unfold incl in |- *; simpl in |- *; auto.
intros a L1 L2 H' a0 H'0; case H'0;
[ intros H'1; rewrite <- H'1; clear H'0 | intros H'1; clear H'0 ];
auto.
Qed.

(* Specifications: *)
Theorem ObuchPincl :
forall aP R Q : list (poly A0 eqA ltM), OBuch aP Q R -> incl aP R.