 The first two principles are closure principles on the set. The third principle says that any two intrinsic properties that can be instantiated can be instantiated together any number of times. And the fourth says that if objects having two intrinsic properties can be in two regions, and those two regions can be in a particular spatial relation, then the regions can be in that relation while filled by objects having those properties. The third principle suffices to show that being such that a cube exists could not be in \(SI\), and the fourth to show that being a rock could not be.