(* OK: *)

Lemma not_expf_L1_x_y0:forall (m:fmap)(x y z t:dart),
inv_hmap (L m one x y) -> exd m z ->
let y0 := cA m zero y in
let y_1 := cA_1 m one y in
expf m x y0 -> ~expf (L m one x y) x y_1.