Bryan Olson schrieb: >> Still think there is no such thing? > > Uh, yes. > > The Cartesian product of two sets A and B (also called the > product set, set direct product, or cross product) is defined to > be the set of [...] > > All sets, no strings. What were you looking at?
Not only sets. This goes on (anyway "everything is a set"). You can also have the Cartesian product of functions. And you can think of a string as a function from a countable index set I to the set of all characters C. So the Cartesian product of two strings will become a function from IxI to CxC. Since IxX is countable again, this is equivalent to a tuple of 2-tuples of characters which you can also interpret as a tuple of strings with 2 chars: "ab" x "cd" = ("ac", "ad", "bc", "bd") Do I have eliminated all remaining clarities now? :-) -- Christoph -- http://mail.python.org/mailman/listinfo/python-list