xRy ⇒ x - y is zero or irrational xRx ⇒ 0 ∴ reflective if xRy ⇒ x - y is zero or irrational ⇒ y - x is zero or irrational ∴ yRx symmetric xRy ⇒ x - y is 0 or irrational yRz ⇒ y - z is 0 or irrational then (x - y) + (y - z) = x - z may be rational ∴ It is not transitive