Check if a value of type
Function:
(defun boolean-from-slong (x) (declare (xargs :guard (and (slongp x)))) (/= (integer-from-slong x) 0))
Theorem:
(defthm booleanp-of-boolean-from-slong (booleanp (boolean-from-slong x)))
Theorem:
(defthm boolean-from-slong-of-slong-fix-x (equal (boolean-from-slong (slong-fix x)) (boolean-from-slong x)))
Theorem:
(defthm boolean-from-slong-slong-equiv-congruence-on-x (implies (slong-equiv x x-equiv) (equal (boolean-from-slong x) (boolean-from-slong x-equiv))) :rule-classes :congruence)