Mereology (“mee-ree-ology”) unproblematically incorporates an analogue of these objects’ rule of unrestricted comprehension, which was originally called Basic Law V (“five”). Type theory was developed to resolve a paradox about these objects, which is often compared to a barber who can’t shave himself. Gottlob (10[1])Frege (10[1])(“FRAY-guh”) defined numbers as these objects, which is also done in Zermelo-Frankel (10[1])theory. The naïve theory of these objects is subject to Russell’s paradox, which concerns one of these objects containing all of these objects that do not contain (10[1])themselves. (10[1])De Morgan’s laws axiomatize the union (10[1])and intersection operations on these objects. For 10 points, name these unordered collections of objects. ■END■ (10[1])