ref: 1c8789198373a52da9e80dc9b2b1ee2b67af61c4
parent: 2a77288e28f2725b5621c239d2393d49f61993e8
author: Peter Mikkelsen <peter@pmikkelsen.com>
date: Thu Jul 15 20:42:49 EDT 2021
Make operators local to each module, and implement some more correct prettyprint code, used by write_term