Luke Palmer wrote:
On Dec 5, 2007 11:56 AM, Andrew Coppin <[EMAIL PROTECTED]> wrote:
I was merely noting that questions of the form "is X decidable?" are
usually undecidable. (It's as if God himself wants to tease us...)
I take issue with your definition of "usually" then.
Whenever "X is decidable" is undecidable, "'X is decidable' is decidable' is
decidable, namely false. So there are at least as many decidable sentences
of the form "X is decidable" as there are undecidable ones.
Ouch... my head hurts.
OK, well how about I rephrase it as "most 'interesting' questions about
decidability tend to be undecidable" and we call it quits? ;-)
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