>> 3. Of what practical use (or even esoteric academic interest) is the >> parity of the number of interchanges?
>I presume the goal is academic, determining whether a >permutation is a member of >the alternating group of even permutations (A4, A5, ...). For >some problems, >that is a useful invariant. For instance, iirc, the parity >determines whether a >given 15 puzzle arrangement is solvable. To tell whether a wave function corresponds to bosons or fermions. -- http://mail.python.org/mailman/listinfo/python-list
