text/blobdef.tex
changeset 257 ae5a542c958e
parent 222 217b6a870532
child 313 ef8fac44a8aa
--- a/text/blobdef.tex	Wed May 05 22:58:45 2010 -0700
+++ b/text/blobdef.tex	Fri May 07 11:18:39 2010 -0700
@@ -135,6 +135,9 @@
 (The case $B_i = B_j$ is allowed.
 If $B_i \sub B_j$ the boundaries of $B_i$ and $B_j$ are allowed to intersect.)
 If a blob has no other blobs strictly contained in it, we call it a twig blob.
+\nn{need to allow the case where $B\to X$ is not an embedding
+on $\bd B$.  this is because any blob diagram on $X_{cut}$ should give rise to one on $X_{gl}$
+and blobs are allowed to meet $\bd X$.}
 \item Fields (boundary conditions) $c_i \in \cC(\bd B_i)$.
 (These are implied by the data in the next bullets, so we usually
 suppress them from the notation.)
@@ -188,6 +191,11 @@
 The $(-1)^j$ factors imply that the terms of $\bd^2(b)$ all cancel.
 Thus we have a chain complex.
 
+We define the {\it support} of a blob diagram $b$, $\supp(b) \sub X$, 
+to be the union of the blobs of $b$.
+For $y \in \bc_*(X)$ with $y = \sum c_i b_i$ ($c_i$ a non-zero number, $b_i$ a blob diagram),
+we define $\supp(y) \deq \bigcup_i \supp(b_i)$.
+
 We note that blob diagrams in $X$ have a structure similar to that of a simplicial set,
 but with simplices replaced by a more general class of combinatorial shapes.
 Let $P$ be the minimal set of (isomorphisms classes of) polyhedra which is closed under products