intros a b p q s Eqd Z0 H'; inversion_clear H'.
absurd (ltT ltM b a); auto.
apply ltT_not_eqT; auto; apply eqT_sym; auto.
apply uniq_minusp with (l := (p, q)); simpl in |- *; auto.
case H1; auto.
absurd (ltT ltM a b); auto.
Qed.

Theorem minusP_inv3b :
forall (a b : Term A n) (p q s : list (Term A n)),
eqT a b ->
~ zeroP (A:=A) A0 eqA (n:=n) (minusTerm (A:=A) minusA (n:=n) a b) ->
minusP (pX a p) (pX b q) s ->
s = pX (minusTerm (A:=A) minusA (n:=n) a b) (minuspf p q).