(* THEN, BY expf_dec: IMPORTANT RESULT *)

Theorem expf_not_expf_L0: forall (m:fmap)(x y:dart),
inv_hmap (L m zero x y) ->
let x_1:= cA_1 m one x in
let x0 := cA m zero x in
(expf m x_1 y <->
~expf (L m zero x y) y x0).