proposition: Theorem Fminus_same_exp : forall m1 m2 e, Fminus (Float m1 e) (Float m2 e) = Float (m1 - m2) e.
proof: Proof. intros m1 m2 e. unfold Fminus. apply Fplus_same_exp. Qed.
imports: Coq(ZArith Reals Lia) Zaux Raux Defs Float_prop