Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: =?UTF-8?Q?Re=3A_Analysis_of_Flibble=E2=80=99s_Latest=3A_Detecting_v?= =?UTF-8?Q?s=2E_Simulating_Infinite_Recursion_ZFC?= Date: Thu, 22 May 2025 12:13:39 -0500 Organization: A noiseless patient Spider Lines: 48 Message-ID: <100nm04$3inhu$1@dont-email.me> References: <95db078e80b2868ed15a9a9a2af0280d96234a3a@i2pn2.org> <100jo18$2mhfd$1@dont-email.me> <100jpv9$2m0ln$4@dont-email.me> <100kt0c$2tae8$3@dont-email.me> <100ktr7$2reaa$1@dont-email.me> <100l09v$2tae8$5@dont-email.me> <100l1ov$2ul3j$1@dont-email.me> <100l3jh$2v0e9$1@dont-email.me> <100l5c8$2ul3j$2@dont-email.me> <100l75g$2vpq3$1@dont-email.me> <100l887$2ul3i$2@dont-email.me> <100l9gh$30aak$1@dont-email.me> <100lc4o$30pgm$1@dont-email.me> <100ld1u$312c9$1@dont-email.me> <100lg4g$31jt3$1@dont-email.me> <100lkdv$32ib3$1@dont-email.me> <100lmif$32v06$1@dont-email.me> <100lmp3$32ven$1@dont-email.me> <9af78257f75aa43a76d4b75e226bf92aeaf62463@i2pn2.org> <100ngbr$3hg1k$1@dont-email.me> <100ngkv$3hhar$1@dont-email.me> <100nhno$3hg1k$2@dont-email.me> <100njq7$3i5b8$1@dont-email.me> <100nkbo$3hsio$1@dont-email.me> <100nl50$3i5b8$2@dont-email.me> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Thu, 22 May 2025 19:13:40 +0200 (CEST) Injection-Info: dont-email.me; posting-host="1445173336acf9f867010d2c7ad38e9f"; logging-data="3759678"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/duUulhaTSPrmTddq3Xj3f" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:4pbpAlL2h+mHfa6mC9iSuRCIAws= In-Reply-To: <100nl50$3i5b8$2@dont-email.me> Content-Language: en-US X-Antivirus: Norton (VPS 250522-4, 5/22/2025), Outbound message X-Antivirus-Status: Clean On 5/22/2025 11:59 AM, Richard Heathfield wrote: > On 22/05/2025 17:45, olcott wrote: > > > >> You don't have a clue: > > Righty-ho. > >> https://en.wikipedia.org/wiki/Halting_problem#Proof_concept > > Is it this bit you mean? > > There are programs (interpreters) that simulate the execution of > whatever source code they are given. Such programs can demonstrate that > a program does halt if this is the case: the interpreter itself will > eventually halt its simulation, which shows that the original program > halted. However, an interpreter will not halt if its input program does > not halt, so this approach cannot solve the halting problem as stated; > it does not successfully answer "does not halt" for programs that do not > halt. > *The part that the actual link links to* https://en.wikipedia.org/wiki/Halting_problem#Proof_concept Christopher Strachey outlined a proof by contradiction that the halting problem is not solvable.[28][29] The proof proceeds as follows: Suppose that there exists a total computable function halts(f) that returns true if the subroutine f halts (when run with no inputs) and returns false otherwise. Now consider the following subroutine: def g(): if halts(g): loop_forever() halts(g) must either return true or false, because halts was assumed to be total. If halts(g) returns true, then g will call loop_forever and never halt, which is a contradiction. If halts(g) returns false, then g will halt, because it will not call loop_forever; this is also a contradiction. Overall, g does the opposite of what halts says g should do, so halts(g) can not return a truth value that is consistent with whether g halts. Therefore, the initial assumption that halts is a total computable function must be false. -- Copyright 2025 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer