Path: ...!weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: olcott Newsgroups: comp.theory Subject: Re: Hypothetical possibilities --- Complete Proof Date: Fri, 2 Aug 2024 06:21:17 -0500 Organization: A noiseless patient Spider Lines: 57 Message-ID: References: <9f3112e056ad6eebf35f940c34b802b46addcad4@i2pn2.org> <9d2f2d8a1bf9614b9d8ab56bd500a78075b365e4@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 02 Aug 2024 13:21:18 +0200 (CEST) Injection-Info: dont-email.me; posting-host="49c3b1279a491a49cbaeec74f647ee34"; logging-data="2936775"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/+kkNlAbIu+d/Cltg6aP7i" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:NBlR3PASplSdjhlalfTeitYOJ2o= Content-Language: en-US In-Reply-To: Bytes: 4432 On 8/2/2024 5:19 AM, Mikko wrote: > On 2024-08-01 16:32:23 +0000, olcott said: >> >> >>      If simulating halt decider H correctly simulates its input D >>      until H correctly determines that its simulated D would never >>      stop running unless aborted then >> >>      H can abort its simulation of D and correctly report that D >>      specifies a non-halting sequence of configurations. >> >> >> I spent two years carefully composing the above before I even >> asked professor Sipser to review it. >> >> DDD is correctly emulated by HHH until HHH sees the same >> never ending pattern that anyone else can see. > > Maybe HHH really sees a never ending pattern but that pattern is not > contained in the behaviour specified by DDD and therefore not relevant. > When DDD correctly emulated by HHH keep repeating its first four instructions because it calls HHH(DDD) this does prove that DDD cannot possibly reach its own "ret" instruction and halt, thus DDD correctly emulated by HHH non-halting even when it stops running. _DDD() [00002172] 55 push ebp ; housekeeping [00002173] 8bec mov ebp,esp ; housekeeping [00002175] 6872210000 push 00002172 ; push DDD [0000217a] e853f4ffff call 000015d2 ; call HHH(DDD) [0000217f] 83c404 add esp,+04 [00002182] 5d pop ebp [00002183] c3 ret Size in bytes:(0018) [00002183] Begin Local Halt Decider Simulation Execution Trace Stored at:1138cc [00002172][001138bc][001138c0] 55 push ebp ; housekeeping [00002173][001138bc][001138c0] 8bec mov ebp,esp ; housekeeping [00002175][001138b8][00002172] 6872210000 push 00002172 ; push DDD [0000217a][001138b4][0000217f] e853f4ffff call 000015d2 ; call HHH(DDD) New slave_stack at:14e2ec [00002172][0015e2e4][0015e2e8] 55 push ebp ; housekeeping [00002173][0015e2e4][0015e2e8] 8bec mov ebp,esp ; housekeeping [00002175][0015e2e0][00002172] 6872210000 push 00002172 ; push DDD [0000217a][0015e2dc][0000217f] e853f4ffff call 000015d2 ; call HHH(DDD) Local Halt Decider: Infinite Recursion Detected Simulation Stopped -- Copyright 2024 Olcott "Talent hits a target no one else can hit; Genius hits a target no one else can see." Arthur Schopenhauer