[AlanSE]

Yes, this is the question I come to. The article betrays its own claim...

> Gustafson said that for training, 32-bit floating point is overkill and in some cases doesn’t even perform as well as the smaller 16-bit posits

If posits have a bit number, then they are not of variable accuracy. This is simply sloppy explaining.

At some point, rounding has to happen (call it an interval if you want, but you're not being helpful). As a programmer, I WANT rounding to happen. I depend on it. You don't break out the floats unless you are prepared for some information to be lost. If you try to never lose any information, then you wind up with a monstrosity like Maple and Mathematica in which all steps need to be curated by hand to occasionally reduce the giant glob of fractions and implicit solves into something concrete, but imperfect.

I read the article and took a glance at https://www.johndcook.com/blog/2018/04/11/anatomy-of-a-posit..., but I'm still completely unable to answer this question of how accuracy is shed.