Relations in a Set:
Let consider R be a relation from A to B. If B = A, then R is known as a relation in A. Thus relation in a set A is a subset of A ΧA.
Identity Relation:
R is an identity relation if (a, b) € R iff a = b, a € A, b € A. In other terms, every element of A is belongs to only itself.
Universal Relation in a Set:
Assume A be any set and R be the set A Χ A, then R is known as the Universal Relation in A.
Void Relation in a Set:
Φ is known as Void Relation in a set.