On Sat, Aug 8, 2009 at 10:39 AM, Prof. John C Nash<nashjc at uottawa.ca> wrote: > I would urge inclusion in the documentation of the +0, -0 example(s) if > there is NOT a way in R to distinguish these. There are occasions where it For single numbers try this: x <- +0 y <- -0 identical(x, y) && identical(1/x, 1/y) # FALSE