fact: Definition item_valid (it : item Char) := match it with | Terminal _ => True | NonTerminal nt' => is_true (is_valid_nonterminal initial_nonterminals_data (of_nonterminal nt')) end.
imports: Fiat.Parsers.StringLike.Core Fiat.Parsers.ContextFreeGrammar.Core Fiat.Parsers.BaseTypes