(* THEN, WE SYMMETRICALLY HAVE: *)

Lemma between_expf_B0_2:forall (m:fmap)(x:dart)(i:nat),
inv_hmap m -> succ m zero x ->
let x0 := cA m zero x in
let x_1:= cA_1 m one x in
let xb0:= bottom m zero x in
let xh0:= top m zero x in
let xh0_1:= cA_1 m one xh0 in
let p:= MF.Iter_upb m xh0_1 in
let z:= Iter (cF m) i xh0_1 in
~expf m x0 xb0 ->
(i < p)%nat ->
expf (B m zero x) xh0_1 z.