proposition: Lemma Same_set_Union_Intersection {A} (x y z : Ensemble A) : (x ∪ (y ∩ z)) ≅ (x ∪ y) ∩ (x ∪ z).
proof: Proof. Ensembles_t. Qed.
imports: Fiat.Common.Ensembles.Notations Fiat.Common.Ensembles.Tactics Fiat.Common.Ensembles.Morphisms Fiat.Common