- add_nb_set(+Key, !Set) is det
- add_nb_set(+Key, !Set, ?New) is semidet
- Insert Key into the set. If a variant (see =@=/2) of Key is
already in the set, the set is unchanged and New is unified with
false. Otherwise, New is unified with true and a copy of
Key is added to the set.
- To be done
- - Computing the hash for cyclic terms is performed with
the help of term_factorized/3, which performs rather
poorly.