fact: Definition option_cons {A} : option A -> option (list A) -> option (list A) := fun pit pits => match pit, pits with | Some pit', Some pits' => Some (cons pit' pits') | None, _ => None | _, None => None end.
imports: Coq.Strings.String Fiat.Parsers.GenericBaseTypes Fiat.Parsers.ContextFreeGrammar.Carriers Fiat.Parsers.ContextFreeGrammar.PreNotations