[TUHS] Typesetting Mathematics by Kernighan and Cherry, retypeset

[David du Colombier]

> https://9p.io/plan9/about.html has details on plan9, but the latest 
> versions are available under the MIT license.

All former and current Plan 9 releases are available
under the MIT license, since March 2021.

http://p9f.org/dl/index.html

https://github.com/plan9foundation/plan9

-- 
David du Colombier