x=w y
Reflexive : (a, a) ∈ R ⇒ a=w . a
Symmetric: (a, b) ∈ R ⇒(b, a) ∈/ R
not symmetric
S={(nm, qp) / q m=p n}
nm=qp
(ba, ba) ∈ S ⇒ ba=ba( Reflexive )
(ba, dc) ∈ S ⇒ a d=b c ⇒(dc, ba) ∈ S ( Symetric )
(ba, dc) ∈ S,(dc, fe) ∈ S
⇒(ba, fe) ∈ S
S is an equivalence relation but R is not an equivalence relation