An expression like a*x+b can be written that way directly. It's only when you need to take advantage of some folds do you really start using newtypes. And in Ha

An expression like a*x+b can be written that way directly. It's only when you need to take advantage of some folds do you really start using newtypes. And in Haskell you'd usually just do a coerce on an entire collection of them.