Programming challenge: wildcard exclusion in cartesian products

[wkehowski at cox.net]

Hello,

The solution that would have the most utility would be one where the
elements are generated one-by-one, loop-like, so that they can be used
in the body of a loop, and to avoid the fact that even with exclusion
the cardinality of the target set EX^n could be in the millions even
with a full list of wc's, that is, a list containing at least one wc of
every length in 2..(n-1). I don't know enough Lisp, Haskell or
Qi/Prolog to know if the solutions so far can be modified to do this.
The Python program is too slow for large sets.

Walter Kehowski