Undocumented predicates
The following predicates are exported, but not or incorrectly documented.
- pset_empty(Arg1)
- list_set(Arg1, Arg2)
- set_list(Arg1, Arg2)
- subset_t(Arg1, Arg2, Arg3)
- punion(Arg1, Arg2, Arg3)
- pdifference(Arg1, Arg2, Arg3)
- pintersection(Arg1, Arg2, Arg3)