fact: Example ab_star_parses_abab : parse_of_grammar "abab"%string ab_star_grammar.
imports: Coq.Strings.String Coq.Strings.Ascii Coq.Lists.List Fiat.Parsers.ContextFreeGrammar.Core Fiat.Parsers.ContextFreeGrammar.Notations Fiat.Parsers.StringLike.String Fiat.Parsers.Grammars.ABStar Fiat.Parsers.Grammars.ExpressionNumPlusParen Fiat.Parsers.Grammars.ExpressionParen Fiat.Parsers.Grammars.StringLiteral Fiat.Parsers.Grammars.JSComment