intros x; elim x; auto.
intros y z H'; inversion_clear H'.
intros H'0; inversion_clear H'0; auto.
intros a l H' y z H'0; inversion_clear H'0.
intros H4; inversion_clear H4.
change (eqP (pX a l) (pX mb0 q0)) in |- *; apply eqpP1; eauto.
apply (eqTerm_trans _ _ _ _ _ _ _ _ _ cs n) with (y := mb); auto.
Qed.
Hint Resolve eqp_refl.
Let eqTerm_imp_eqT := eqTerm_imp_eqT A eqA n.

Theorem ltP_refl_pX :
forall (a : Term A n) (p : list (Term A n)),
canonical A0 eqA ltM (pX a p) -> ltP (A:=A) (n:=n) ltM p (pX a p).