Tree matching theorem for parse-equal-/-equal-slash.
Theorem:
(defthm tree-match-of-parse-equal-/-equal-slash (b* (((mv error? tree? &) (parse-equal-/-equal-slash input))) (implies (and (not error?) (equal element (!_ (/_ "=") (/_ "=/")))) (tree-match-element-p tree? element *grammar*))))