## Secret history

February 5, 2012

One of the deepest results to emerge from Hall’s school was […] This was obtained by Hall’s student Peter Stroud, who was tragically killed in an accident shortly after completing his doctorate; as a result, the proof was never published, and remains quite difficult to get at (Stroud’s thesis may be consulted in the Cambridge University Library, but photocopying is not allowed).

Dan Segal, Words. Notes on verbal width in groups, Cambridge University Press, 2009.