intros x H' H'0; rewrite (FPredFopFSucc x).
pattern x at 1 in |- *; rewrite <- (Fopp_Fopp x).
rewrite <- Fopp_Fminus_dist.
rewrite Fopp_Fminus.
unfold FtoRradix in |- *; rewrite FSuccDiff3; auto.
rewrite <- H'; case x; auto.
Qed.

(* Specifications: *)
Theorem FBoundedPred : forall f : float, Fbounded b f -> Fbounded b (FPred f).
intros f H'; rewrite (FPredFopFSucc f); auto with float.