ref: 2c3e688c3f779f0abfaad887f13ab2b70c9f814a
parent: d5ce41f05bc322fa2fb4d0eee66080b3b3004853
author: Peter Mikkelsen <peter@pmikkelsen.com>
date: Tue Jun 29 21:58:24 EDT 2021
Add backtracking to the evaluator. This means we have to keep track of choicepoints which is implemented the easy but wasteful way for now. I have also added a number which is used to differentiate variables from different application of the clauses.