--- a/pnas/pnas.tex	Wed Feb 09 18:21:58 2011 -0800
+++ b/pnas/pnas.tex	Mon Feb 14 08:45:47 2011 +1100
@@ -1138,7 +1138,7 @@
 \end{equation*}
 We think of this map as being associated to a surgery which cuts $M$ out of $M\cup_E R$ and
 replaces it with $N$, yielding $N\cup_E R$.
-(This is a more general notion of surgery that usual: $M$ and $N$ can be any manifolds
+(This is a more general notion of surgery than usual: $M$ and $N$ can be any manifolds
 which share a common boundary.)
 In analogy to Hochschild cochains, we will call elements of $\hom_A(\bc_*(M), \bc_*(N))$ ``blob cochains".