intros r p H' H'0 H'1.
rewrite <- (Ropp_involutive r).
rewrite <- (Fopp_Fopp p).
apply MinOppMax.
apply MinBinade; auto with real float.
unfold FtoRradix in |- *; rewrite Fopp_correct; auto with real.
(* Same for max *)
rewrite <- (Fopp_Fopp (FNSucc b radix precision (Fopp p))).
rewrite <- FNPredFopFNSucc; auto.
unfold FtoRradix in |- *; rewrite Fopp_correct; auto with real arith.
Qed.

Theorem MaxMin :
forall (p : float) (r : R),
isMax r p -> r <> p :>R -> isMin r (FNPred b radix precision p).