You take copies of objects from A and B, but you relabel in all consistent ways. star product is where you take ordered pairs of copies. sequence is similar to what we did for unlabeled. it's A + A star A + A star, star A, and so forth. but you could have sets of objects like we did for urns and you can have objects arrange in a cyclic sequence for example. so those are the constructions that we can use richer set of constructions and leads to much richer set of objects to talk about. and again, what's important is that we have a transfer theorem. 