recognizer for empty lists
Major Section:  PROGRAMMING

In the ACL2 logic, (endp x) is the same as (atom x). See atom.

Unlike atom, the guard for endp requires that x is a cons pair or is nil. Thus, endp is typically used as a termination test for functions that recur on a true-listp argument. See guard for general information about guards.

Endp is a Common Lisp function. See any Common Lisp documentation for more information.