Isn't the state-space of similar such problems known to exceed the number of atoms in the Universe? There is a term for problems which are rendered unsolvable because there just isn't enough possible state-storing matter to represent them, but I can't think of it now.

Pardon me if this is a stupid question, my experience with AI is limited. Funny Eliezer should mention Haskell, I've got to get back to trying to wrap my brain around 'monads'.