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|    comp.ai.philosophy    |    Perhaps we should ask SkyNet about this    |    59,235 messages    |
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|    Message 59,154 of 59,235    |
|    olcott to Mikko    |
|    Re: The Halting Problem asks for too muc    |
|    22 Jan 26 10:40:20    |
      XPost: sci.logic, sci.math, comp.theory       From: polcott333@gmail.com              On 1/22/2026 2:21 AM, Mikko wrote:       > On 21/01/2026 17:22, olcott wrote:       >> On 1/21/2026 3:03 AM, Mikko wrote:       >>>       >>> No, it hasn't. In the way theories are usually discussed nothing is       >>> "ture in arithmetic". Every sentence of a first order theory that       >>> can be proven in the theory is true in every model theory. Every       >>> sentence of a theory that cannot be proven in the theory is false       >>> in some model of the theory.       >>>       >>>> only because back then proof theoretic semantics did       >>>> not exist.       >>>       >>> Every interpretation of the theory is a definition of semantics.       >>>       >>       >> Meta‑math relations about numbers don’t exist in PA       >> because PA only contains arithmetical relations—addition,       >> multiplication, ordering, primitive‑recursive predicates       >> about numbers themselves—while relations that talk about       >> PA’s own proofs, syntax, or truth conditions live entirely       >> in the meta‑theory;       >       > Methamathematics does not need any other relations between numbers       > than what PA has. But relations that map other things to numbers       > can be useful for methamathematical purposes.       >       >> so when someone appeals to a Gödel‑style relation like       >> “n encodes a proof of this very sentence,” they’re       >> invoking a meta‑mathematical predicate that PA cannot       >> internalize, which is exactly why your framework draws       >> a clean boundary between internal proof‑theoretic truth       >> and external model‑theoretic truth.       >       > Anyway, what can be provven that way is true aboout PA. You can deny       > the proof but you cannot perform what is meta-provably impossible.       >              Gödel’s sentence is not “true in arithmetic.”       It is true only in the meta‑theory, under an       external interpretation of PA (typically the       standard model ℕ). Inside PA itself, the sentence       is not a truth‑bearer at all. The conflation happens       when people treat model‑theoretic truth—truth       in ℕ—as if it were internal truth in PA.              Proof theoretic semantics anchored in axioms       as their basis of truth proves that I have       always been correct about everything that I said.              All five LLMs agree with this immediately after I       force them to actually simulate DD by HHH according       to the semantics if C:              Thus within well-founded proof theoretic semantics       anchored in the operational semantics of the c       programming language HHH(DD) is correct to reject       its input as non-well-founded?              Any cycle in the directed graph of the evaluation       sequence of an expression correctly rejects this       expression as non-well-founded in any proof theoretic       semantics where true is anchored in the axioms of       the system.              Here is the first time that I explicitly referred       to the idea of non-well-founded expressions in proof       theoretic semantics              [True(X) and ~Provable(X) is Impossible] Feb 4, 2018       https://groups.google.com/g/sci.logic/c/7XihPDLDy9s/m/uD6biLdjAwAJ              --       Copyright 2026 Olcott |
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