Re: William T. Parry gets rid of Disjunction introduction
André G. Isaak <[email protected]>
| Newsgroups | sci.logic,comp.theory,comp.ai.philosophy,sci.math |
|---|---|
| Organization | Christians and Atheists United Against Creeping Agnosticism |
| Message-ID | <[email protected]> |
On 2026-07-07 15:13, olcott wrote: > On 7/7/2026 3:08 PM, André G. Isaak wrote: >> On 2026-07-07 13:53, olcott wrote: >>> On 7/7/2026 2:29 PM, André G. Isaak wrote: >>>> On 2026-07-07 13:19, olcott wrote: >> >>>>> To do with with minimal simplicity the axioms of >>>>> PA are construed as semantic entailment thus when >>>>> there is no sequence of inference steps between G >>>>> and PA then G is Kripke undefined in PA. >>>> >>>> So why don't you illustrate this with an actual proof? >>>> >>>> André >>>> >>> >>> The principle is simply whenever X cannot be proven >>> in F then X is ungrounded in the atomic base F. Even >>> diagonalization makes to attempt at actual proof. >> >> I can't make heads or tails of that. >> > > The actual proof in meta-math that G cannot be > proved in PA is itself not any sequence of inference > steps. It simply uses a version of the proof that > Cantor use to show that reals are not countable. ??? Cantor's proof absolutely contained inference steps, as did Gödels. I don't think you actually know what you're talking about. >> If you can't illustrate your alleged system with a simple proof, then >> I have no choice but to conclude that it is as ill-defined to you as >> it is to me. >> >> André >> > > 2 + 3 = 4 in PA cannot be proven because > s(s(0)) + s(s(s(0))) != s(s(s(s(0)))) I asked you to provide an example of a proof which illustrates what you mean by "semantic entailments encoded syntactically in the language". I didn't ask for an example of something which cannot be proven. André -- To email remove 'invalid' & replace 'gm' with well known Google mail service.