>It's because the composition of linear (actually also affine) functions is still just linear (affine). Except you can "compose" affine functions using Horner'

>It's because the composition of linear (actually also affine) functions is still just linear (affine). Except you can "compose" affine functions using Horner's schema to get any polynomial... No need to sprinkle tiny non linearities. It's a buffet. Grab as much as you need.