Inductive match_code: code -> code -> Prop :=
| match_code_nil:
match_code nil nil
| match_code_cons: forall i before after c c',
match_code c c' ->
match_code (i :: c) (i :: add_delta_ranges before after c').
Remark diff_same:
forall s, diff s s = nil.
Remark delta_state_same:
forall s, delta_state s s = (nil, nil).

Lemma transf_code_match:
forall lm c before, match_code c (transf_code lm before c).