 However, weak and intermediate global supervenience are not equivalent to strong individual supervenience even when extrinsic properties are let into the base—more precisely, when the base is closed under the relevant property-forming operations. So, perhaps they have distinctive philosophical work to do, work that cannot be done by strong individual supervenience. For example, Sider (1999) appeals to weak global supervenience to handle cases of spatio-temporal coincidence, though he retracts this in his (2008). See  Section 5.5.