Section suc.
Variable b : Fbound.
Variable radix : Z.
Variable precision : nat.
Let FtoRradix := FtoR radix.
Local Coercion FtoRradix : float >-> R.
Hypothesis radixMoreThanOne : (1 < radix)%Z.
Let radixMoreThanZERO := Zlt_1_O _ (Zlt_le_weak _ _ radixMoreThanOne).
Hint Resolve radixMoreThanZERO: zarith.
Hypothesis precisionNotZero : precision <> 0.
Hypothesis pGivesBound : Zpos (vNum b) = Zpower_nat radix precision.
Definition FSucc (x : float) :=
match Z_eq_bool (Fnum x) (pPred (vNum b)) with
| true => Float (nNormMin radix precision) (Z.succ (Fexp x))
| false =>
match Z_eq_bool (Fnum x) (- nNormMin radix precision) with
| true =>
match Z_eq_bool (Fexp x) (- dExp b) with
| true => Float (Z.succ (Fnum x)) (Fexp x)
| false => Float (- pPred (vNum b)) (Z.pred (Fexp x))
end
| false => Float (Z.succ (Fnum x)) (Fexp x)
end
end.
intros x H'; 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'0; Contradict H'0; auto.
Qed.

Theorem FSuccSimpl2 :
forall x : float,
Fnum x = (- nNormMin radix precision)%Z ->
Fexp x <> (- dExp b)%Z ->
FSucc x = Float (- pPred (vNum b)) (Z.pred (Fexp x)).