, it is only that often for systems such as the one Julio >> and Phoenix are using which allows dequantification of universally >> quantified statements into the system proper which then have derivable >> statements containing actual constructions of the constructible objects >> they apply to by virtue of their original quantification. Of course, >> dequantification of fantastically quantified statements doesn't make a >> statement about nonconstructible objects because there aren't any >> outside of the fantastical quantification. >> >> By which I don't mean to argue the countability of the set of reals as >> defined in what we call Cantor's Proof of the Uncountability of the >> Reals to include objects quantified over by fantatstical quantification >> but not by universal quantification, but it does make some meaning >> clearer. >> >> While some of the sets might have objects in the system proper, some of >> the members of some of the sets clearly do not. >> > > % This sentence is not true. > ?- LP = not(true(LP)). > LP = not(true(LP)). > ?- unify_with_occurs_check(LP, not(true(LP))). > false. > > Olcott's Minimal Type Theory > G ↔ ¬Prov_PA(⌜G⌝) > Directed Graph of evaluation sequence > 00 ↔ 01 02 > 01 G > 02 ¬ 03 > 03 Prov_PA 04 > 04 Gödel_Number_of 01 // cycle indicates no well-founded justification > tree exists. That is false. There is no evaluation of G in the determination of the Gödel number of anything. Therefore the claim of a loop is false. That error has already been pointed out but Olcott still hopes that someone might bite the bait and the hook. -- Mikko