This is not a ratio and if you treat it as such you are wrong

No.13936042 ViewReplyOriginalReport
This is an operator (d/dx) acting on a function (y). (dy) is not a distance because it is not a number, you can not calculate an "infinitesimal" and if you think of it as "rise over run" you are wrong again, it is the tensor D??f? = ?'(t - x) f(x)