Path: ...!feeds.phibee-telecom.net!3.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Mikko Newsgroups: comp.theory Subject: Re: Liar detector: Fred, Richard, Joes and Alan --- Ben's agreement Date: Fri, 19 Jul 2024 11:51:33 +0300 Organization: - Lines: 59 Message-ID: References: <60a1c2490e9bd9a5478fd173a20ed64d5eb158f9@i2pn2.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 19 Jul 2024 10:51:33 +0200 (CEST) Injection-Info: dont-email.me; posting-host="f38904cb6ada6338ee5486d51c69675b"; logging-data="3073212"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/teFH/GjyVghcve+msK7V+" User-Agent: Unison/2.2 Cancel-Lock: sha1:PcAI6MvVzba7R8nb+gQP+lPlgUs= Bytes: 4251 On 2024-07-18 13:17:22 +0000, olcott said: > On 7/18/2024 2:40 AM, Mikko wrote: >> On 2024-07-17 13:00:55 +0000, olcott said: >> >>> On 7/17/2024 1:43 AM, Mikko wrote: >>>> On 2024-07-16 14:21:28 +0000, olcott said: >>>>> >>>>> When simulated input DDD stops running {if and only if} >>>>> the simulation of this input DDD has been aborted this >>>>> necessitates that input DDD specifies non-halting behavior >>>> >>>> DDD does not stop runnig unless it is completely exeuted. >>> >>> _DDD() >>> [00002163] 55         push ebp      ; housekeeping >>> [00002164] 8bec       mov ebp,esp   ; housekeeping >>> [00002166] 6863210000 push 00002163 ; push DDD >>> [0000216b] e853f4ffff call 000015c3 ; call HHH(DDD) >>> [00002170] 83c404     add esp,+04 >>> [00002173] 5d         pop ebp >>> [00002174] c3         ret >>> Size in bytes:(0018) [00002174] >>> >>> DDD emulated by HHH according to the semantic meaning of >>> its x86 instructions never stop running unless aborted. >> >> You mean HHH's simulation of DDD may not termite before HHH aborts it? > > When we examine the infinite set of every HHH/DDD pair such that: > HHH₁ one step of DDD₁ is correctly emulated by HHH₁. > HHH₂ two steps of DDD₂ are correctly emulated by HHH₂. > HHH₃ three steps of DDD₃ are correctly emulated by HHH₃. > ... > HHH∞ The emulation of DDD∞ by HHH∞ never stops running. > > When each DDD of the HHH/DDD pairs above is correctly emulated > by its corresponding HHH according to the semantic meaning of its > x86 instructions it CANNOT POSSIBLY reach past its own machine > address 0000216b, not even by an act of God. You apparently mean that no HHHᵢ can simulate the corresponding DDDᵢ to its termination? For every finite i the behaviour specified by DDDᵢ is halting. >> The behaviour specified by DDD, both by C semantics and by x86 semantics, >> is halting if HHH returns. Otherwise HHH is not a decider. > > When HHH is required to be a pure function then only one element > of the above infinite set of every possible HHH/DDD is not a decider. The behavour of DDDᵢ depends on what HHHᵢ does. Wheter HHHᵢ is required to what it does has no evvect on the behaviour of DDDᵢ. A pair is never a decider. -- Mikko