The powerset(s) calling sequence constructs the power set of a set, list, or non-negative integer.

If s is a set, then powerset command returns the power set of s, that is, a set consisting of all the subsets of s.  The power set has  entries, where  is the number of elements in s.

If s is a non-negative integer, powerset interprets it as a set of the first s integers.

If s is a list, powerset returns a list of all the sublists of s.  The number of sublists depends on the multiplicities of s.

To iterate through the subsets of a given set without generating all subsets beforehand, use combinat[subsets].