elim H; intros.
elim a; intros.
elim tmp_add_typ with l t; intros; auto.
right.
apply decl_err_not_wf with err; trivial.
elim add_cst with l t t0; intros; auto.
right.
apply decl_err_not_wf with err; trivial.
right; red in |- *; intros.
apply b.
apply inv_wf with a; trivial.
Qed.

Theorem decide_typ : forall (e : env) (t T : term), decide (typ e t T).
intros.