Module InternSets

Given a binary predicate getAValue, this module groups the Value column by Key and constructs the corresponding sets of Values as single entities.

The output is a functional predicate, getSet, such that getSet(k).contains(v) is equivalent to v = getAValue(k), and a class, Set, that canonically represents a set of Values. In particular, if two keys k1 and k2 relate to the same set of values, then getSet(k1) = getSet(k2).