diff -r edcf5835b3dd -r 553808396b6f text/basic_properties.tex --- a/text/basic_properties.tex Sun Feb 06 18:31:17 2011 -0800 +++ b/text/basic_properties.tex Sun Feb 06 20:54:10 2011 -0800 @@ -31,16 +31,16 @@ conditions to the notation. Suppose that for all $c \in \cC(\bd B^n)$ -we have a splitting $s: H_0(\bc_*(B^n, c)) \to \bc_0(B^n; c)$ +we have a splitting $s: H_0(\bc_*(B^n; c)) \to \bc_0(B^n; c)$ of the quotient map -$p: \bc_0(B^n; c) \to H_0(\bc_*(B^n, c))$. +$p: \bc_0(B^n; c) \to H_0(\bc_*(B^n; c))$. For example, this is always the case if the coefficient ring is a field. Then \begin{prop} \label{bcontract} -For all $c \in \cC(\bd B^n)$ the natural map $p: \bc_*(B^n, c) \to H_0(\bc_*(B^n, c))$ +For all $c \in \cC(\bd B^n)$ the natural map $p: \bc_*(B^n; c) \to H_0(\bc_*(B^n; c))$ is a chain homotopy equivalence -with inverse $s: H_0(\bc_*(B^n, c)) \to \bc_*(B^n; c)$. -Here we think of $H_0(\bc_*(B^n, c))$ as a 1-step complex concentrated in degree 0. +with inverse $s: H_0(\bc_*(B^n; c)) \to \bc_*(B^n; c)$. +Here we think of $H_0(\bc_*(B^n; c))$ as a 1-step complex concentrated in degree 0. \end{prop} \begin{proof} By assumption $p\circ s = \id$, so all that remains is to find a degree 1 map @@ -67,8 +67,13 @@ This follows from Properties \ref{property:disjoint-union} and \ref{property:contractibility}. \end{proof} -Recall the definition of the support of a blob diagram as the union of all the -blobs of the diagram. +%Recall the definition of the support of a blob diagram as the union of all the +%blobs of the diagram. +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 $\supp(y) \deq \bigcup_i \supp(b_i)$. + For future use we prove the following lemma. \begin{lemma} \label{support-shrink}