proposition: Theorem Fneg_correct : forall beta (f : float beta), FtoX (Fneg f) = Xneg (FtoX f).
proof: Proof. intros. case f ; intros. apply refl_equal. simpl. rewrite Ropp_0. apply refl_equal. simpl. rewrite FtoR_neg. apply refl_equal. Qed.
imports: Coq(Reals Bool ZArith Psatz) Flocq(Core Digits Bracket Round Operations) mathcomp.ssreflect(ssrbool) Stdlib Xreal Basic Generic