Completeness theorem for parse-dec-val.
Theorem:
(defthm parse-dec-val-when-tree-match (implies (and (tree-match-element-p tree (element-rulename *dec-val*) *grammar*) (tree-terminatedp tree) (mv-nth 0 (parse-digit rest-input)) (mv-nth 0 (parse-ichar #\. rest-input)) (mv-nth 0 (parse-ichar #\- rest-input))) (equal (parse-dec-val (append (tree->string tree) rest-input)) (mv nil (tree-fix tree) (nat-list-fix rest-input)))))