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Maybe-string

Fixtype of optional strings.

The recognizer is maybe-stringp and the fixer is maybe-string-fix.

Definitions and Theorems

Function: maybe-string-equiv$inline

(defun maybe-string-equiv$inline (x y)
       (declare (xargs :guard (and (maybe-stringp x)
                                   (maybe-stringp y))))
       (equal (maybe-string-fix x)
              (maybe-string-fix y)))

Theorem: maybe-string-equiv-is-an-equivalence

(defthm maybe-string-equiv-is-an-equivalence
        (and (booleanp (maybe-string-equiv x y))
             (maybe-string-equiv x x)
             (implies (maybe-string-equiv x y)
                      (maybe-string-equiv y x))
             (implies (and (maybe-string-equiv x y)
                           (maybe-string-equiv y z))
                      (maybe-string-equiv x z)))
        :rule-classes (:equivalence))

Theorem: maybe-string-equiv-implies-equal-maybe-string-fix-1

(defthm maybe-string-equiv-implies-equal-maybe-string-fix-1
        (implies (maybe-string-equiv x x-equiv)
                 (equal (maybe-string-fix x)
                        (maybe-string-fix x-equiv)))
        :rule-classes (:congruence))

Theorem: maybe-string-fix-under-maybe-string-equiv

(defthm maybe-string-fix-under-maybe-string-equiv
        (maybe-string-equiv (maybe-string-fix x)
                            x)
        :rule-classes (:rewrite :rewrite-quoted-constant))

Theorem: equal-of-maybe-string-fix-1-forward-to-maybe-string-equiv

(defthm equal-of-maybe-string-fix-1-forward-to-maybe-string-equiv
        (implies (equal (maybe-string-fix x) y)
                 (maybe-string-equiv x y))
        :rule-classes :forward-chaining)

Theorem: equal-of-maybe-string-fix-2-forward-to-maybe-string-equiv

(defthm equal-of-maybe-string-fix-2-forward-to-maybe-string-equiv
        (implies (equal x (maybe-string-fix y))
                 (maybe-string-equiv x y))
        :rule-classes :forward-chaining)

Theorem: maybe-string-equiv-of-maybe-string-fix-1-forward

(defthm maybe-string-equiv-of-maybe-string-fix-1-forward
        (implies (maybe-string-equiv (maybe-string-fix x)
                                     y)
                 (maybe-string-equiv x y))
        :rule-classes :forward-chaining)

Theorem: maybe-string-equiv-of-maybe-string-fix-2-forward

(defthm maybe-string-equiv-of-maybe-string-fix-2-forward
        (implies (maybe-string-equiv x (maybe-string-fix y))
                 (maybe-string-equiv x y))
        :rule-classes :forward-chaining)