> s0 = set([1]) > s1 = set([1,2]) > s2 = set([2]) > S = set([s0,s1,s2]) > one answer we're searching for is s0 = s1 - s2 > > There may be arbitrarily many set elements (denoted by integers > 1,2,3,...) and arbitrarily many combinations of the elements composing > the sets s_i (s0, s1, ...). We can use any operation or function which > takes and returns sets.
In that case, there is always a trivial answer. As I can use any function which takes and returns sets, and as I shall come up with a function that returns s0, I just use the following function def f(s): return s0 To compute s0, just invoke f with any other of the sets, and you will - get s0. > I think this problem is related to integer partitioning, but it's not > quite the same. I think the problem is significantly underspecified. It would be a more interesting problem if there was a restriction to a few selected set operations, e.g. union, intersection, difference, and combinations thereof. Regards, Martin -- http://mail.python.org/mailman/listinfo/python-list
