proposition: Lemma Rle_le_eq : forall r1 r2, r1 <= r2 /\ r2 <= r1 <-> r1 = r2.
proof: Proof. intros r1 r2; split. - now intros [H1 H2]; apply Rle_antisym. - now intros ->; split; apply Rle_refl. Qed.
imports: RelationClasses Raxioms Rpow_def ZArith ZArithRing RealField