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