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Representation-of-integer-operations

Minus-ushort

Unary minus of a value of type unsigned short [C:6.5.3].

Definitions and Theorems

Function: minus-ushort

(defun minus-ushort (x)
  (declare (xargs :guard (and (ushortp x) (minus-ushort-okp x))))
  (minus-sint (sint-from-ushort x)))

Theorem: sintp-of-minus-ushort

(defthm sintp-of-minus-ushort
  (sintp (minus-ushort x)))

Theorem: minus-ushort-of-ushort-fix-x

(defthm minus-ushort-of-ushort-fix-x
  (equal (minus-ushort (ushort-fix x))
         (minus-ushort x)))

Theorem: minus-ushort-ushort-equiv-congruence-on-x

(defthm minus-ushort-ushort-equiv-congruence-on-x
  (implies (ushort-equiv x x-equiv)
           (equal (minus-ushort x)
                  (minus-ushort x-equiv)))
  :rule-classes :congruence)