fact: Definition mand (p : Parser Toks Tok M A n) (q : Parser Toks Tok M B n) : Parser Toks Tok M (option A * B) n := alt (map (fun v => (Some (fst v), snd v)) (and p q)) (map (fun v => (None, v)) q).
imports: Coq(PeanoNat) parseque(Category Induction Sized NEList Success EqDec)