Universal Relation
## Definition / Concept
The universal relation on $A$ contains every ordered pair in $A\times A$.
## Formula
$$R=A\times A$$
If:
$$n(A)=n$$
then:
$$n(R)=n^2$$
## Conditions / Special Cases
The universal relation is reflexive, symmetric and transitive.
Therefore:
$$R\text{ is an equivalence relation}$$
## Usage
- Used as an extreme case while classifying relations.