--- a/pnas/pnas.tex Wed Nov 24 09:57:41 2010 -0700
+++ b/pnas/pnas.tex Mon Nov 29 10:01:34 2010 -0700
@@ -660,8 +660,8 @@
\item the $s_i$'s corresponding to the other pieces are single fields (linear combinations with only one term).
\end{itemize}
%that for any innermost blob $B$, the field on $B$ goes to zero under the gluing map from $\cC$.
-\nn{yech}
We call such linear combinations which evaluate to zero on a blob $B$ a ``null field on $B$".
+% could maybe say something here like "if blobs have nice complements then this is just...."
The differential acts on a $k$-blob diagram by summing over ways to forget one of the $k$ blobs, with alternating signs.