(* IDEM: USED IN between_expf_L0_2:*)

Lemma cF_L0_2:forall (m:fmap)(x y z:dart),
inv_hmap (L m zero x y) ->
let y_0_1 := cF m y in
let x0 := cA m zero x in
betweenf m y_0_1 z x0 ->
cF (L m zero x y) z =
if eq_dart_dec x0 z then y_0_1 else cF m z.