Disambiguation between rule and (*c-wsp c-nl).
Theorem: fail-rule-when-match-*cwsp-cnl
(defthm fail-rule-when-match-*cwsp-cnl (implies (and (tree-match-element-p tree (!_ (/_ (*_ *c-wsp*) *c-nl*)) *grammar*) (tree-terminatedp tree)) (mv-nth 0 (parse-rule (append (tree->string tree) rest-input)))))