Whenever you havean equivalence relation R on a set A, it divides into subsets called equivalenceclasses. Hereisthedeï¬nition: Deï¬nition11.4 Suppose R isanequivalencerelationonaset A. Givenany element a2 A, the equivalence class containing is the subset 'x2 A: xRaâ of A consistingofalltheelementsof A thatrelateto a.80 Relations Example11.7 Here A Ë'b ,c d eâ ,and R isthefollowingrelationon A: R Ë'(b,b),(b,c),(c,b),(c,c),(d,d),(b,d),(d,b),(c,d),(d,c)â .Thisrelationis not reï¬exive,foralthough bRb, cRc and dRd ,itis not truethat eRe.