UFO.UFO-A
Class AntiRigidSortal

UFO.UFO-A.AntiRigidSortal
Direct Known Subclasses:
Phase, Role

public class AntiRigidSortal

A universal U is anti-rigid if for every instance x of U, x is possibly (in the modal sense) not an instance of U. In other words, if x instantiates U in a given world w, then there must be a possible world w’ in which x does not instantiate U.