A ** set** is collection of different mathematical objects called elements, which can be numbers, people, colours, matrices, etc. Examples of sets are {4, 20, 83, 1059, …} and {red, blue, cyan, grey}, where the former is an infinite set and the latter is a finite set. Two sets and are equal if they have the same elements, e.g. and . A set with no element, denoted by , is called an empty set. An element in a set is denoted by .

A ** subset** is an equal or smaller collection of elements of a particular set. With reference to the above diagram, the set is a subset of the set , which is mathematically denoted by . Similarly, and .

###### Question

Is a set.

###### Answer

No, because a set is defined as a collection of different elements.