Programming challenge: wildcard exclusion in cartesian products

[wkehowski at cox.net]

The point is to submit elegant code that showcases the features of each
language. And the problem is, just to clarify, given a set WC of
wildcards in any logical combination, and if WC(S^n) is the set all s
in S^n that matches the wildcards, then efficiently generate the
complement S^n\WC(S^n). You are free to restate the problem in any
equivalent way.