Path: ...!eternal-september.org!feeder2.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Mikko Newsgroups: comp.theory Subject: Re: The philosophy of logic reformulates existing ideas on a new basis --- infallibly correct Date: Thu, 14 Nov 2024 10:39:25 +0200 Organization: - Lines: 43 Message-ID: References: <4b24331953934da921cb7547b6ee2058ac9e7254@i2pn2.org> <2a5107f331836f388ad259bf310311a393c00602@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Thu, 14 Nov 2024 09:39:26 +0100 (CET) Injection-Info: dont-email.me; posting-host="1f0f31d82d50f73be1c0a631dee9bbf1"; logging-data="2875106"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18Vwl9xQJAlEmHl+Xom34sB" User-Agent: Unison/2.2 Cancel-Lock: sha1:qIUQBBHs6341o6eVEUIEbWufcnE= Bytes: 3466 On 2024-11-13 23:01:50 +0000, olcott said: > On 11/13/2024 4:45 AM, Mikko wrote: >> On 2024-11-12 23:17:20 +0000, olcott said: >> >>> On 11/10/2024 2:36 PM, Alan Mackenzie wrote: >>>> olcott wrote: >>>>> On 11/10/2024 1:04 PM, Alan Mackenzie wrote: >>>> >>>> [ .... ] >>>> >>>>>> I have addressed your point perfectly well.  Gödel's theorem is correct, >>>>>> therefore you are wrong.  What part of that don't you understand? >>>> >>>>> YOU FAIL TO SHOW THE DETAILS OF HOW THIS DOES >>>>> NOT GET RID OF INCOMPLETENESS. >>>> >>>> The details are unimportant.  Gödel's theorem is correct.  Your ideas >>>> contradict that theorem.  Therefore your ideas are incorrect.  Again, the >>>> precise details are unimportant, and you wouldn't understand them >>>> anyway.  Your ideas are as coherent as 2 + 2 = 5. >>>> >>> >>> Incomplete(L) ≡  ∃x ∈ Language(L) ((L ⊬ x) ∧ (L ⊬ ¬x)) >> >> That's correct (although T is usually used instead of L). >> Per this definition the first order group theory and the first order >> Peano arithmetic are incomplete. > > Every language that can by any means express self-contradiction > incorrectly shows that its formal system is incomplete. That "incorrectly shows" is non-sense. A language does not show, incorrectly or otherwise. A proof shows but not incorrectly. But for a proof you need a theory, i.e. more than just a language. That a theory can't prove something is usually not provable in the theory itself but usually needs be proven in another theory, one that can be interpreted as a metatheory. -- Mikko