diff -r 982eca6e2663 -r 6c760675d461 text/blobdef.tex --- a/text/blobdef.tex Mon Jul 19 15:56:09 2010 -0600 +++ b/text/blobdef.tex Tue Jul 20 17:05:53 2010 -0700 @@ -134,12 +134,18 @@ Equivalently, we can define a ball decomposition inductively. A ball decomposition of $X$ is a topological space $X'$ along with a pair of disjoint homeomorphic $n-1$-manifolds $Y \subset \bdy X$, so $X = X' \bigcup_Y \selfarrow$, and $X'$ is either a disjoint union of balls, or a topological space equipped with a ball decomposition. \end{defn} +Even though our definition of a system of fields only associates vector spaces to $n$-manifolds, we can easily extend this to any topological space admitting a ball decomposition. +\begin{defn} +Given an $n$-dimensional system of fields $\cF$, its extension to a topological space $X$ admitting an $n$-ball decomposition is \todo{} +\end{defn} +\todo{This is well defined} Before describing the general case we should say more precisely what we mean by disjoint and nested blobs. -Disjoint will mean disjoint interiors. -Nested blobs are allowed to coincide, or to have overlapping boundaries. -Blob are allowed to intersect $\bd X$. +Two blobs are disjoint if they have disjoint interiors. +Nested blobs are allowed to have overlapping boundaries, or indeed to coincide. +Blob are allowed to meet $\bd X$. + However, we require of any collection of blobs $B_1,\ldots,B_k \subseteq X$ that $X$ is decomposable along the union of the boundaries of the blobs. \nn{need to say more here. we want to be able to glue blob diagrams, but avoid pathological