proposition: Remark add_reduce13 : forall x1 x2 y w z a b : Z, x1 = x2 -> w = y -> (b + a < 0)%Z -> (x1 + b + (y + (z + a)) < x2 + (w + z))%Z.
proof: Proof. intros; omega. Qed.
imports: List DistributedReferenceCounting.machine2.invariant8