ABSTRACT
A set is a collection of distinct values treated as a whole. All sets in VDM-SL are finite: each set contains only a finite number of elements.
If T is a flat type, the set type:
T-set
has values which are the finite sets of values of the type T. T can be any flat type (see section 5.8), including a set type; thus -set-set (sets of sets of positive integers) and char+ -set (sets of non-empty character strings) are both valid types.
