intros p H'.
replace (Fulp p) with (powerRZ radix (Fexp p)).
2: unfold Fulp in |- *; replace (Fnormalize radix b precision p) with p; auto;
apply sym_equal; apply FcanonicUnique with (3 := pGivesBound);
auto with arith; apply FnormalizeCanonic || apply FnormalizeCorrect;
auto with float zarith.
2: apply FcanonicBound with (1 := H'); auto with float zarith.
unfold FtoRradix in |- *; rewrite <- Fminus_correct; auto with zarith.
case (Z_eq_dec (Fnum p) (- nNormMin radix precision)); intros H1'.
case (Z_eq_dec (Fexp p) (- dExp b)); intros H2'.
rewrite FSuccDiff2; auto with arith.
unfold FtoR in |- *; simpl in |- *; rewrite Rmult_1_l; auto with real.
rewrite FSuccDiff3; auto with arith.
unfold FtoR in |- *; simpl in |- *; rewrite Rmult_1_l.
apply Rlt_le; apply Rlt_powerRZ; auto with real zarith.
unfold Zpred in |- *; auto with zarith.
rewrite FSuccDiff1; auto with arith.
unfold FtoR in |- *; simpl in |- *; rewrite Rmult_1_l; auto with real.
Qed.

Theorem FulpSuc :
forall p : float,
Fbounded b p -> (FNSucc b radix precision p - p <= Fulp p)%R.