So this is exactly this. So we've written, so in this last step we just did, this thing over here is this thing right over here. And of course we have to add it, so I'll put a plus out front. We're almost done with this stage of the simplification. So over here we have a common 2mb. So let's put a plus 2mb times, once again, x1 plus x2 plus all the way to xn. So this term right over here is the exact same thing as this term over here.