oset.pl -- Ordered set manipulation

This library defines set operations on sets represented as ordered lists.

oset_is(+OSet): check that OSet in correct format (standard order)
oset_union(+OSet1, +OSet2, -Union)
oset_int(+OSet1, +OSet2, -Int): ordered set intersection
oset_diff(+InOSet, +NotInOSet, -Diff): ordered set difference
oset_dunion(+SetofSets, -DUnion): distributed union
oset_dint(+SetofSets, -DInt): distributed intersection
oset_power(+Set, -PSet): True when PSet is the powerset of Set. That is, Pset is a set of all subsets of Set, where each subset is a proper ordered set.
oset_addel(+Set, +El, -Add): ordered set element addition
oset_delel(+Set, +El, -Del): ordered set element deletion