proposition: Lemma some_invalid_nonterminal_invalid' : ~List.In some_invalid_nonterminal valid_nonterminals.
proof: Proof. apply gensym_fresh. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.ZArith.ZArith Fiat.Common.Enumerable Fiat.Common.Enumerable.BoolProp Fiat.Common.List.Operations Fiat.Common.List.ListFacts Fiat.Common.Equality Fiat.Parsers.ContextFreeGrammar.Core Fiat.Parsers.ContextFreeGrammar.PreNotations Fiat.Common.Gensym Fiat.Common.Tactics.BreakMatch Fiat.Common.Tactics.DestructHead