| Liste des Groupes | Revenir à c theory |
On 2026-07-03 12:12, olcott wrote:It replaces Model theory With PTS.On 7/3/2026 12:17 PM, André G. Isaak wrote:The rest of my post which you snipped and (presumably) ignored explained *why* you are wrong about this. PTS does not reject models or model theory. It simply doesn't rely on model-theoretic semantics. Q *requires* a model.On 2026-07-03 10:48, olcott wrote:Model theory has been expressly off-topic forOn 7/3/2026 9:45 AM, André G. Isaak wrote:>On 2026-07-02 23:02, olcott wrote:>On 7/1/2026 9:03 PM, olcott wrote:>Q cannot do the ∀x without an infinite sequence of steps.>
So your phrasing is good: Q would need something like an infinite sequence of steps (or a single principle that summarizes them) to get the ∀x. Since formal proofs must be finite, and Q lacks the tool (induction) that would allow a finite proof of the infinite claim, the universal statement remains unprovable.
I'm not sure why you are responding to yourself nor who 'your phrasing' refers to since you don't quote anyone. But, assuming we're still talking about ∀ x, S(x) ≠ x in Q, your reasoning is simply off.
>
You *can* prove universally quantified claims in Q, just not that particular claim.
>
What is the reason that (∀x, S(x) ≠ x) cannot be proved in Q?
Because it isn't true in all models of Q,
many weeks in every thread. Whenever you ignore
this the rest of your reply will be ignored.
André
Les messages affichés proviennent d'usenet.