Isabelle-HoTT - trying to make Isabelle/HoTT work with Isabelle 2021-1

	Commit message (Expand)	Author	Files	Lines
2020-05-27	1. Define Maybe in terms of other types. 2. Move More_Types to Spartan	Josh Chen	1	-28/+42
2020-05-26	Maybe and more List	Josh Chen	1	-0/+56