Path: ...!2.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: immibis <news@immibis.com>
Newsgroups: comp.theory
Subject: Re: Proving my 2004 claim that some decider/input pairs are incorrect
 questions (NFFC)
Date: Wed, 13 Mar 2024 05:00:05 +0100
Organization: A noiseless patient Spider
Lines: 29
Message-ID: <usr8c5$p107$3@dont-email.me>
References: <usda7b$18hee$1@dont-email.me> <use1sh$1gd96$2@dont-email.me>
 <use37h$15q45$3@i2pn2.org> <use4f1$1grfn$1@dont-email.me>
 <8634t1nx2p.fsf@yaxley.in> <usfase$1p1t5$1@dont-email.me>
 <usfd8m$1p8cg$4@dont-email.me> <ush8rt$288t1$1@dont-email.me>
 <usi0ej$2d0oc$2@dont-email.me> <usk8s1$2v4mk$1@dont-email.me>
 <uskg40$30hr1$2@dont-email.me> <usmk7t$3hvpu$1@dont-email.me>
 <usn4k9$3li08$1@dont-email.me> <usn7b3$3m7lb$1@dont-email.me>
 <usn89c$3m7k2$4@dont-email.me> <usp4u1$6nok$1@dont-email.me>
 <uspnac$aqak$1@dont-email.me> <usq00t$1l201$4@i2pn2.org>
 <usq0ru$caqa$11@dont-email.me> <usq6sc$ed9g$2@dont-email.me>
 <usq7n8$e4sh$6@dont-email.me> <usqdkp$fsqm$1@dont-email.me>
 <usqe55$g2eo$2@dont-email.me> <usql24$1m5uu$1@i2pn2.org>
 <usqlo0$hn98$3@dont-email.me> <usqn03$1m5ut$4@i2pn2.org>
 <usqor4$id9c$2@dont-email.me> <usqtpi$1mf1r$2@i2pn2.org>
 <usr0sm$js25$1@dont-email.me> <usr2dd$k5kt$2@dont-email.me>
 <usr3ml$kdfp$1@dont-email.me> <usr5u4$1mk0g$6@i2pn2.org>
 <usr6al$oipj$3@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Wed, 13 Mar 2024 04:00:05 -0000 (UTC)
Injection-Info: dont-email.me; posting-host="d3f75eaadad991e96f7897dd49a5bb0b";
	logging-data="820231"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/++D8bQLx+03IQUWXcS6Ka"
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:9Tzp8L2m8yDKJxBRJUe8mBML1xo=
In-Reply-To: <usr6al$oipj$3@dont-email.me>
Content-Language: en-US
Bytes: 3153

On 13/03/24 04:25, olcott wrote:
>> H COULD halt in a state other than qy or qn and thus make itself wrong.
>>
> No it is not wrong. It is the same as a divide by zero exception.

Is "divide by zero exception" the correct answer to "does this machine 
halt?"?

>> This might be a reasonable extension for a decider, Accept, Reject, 
>> and an "I can't tell". The key is to somehow limit where "I can't 
>> tell" can be used, or it makes the decider useless.
>>
> If it can be limited then it can be limited for H(D,D)
> otherwise when some machine can do it then it can be done.

I don't think you understood what Richard said.

>> Could be a LOT better (but still not meet the original requrements) 
>> then lying by going to Accept or Reject incorrectly.
>>
>> This was actually discussed as an option a while back
> 
> This time you understand how H(D,D) and H1(D,D) work instead
> of simply denying that they do what they did do.

Halting semi-deciders that sometimes output "I can't tell" can still be 
very useful practical tools, however, they do not disprove the halting 
theorem.