Err.. I would argue that (+1)^2+(-1)^2 would not yield a false positive. You are right that the explanation is incomplete, though. The squaring provides an 'a

Err.. I would argue that (+1)^2+(-1)^2 would not yield a false positive. You are right that the explanation is incomplete, though. The squaring provides an 'absolute value' effect as well as disproportionately weighting larger alphabetical distances.