# Set

## Set

Collection of distinct objects that have a common characteristic (defining property) called elements in this set.

A set is extensionally defined when it is defined by the explicit list of its elements, such as: U = {6, 7, 8, 9, 10, 11, 12} or $$\mathbb{N}$$ = {0, 1, 2, 3, 4, 5, 6, 7, …}.

A set is intensionally defined when it is defined by one of its characteristic properties, such as: H = {x ∈ $$\mathbb{N}$$ | x > 5 and x < 13}.