<P> The absolute difference of two real numbers x, y is given by x − y, the absolute value of their difference . It describes the distance on the real line between the points corresponding to x and y . It is a special case of the L distance for all 1 ≤ p ≤ ∞ and is the standard metric used for both the set of rational numbers Q and their completion, the set of real numbers R . </P> <P> As with any metric, the metric properties hold: </P>

The difference of the absolute value of two numbers