As those who are familiar with Numerical Analysis know, every machine has its own 'epsilon', ie the smallest distance that can be recognized by the floating point arithmetic of the machine. It is usually at the order of 10^(-16), so if |x-y|
But if that length is the smallest one, then we certainly live in an absolutely discrete local universe, so every attempt to describe it with differential equations with respect to space coordinates is a heroic assumption!
Yes, but as we are reaching at the Planck length (Lp) then our differential operators are transformed to a play-game, something that sometime had meaning and now has not: imagine all modern Physics as tries to explain the origin of our local universe based on a tool that is not well defined.