The natural reading of 'greatest' is, of course, the greatest in the divisibility preorder (it's partial order on natural numbers but only a preorder on integers). Thus, gcd 0 0 = 0.
3 and -3 are equivalent in that preoder. Thus, an additional comment may be in order. Stefan _______________________________________________ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
