I should add to that, of course, that any attempt to translate maths into ordinary English risks ambiguity or omission. I did not say, though it was my intention, that epsilon should be bigger than zero, as that is a well understood convention is science generally. Clearly, an epsilon of -1000 would make a lot of numbers equal that we did not intend. If you want to include that as an example of sloppiness, feel free. While we are at it, I also assumed scalar quantities, not, for example, complex numbers. All such things would have been explicit had I used formal notation not English, but it would have limited the readership even more than tedious pedantry (and is painful to enter as html)