Doc needs help
Fails of List is the empty list.
Fails if List is the empty list.
This needs either a throw or a fix
This is not good (well, it it if you want to use random_member/2 to generate a stream of random booleans, but I think that's taking nondeterminism too far):
?- random_member(1,[1,2,3]). false. ?- random_member(1,[1,2,3]). true.
random_member(1,[1,2,3]) should succeed because 1 is, if not a "random" member, then at least a member of