On Wednesday, June 27, 2012 4:15:14 AM UTC-4, djmpark wrote: > What is the justification for the following? > > > > 0. x + 1. y > > > > 0. + 1. y >
This appears to be an active area of Mathematica development. I think WRI improves their definition of "zero" with each release. Perhaps the next spin will give at least a more consistent result (0. + 1. y = 1. y), though not your desired one. If I recall correctly, earlier releases gave 0. * x -> 0. * x .