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