diff -r 591265710e18 -r 5702ddb104dc text/appendixes/moam.tex --- a/text/appendixes/moam.tex Thu Jul 29 19:48:59 2010 -0400 +++ b/text/appendixes/moam.tex Thu Jul 29 21:44:49 2010 -0400 @@ -35,6 +35,20 @@ This is a standard result; see, for example, \nn{need citations}. We will build a chain map $f\in \Compat(D^\bullet_*)$ inductively. -Choose $f(x_{0j})\in D^{0j}_0$ for all $j$. -\nn{...} -\end{proof} \ No newline at end of file +Choose $f(x_{0j})\in D^{0j}_0$ for all $j$ +(possible since $D^{0j}_0$ is non-empty). +Choose $f(x_{1j})\in D^{1j}_1$ such that $\bd f(x_{1j}) = f(\bd x_{1j})$ +(possible since $D^{0l}_* \sub D^{1j}_*$ for each $x_{0l}$ in $\bd x_{1j}$ +and $D^{1j}_*$ is 0-acyclic). +Continue in this way, choosing $f(x_{kj})\in D^{kj}_k$ such that $\bd f(x_{kj}) = f(\bd x_{kj})$ +We have now constructed $f\in \Compat(D^\bullet_*)$, proving the first claim of the theorem. + +Now suppose that $D^{kj}_*$ is $k$-acyclic for all $k$ and $j$. +Let $f$ and $f'$ be two chain maps (0-chains) in $\Compat(D^\bullet_*)$. +Using a technique similar to above we can construct a homotopy (1-chain) in $\Compat(D^\bullet_*)$ +between $f$ and $f'$. +Thus $\Compat(D^\bullet_*)$ is 0-connected. +Similarly, if $D^{kj}_*$ is $(k{+}i)$-acyclic then we can show that $\Compat(D^\bullet_*)$ is $i$-connected. +\end{proof} + +\nn{do we also need some version of ``backwards" acyclic models? probably}