Check if the unary minus of a value of type
Function:
(defun minus-ushort-okp (x) (declare (xargs :guard (and (ushortp x)))) (minus-sint-okp (sint-from-ushort x)))
Theorem:
(defthm booleanp-of-minus-ushort-okp (booleanp (minus-ushort-okp x)))
Theorem:
(defthm minus-ushort-okp-of-ushort-fix-x (equal (minus-ushort-okp (ushort-fix x)) (minus-ushort-okp x)))
Theorem:
(defthm minus-ushort-okp-ushort-equiv-congruence-on-x (implies (ushort-equiv x x-equiv) (equal (minus-ushort-okp x) (minus-ushort-okp x-equiv))) :rule-classes :congruence)