4 Aug
2009
4 Aug
'09
4:57 p.m.
Your function is not equivalent:
perm _|_ = _|_
permutations _|_ = _|_ : _|_
I have a vague memory that the library version diagonalises properly, so that if you give it a lazy infinite input, it still generates sensible output lazily. If so, this important property should be noted in the haddocks. Regards, Malcolm