Dear Hans, Bret and Friends, I submit this paper by S. Wolfram on intractability and undecidability that you all might find of interest:

http://www.stephenwolfram.com/publications/articles/physics/85-undecidabilit y/2/text.html Please note the part that discusses "coordinate reparametrizations" between finitely specified 4-manifolds ... ;-) Kindest regards, Stephen ----- Original Message ----- From: "Hans Moravec" <[EMAIL PROTECTED]> To: "Brent Meeker" <[EMAIL PROTECTED]>; "Everything-list" <[EMAIL PROTECTED]> Cc: "Hans Moravec" <[EMAIL PROTECTED]> Sent: Monday, December 30, 2002 9:39 PM Subject: Re: Quantum Probability and Decision Theory > Brent Meeker: > > It seems [factoring] has been proven recently to be in P: > > http://crypto.cs.mcgill.ca/~stiglic/PRIMES_P_FAQ.html#PRIMES > > No, that's primality testing, which has always been > much easier than factoring. > >