# Intersectp

`(intersectp x y)` checks whether X and Y have any common
members.

Logically we just check whether the intersect of X and
Y is emptyp.

In the execution, we use a faster function that checks for any common
members and doesn't build any new sets.

### Definitions and Theorems

**Function: **intersectp

(defun intersectp (x y)
(declare (xargs :guard (and (setp x) (setp y))))
(mbe :logic (not (emptyp (intersect x y)))
:exec (fast-intersectp x y)))