 But Paull and Sider went on to provide a new argument for that claim. They appealed to a set B containing just two properties, P and Q, and a set A containing only one property, M. An object has M just in case it has P, and some other object is Q. That is to say, Mx =df Px &amp; ∃yQy. This definition guarantees that A globally supervenes on B. They then described the following two worlds: