9/23    Anyone know how to count the nubmer of possible interleavings
        of two sets of N objects?
        \_ if by interleaving, you mean placing them in a line in any
           order, then the answer is easy it's (N+M)!
           if you mean elements of set 1 have to be adjacent to elements
           of set 2, then the answer is also easy: N!M!2. i think. -ali
           \_ Ok, I guess that was a bad statement of the problem. I think
              the best example of what I'm trying to say is: take 4 fingers
              on each hand; interleave them in all possible ways preserving
              the order on each hand but nothing else.
              \_ C(2N,N) (i.e. ((2N)!)/(N!^2)). -alexf