fact: Definition ensemble_least_upper_bound : Ensemble String -> Ensemble String -> Ensemble String := fun P1 P2 => fun str => P1 str \/ P2 str.
imports: Coq.Sets.Ensembles Coq.Classes.Morphisms Fiat.Parsers.ContextFreeGrammar.PreNotations Fiat.Parsers.ContextFreeGrammar.Carriers Fiat.Parsers.ContextFreeGrammar.Core Fiat.Parsers.ContextFreeGrammar.Precompute Fiat.Parsers.BaseTypes Fiat.Parsers.Splitters.RDPList Fiat.Parsers.ContextFreeGrammar.Fix.Definitions Fiat.Common.List.ListMorphisms