text/basic_properties.tex
changeset 961 c57afb230bb1
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960:bc4086c639b6 961:c57afb230bb1
    72 We define the {\it support} of a blob diagram $b$, $\supp(b) \sub X$, 
    72 We define the {\it support} of a blob diagram $b$, $\supp(b) \sub X$, 
    73 to be the union of the blobs of $b$.
    73 to be the union of the blobs of $b$.
    74 For $y \in \bc_*(X)$ with $y = \sum c_i b_i$ ($c_i$ a non-zero number, $b_i$ a blob diagram),
    74 For $y \in \bc_*(X)$ with $y = \sum c_i b_i$ ($c_i$ a non-zero number, $b_i$ a blob diagram),
    75 we define $\supp(y) \deq \bigcup_i \supp(b_i)$.
    75 we define $\supp(y) \deq \bigcup_i \supp(b_i)$.
    76 
    76 
       
    77 %%%%% the following is true in spirit, but technically incorrect if blobs are not embedded; 
       
    78 %%%%% we only use this once, so move lemma and proof to Hochschild section
       
    79 \noop{ %%%%%%%%%% begin \noop
    77 For future use we prove the following lemma.
    80 For future use we prove the following lemma.
    78 
    81 
    79 \begin{lemma} \label{support-shrink}
    82 \begin{lemma} \label{support-shrink}
    80 Let $L_* \sub \bc_*(X)$ be a subcomplex generated by some
    83 Let $L_* \sub \bc_*(X)$ be a subcomplex generated by some
    81 subset of the blob diagrams on $X$, and let $f: L_* \to L_*$
    84 subset of the blob diagrams on $X$, and let $f: L_* \to L_*$
    92 Assign to $b$ the acyclic (in positive degrees) subcomplex $T(b) \deq r\bullet\bc_*(S)$.
    95 Assign to $b$ the acyclic (in positive degrees) subcomplex $T(b) \deq r\bullet\bc_*(S)$.
    93 Note that if a diagram $b'$ is part of $\bd b$ then $T(b') \sub T(b)$.
    96 Note that if a diagram $b'$ is part of $\bd b$ then $T(b') \sub T(b)$.
    94 Both $f$ and the identity are compatible with $T$ (in the sense of acyclic models, \S\ref{sec:moam}), 
    97 Both $f$ and the identity are compatible with $T$ (in the sense of acyclic models, \S\ref{sec:moam}), 
    95 so $f$ and the identity map are homotopic.
    98 so $f$ and the identity map are homotopic.
    96 \end{proof}
    99 \end{proof}
       
   100 } %%%%%%%%%%%%% end \noop
    97 
   101 
    98 For the next proposition we will temporarily restore $n$-manifold boundary
   102 For the next proposition we will temporarily restore $n$-manifold boundary
    99 conditions to the notation. Let $X$ be an $n$-manifold, with $\bd X = Y \cup Y \cup Z$.
   103 conditions to the notation. Let $X$ be an $n$-manifold, with $\bd X = Y \cup Y \cup Z$.
   100 Gluing the two copies of $Y$ together yields an $n$-manifold $X\sgl$
   104 Gluing the two copies of $Y$ together yields an $n$-manifold $X\sgl$
   101 with boundary $Z\sgl$.
   105 with boundary $Z\sgl$.