Generates a set with A size in the indicated range using the given Gen lt - a predicate function that returns true if l is lexically less than r eq - a predicate function that returns true if l is equal to r Note that the returned set may not meet the minimum size requirement after de-duplication.

The efficiency of this algorithm is O(N).

Returns the intersection of set 'a' and 'b' The efficiency of this algorithm is O(5 * N).

Returns the set 'a' minus set 'b' The efficiency of this algorithm is O(N).

Returns the set union of set 'a' and 'b'.

Makes a "real" set from an array.