intros P p H'; elim H'; auto.
intros a p0 H P0.
exists (exist (canonical A0 eqA ltM) (a :: p0) H); split; simpl in |- *; auto.
intros a p0 P0 H'0 H'1; elim H'1; intros q E; elim E; intros H'2 H'3;
clear E H'1.
exists q; split; simpl in |- *; auto.
Qed.

Theorem Incl_inp_inPolySet :
forall P Q : list (poly A0 eqA ltM),
incl P Q -> forall p : list (Term A n), inPolySet p P -> inPolySet p Q.