proposition: Theorem test_trans: forall n1 n2 n3, test n1 n2 = test n2 n3 -> test n1 n3 = test n1 n2.
proof: Proof. intros n1; elim n1; simpl; auto; clear n1. intros n2; elim n2; simpl; auto; clear n2. intros n2 Rec n3; elim n3; simpl; auto; clear n3. intros; discriminate. intros n1 Rec n2; elim n2; clear n2; simpl; auto. intros n3; elim n3; simpl; auto; clear n3. intros; discriminate. intros n2 Rec1 n3; elim n3; simpl; auto; clear n3. Qed.
imports: List Permutation UList