Question

What is set theory and how do you use or solve it?

Answer 1

set theory, branch of mathematics that deals with the properties of well-defined collections of objects, which may or may not be of a mathematical nature, such as numbers or functions. The theory is less valuable in direct application to ordinary experience than as a basis for precise and adaptable terminology for the definition of complex and sophisticated

Answer 2

any set is a subset of itself, and Ø is a subset of any set. If both A ⊆ B and B ⊆ A, then A and B have exactly the same members. Part of the set concept is that in this case A = B; that is, A and B are the same set.

Answer 3

thats from http://www.britannica.com/EBchecked/topic/536159/set-theory

Answer 4

hope that helps