31 Dec
2011
31 Dec
'11
2:23 a.m.
On Fri, Dec 30, 2011 at 05:53:26PM -0500, Robert Weisser wrote:
stumped. I don't see how any function can see inside the set. I don't know enough Haskell to be certain, but it looks impossible to me. Is there something I am missing?
Nope, you're absolutely right. This is one of the big differences between an "intensional" representation of a set (such as a list) which lets you inspect the set's internal structure, and an "extensional" representation (like a -> Bool) which only lets you inspect the set's "behavior". You may enjoy trying to think of other differences (hint: think about efficiency). -Brent