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Integer-operations

Int-minus

Arithmetic negation of signed integer values.

Signature
(int-minus operand) → result
Arguments: operand — Guard (intp operand).
Returns: result — Type (intp result).

Definitions and Theorems

Function: int-minus

(defun int-minus (operand)
  (declare (xargs :guard (intp operand)))
  (b* ((size (int->size operand))
       (x (int->value operand)))
    (make-int :size (int->size operand)
              :value (logext size (- x)))))

Theorem: intp-of-int-minus

(defthm intp-of-int-minus
  (b* ((result (int-minus operand)))
    (intp result))
  :rule-classes :rewrite)

Theorem: int-minus-of-int-fix-operand

(defthm int-minus-of-int-fix-operand
  (equal (int-minus (int-fix operand))
         (int-minus operand)))

Theorem: int-minus-int-equiv-congruence-on-operand

(defthm int-minus-int-equiv-congruence-on-operand
  (implies (int-equiv operand operand-equiv)
           (equal (int-minus operand)
                  (int-minus operand-equiv)))
  :rule-classes :congruence)