this variable was mislabeled
fix require_tmp and add sets_union and sets_intrsctn
found a better way
enforce two or more input sets since one makes no sense
optimize in the most common case, should produce identical result
add sets_sym_diff function
i like this way better
i like this way better
sets_sym_diff needs exactly two sets
make these a bit safer to use
fix require_tmp
refactor currently testing