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• Std/basic
• Maybe-stringp

Maybe-string-fix

Fixer for maybe-stringp.

Signature

(maybe-string-fix x) → fixed-x

Arguments

x — Guard (maybe-stringp x).

Returns

fixed-x — Type (maybe-stringp fixed-x).

Definitions and Theorems

Function: maybe-string-fix

(defun maybe-string-fix (x)
  (declare (xargs :guard (maybe-stringp x)))
  (mbe :logic (if (maybe-stringp x) x nil)
       :exec x))

Theorem: maybe-stringp-of-maybe-string-fix

(defthm maybe-stringp-of-maybe-string-fix
  (b* ((fixed-x (maybe-string-fix x)))
    (maybe-stringp fixed-x))
  :rule-classes :rewrite)

Theorem: maybe-string-fix-when-maybe-stringp

(defthm maybe-string-fix-when-maybe-stringp
  (implies (maybe-stringp x)
           (equal (maybe-string-fix x) x)))