fact: Definition injective_ens : Prop := forall x0 x1 : A, In U x0 -> In U x1 -> f x0 = f x1 -> x0 = x1.
imports: Coq(ClassicalChoice Description Program.Subset) ZornsLemma(DecidableDec EnsemblesImplicit Families FunctionProperties Image InverseImage Powerset_facts Proj1SigInjective) Coq(RelationClasses)