intros x H' H'0; unfold FSucc in |- *.
generalize (Z_eq_bool_correct (Fnum x) (pPred (vNum b)));
case (Z_eq_bool (Fnum x) (pPred (vNum b))); auto.
intros H'1; absurd (0%nat <= pPred (vNum b))%Z; auto with zarith arith.
rewrite <- H'1; rewrite H'.
unfold nNormMin in |- *; simpl in |- *; auto with zarith.
replace 0%Z with (- (0))%Z; auto with zarith.
unfold pPred in |- *; apply Zle_Zpred; auto with zarith.
intros H'1;
generalize (Z_eq_bool_correct (Fnum x) (- nNormMin radix precision));
case (Z_eq_bool (Fnum x) (- nNormMin radix precision)).
intros H'2; generalize (Z_eq_bool_correct (Fexp x) (- dExp b));
case (Z_eq_bool (Fexp x) (- dExp b)); auto.
intros H'3; Contradict H'0; auto.
intros H'2; Contradict H'2; auto.
Qed.

Theorem FSuccSimpl3 :
FSucc (Float (- nNormMin radix precision) (- dExp b)) =
Float (Zsucc (- nNormMin radix precision)) (- dExp b).