Designation of sets and their elements. Equality of sets. Subset ( inclusion ). Sum ( union ) of sets. Product ( intersection ) of sets. Difference ( complement ) of sets. Symmetric difference of sets. Properties of operations with sets. Sets are designated by capital letters, and their elements – by small letters. The record a R means, that an element а belongs to a set R, i.e. а is an element of the […]

## Basic notions. Examples of sets

Set. Element of a set. Finite set. Empty set. Infinite set. Countable set. Uncountable set. Convex set. Methods of description of sets. A set and an element of a set concern with category of primary notions, for which it’s impossible to formulate the strict definitions. So, we imply as sets usually collections of objects ( […]