intros a b; case a; case b; simpl in |- *; auto.
intros a0 m a1 m0 H'; elim H'; intros H'0 H'1; rewrite H'1; clear H'; auto.
split; auto.
apply (eqA_trans _ _ _ _ _ _ _ _ _ cs) with (y := multA A1 a0); auto.
apply (eqA_sym _ _ _ _ _ _ _ _ _ cs).
apply multA_A1_l with (1 := cs); auto.
apply multA_eqA_comp with (1 := cs); auto.
apply (eqA_sym _ _ _ _ _ _ _ _ _ cs); auto.
apply sym_eq; unfold M1 in |- *; apply mult_mon_zero_l.
Qed.

Theorem T1_multTerm_r :
forall a b : Term, eqTerm a T1 -> eqTerm b (multTerm b a).