From: Stephen Dalton 
Date: November 29, 2009 12:09:36 PM EST
To: James Propp 
Subject: Comments on 92.305 Assignment #8

Not much to say on this one!  The only problem that seemed to reappear on many papers was a quirk about notation for inverse functions.  Many students wrote $y \in g^{-1}(F) \iff f(y) \in F$, which is confused because it replaces the function $g$ with some impostor function $f$!  Just try to be consistent with the notation for inverse functions.  When you're talking about the inverse, use the same letter to denote the forward function, and vice versa.