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Floating-point-operations

Double-plus

Unary plus + on doubles [JLS14:4.2.4] [JLS14:15.15.3].

Signature
(double-plus operand) → result
Arguments: operand — Guard (double-valuep operand).
Returns: result — Type (double-valuep result).

Definitions and Theorems

Function: double-plus

(defun double-plus (operand)
  (declare (xargs :guard (double-valuep operand)))
  (b* ((x (double-value->double operand)))
    (double-value (double-plus-abs x))))

Theorem: double-valuep-of-double-plus

(defthm double-valuep-of-double-plus
  (b* ((result (double-plus operand)))
    (double-valuep result))
  :rule-classes :rewrite)

Theorem: double-plus-of-double-value-fix-operand

(defthm double-plus-of-double-value-fix-operand
  (equal (double-plus (double-value-fix operand))
         (double-plus operand)))

Theorem: double-plus-double-value-equiv-congruence-on-operand

(defthm double-plus-double-value-equiv-congruence-on-operand
  (implies (double-value-equiv operand operand-equiv)
           (equal (double-plus operand)
                  (double-plus operand-equiv)))
  :rule-classes :congruence)