HoTT/book — pull request #317 by mikeshulman (2013-06-24 06:20:55+00:00)
Title: a remark about alternative universe handling

Also from Francois Dorais:
http://dorais.org/archives/1425#comment-634
This is just a first try, anyone should feel free to improve it. The vertical spacing is a bit ugly in the letter version as this new paragraph pushes the Exercises onto the next page.