proposition: Lemma well_defined_eval: forall (b:quotient S) (f g:quotient S->C), eq_fn f g -> eval b f = eval b g.
proof: Proof. intros. unfold eval. apply H. Qed.
imports: Ensembles EnsemblesImplicit Image ImageImplicit Relation_Definitions Relation_Definitions_Implicit Description ProofIrrelevance EnsemblesSpec