Parsing failure propagation from ("." 1*DIGIT) to 1*("." 1*DIGIT).
Theorem: fail-1*-dot-1*digit-when-fail-dot-1*digit
(defthm fail-1*-dot-1*digit-when-fail-dot-1*digit (implies (mv-nth 0 (parse-dot-1*digit input)) (mv-nth 0 (parse-1*-dot-1*digit input))))