Sets
(set-card S)
returns the cardinality of the set S
(set-contains S e)
is true iff e belongs to S
(set-elementadd S e)
returns the set S union {e}
(set-remove S e)
returns the set S \ {e}
set-emptyset
returns the emptyset
(set-isempty? S)
is true iff the set S is empty
(set-union A B)
returns the union of A and B
(set-singleton e)
returns the set {e}
(set-include? A B)
is true if A is included in B
(set-equal? A B)
is true if A = B