(*========================================================== ============================================================ TOPOLOGICAL FMAPS, HMAPS -  WITH TAGS AND EMBEDDINGS  PART 8:  nf_L0L1 (PART 1)  COMPLETE ============================================================ ==========================================================*)
Require Export Jordan7.
(*========================================================== nf_L0L1 (PART 1) ===========================================================*)
(* OK!: *)
Open Scope nat_scope.
(* OK, AVEC LE LEMME CI-DESSUS A LA FIN : *)
Open Scope nat_scope.

Lemma nf_L0L1_I:forall (m:fmap)(x y x' y':dart),
let m1:=L (L m zero x y) one x' y' in
let m2:=L (L m one x' y') zero x y in
inv_hmap m1 ->
let x_1 := cA_1 m one x in
let y_0 := cA_1 m zero y in
let y'0 := cA m zero y' in
let x'1 := cA m one x' in
let y'0b := cA (L m zero x y) zero y' in
let x_1b := cA_1 (L m one x' y') one x in
expf m x_1 y ->
expf m x' y'0 ->
expf (L m zero x y) x' y'0b ->
~ expf (L m one x' y') x_1b y ->
False.