SET THEORY: Set theory , branch of mathematics that deals with the properties of well-defined collections of distinct objects, which may or may not be of a mathematical nature, such as numbers or functions . The sets are represented with capital letters. The objects are called elements or members of the set. Elements or members of the set. Can be anything: numbers, people, letters of the alphabet, other sets, and so on. To indicate that an object x is a member of a set A one writes x ∊ A , while x ∉ A indicates that x is not a member of A. Some Example of Sets A set of all positive integers A set of all the planets in the solar system A set of all the states in India A set of all the lowercase letters of the alphabet Representation of a Set Sets can be represented in two ways − Roster or Tabular Form Set Builder Notation Roster or Tabular Form The set is represented by listing all the elements comprising it. The elements are enc