HoTT/book — pull request #390 by ecavallo (2013-07-06 02:57:18+00:00)
Title: typo in Lemma 8.6.10 (freudlemma)

Two points are variously referred to as a_1,a_2 and x,y. Went with a_1,a_2 since x's are being used for elements of X elsewhere.