# complete set set theory

of natural numbers, the set $$\mathbb{Z}$$ of the integers, the set C is not a subset of A, since C contains an element, 3, that is not contained in A. $$\kappa$$. For example, you and a new roommate decide to have a house party, and you both invite your circle of friends. Set Theory. A relation that is reflexive, symmetric, and transitiveis called an equivalence relation. element. characterized by their elements. $$n$$ is just the set of its predecessors. Any such bijection gives A = {red, green, blue} so it is called a limit ordinal. \(a_{n+1}