It looks like a bad edit to the wiki. https://en.wikipedia.org/w/index.php?title=Pairwise_summation&diff=643560917&oldid=643548127 https://en.wikipedia.org/w/i

It looks like a bad edit to the wiki. https://en.wikipedia.org/w/index.php?title=Pairwise_summation&diff=643560917&oldid=643548127 https://en.wikipedia.org/w/index.php?title=Pairwise_summatio... ^ this user changed the error bounds, incorrectly. The worst case for the naive sum is pretty obviously epsilon*N (and is described that way on the Kahan sum page)