Let A={1,2,3,4} and R be a relation in A given by R={(1,1),(2,2),(3,3),(4,4),(1,2),(2,1),(3,1),(1,3)}Then R is

R={(1,1)(2,2)(3,3)(4,4),(1,2),(2,1),(3,1),(1,3)}As (1,1)(2,2)(3,3)(4,4)∈R∴R is reflexive(1,2)and (2,1)∈R⇒(1,1)∈Rsimilarly,for other elements ,hence R is transitive ∴R is equivalence Relation