Re: [PO] halting problem: existence proofs

From: Robert Low (mtx014_at_linux.services.coventry.ac.uk)
Date: 08/30/04 

Date: 30 Aug 2004 07:59:40 GMT

Mitch Harris <harrisq@tcs.inf.tu-dresden.de> wrote:
>Robert Low wrote:
>>>>You have to provide the algorithm first.
>>>Not to refute undecidability I don't.
>> 1/ That's precisely what you have to do it you
>> want to refute the statement that the halting
>> problem is not computable.
>He doesn't -have- to provide an algorithm. There are other

Ach, you're right, of course. A proof of existence doesn't
have to be constructive. (Though they tend to be the most
compelling ones :-))

But my second leg is enough to stand on: if
he's telling people to run his algorithm and
see what happens (which he was) he does need
to provide it. 

-- 
Rob.  http://www.mis.coventry.ac.uk/~mtx014/

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