Proof using.
intros.
find_eapply_lem_hyp execute_log'_trace;
rewrite app_nil_r in *; eauto.
Qed.

(* FIXME: move to StructTact *)
Lemma hd_error_Some_app :
forall A l l' (x : A),
hd_error l = Some x ->
hd_error (l ++ l') = Some x.