diff -r b04070fc937b -r 26cbfb7944f9 text/ncat.tex --- a/text/ncat.tex Tue Oct 04 22:45:08 2011 -0700 +++ b/text/ncat.tex Thu Oct 06 12:55:57 2011 -0700 @@ -1143,11 +1143,15 @@ invariance in dimension $n$, while in the fields definition we instead remember a subspace of local relations which contain differences of isotopic fields. (Recall that the compensation for this complication is that we can demand that the gluing map for fields is injective.) -Thus a \nn{lemma-ize} system of fields and local relations $(\cF,U)$ determines an $n$-category $\cC_ {\cF,U}$ simply by restricting our attention to +Thus +\begin{lem} +\label{lem:ncat-from-fields} +A system of fields and local relations $(\cF,U)$ determines an $n$-category $\cC_ {\cF,U}$ simply by restricting our attention to balls and, at level $n$, quotienting out by the local relations: \begin{align*} \cC_{\cF,U}(B^k) & = \begin{cases}\cF(B) & \text{when $k