fact: Definition pbh_check_level (ch : Char) (start_level : nat) : bool := pb_check_level true ch start_level.
imports: Coq.Strings.String Coq.Lists.List Coq.Classes.RelationPairs Fiat.Parsers.ContextFreeGrammar.Core Fiat.Parsers.BaseTypes Fiat.Parsers.Reachable.ParenBalanced.Core Fiat.Common Fiat.Common.Enumerable