yacctt: Yet Another Cartesian Cubical Type Theory

This is an extremely experimental implementation of a cartesian cubical type theory based on https://arxiv.org/abs/1712.01800 written by Anders Mörtberg and Carlo Angiuli. It is mainly meant as proof of concept and for experimentation with new cubical features and ideas.

It is based on the code base of https://github.com/mortberg/cubicaltt/.