diff -r fab3d057beeb -r 7afa2ffbbac8 text/evmap.tex --- a/text/evmap.tex Sat Oct 08 17:35:05 2011 -0700 +++ b/text/evmap.tex Wed Oct 12 15:10:54 2011 -0700 @@ -391,14 +391,21 @@ $h_2(b) \in \btc_3(X)$, also supported on $V$, such that $\bd(h_2(b)) = s(b) - b - h_1(\bd b)$ The general case, $h_k$, is similar. + +Note that it is possible to make the various choices above so that the homotopies we construct +are fixed on $\bc_* \sub \btc_*$. +It follows that we may assume that +the homotopy inverse to the inclusion constructed above is the identity on $\bc_*$. +Note that the complex of all homotopy inverses with this property is contractible, +so the homotopy inverse is well-defined up to a contractible set of choices. \end{proof} -The proof of Lemma \ref{lem:bc-btc} constructs a homotopy inverse to the inclusion -$\bc_*(X)\sub \btc_*(X)$. -One might ask for more: a contractible set of possible homotopy inverses, or at least an -$m$-connected set for arbitrarily large $m$. -The latter can be achieved with finer control over the various -choices of disjoint unions of balls in the above proofs, but we will not pursue this here. +%The proof of Lemma \ref{lem:bc-btc} constructs a homotopy inverse to the inclusion +%$\bc_*(X)\sub \btc_*(X)$. +%One might ask for more: a contractible set of possible homotopy inverses, or at least an +%$m$-connected set for arbitrarily large $m$. +%The latter can be achieved with finer control over the various +%choices of disjoint unions of balls in the above proofs, but we will not pursue this here. @@ -419,7 +426,7 @@ \eq{ e_{XY} : \CH{X \to Y} \otimes \bc_*(X) \to \bc_*(Y) , } -well-defined up to homotopy, +well-defined up to (coherent) homotopy, such that \begin{enumerate} \item on $C_0(\Homeo(X \to Y)) \otimes \bc_*(X)$ it agrees with the obvious action of @@ -459,7 +466,7 @@ \begin{thm} \label{thm:CH-associativity} The $\CH{X \to Y}$ actions defined above are associative. -That is, the following diagram commutes up to homotopy: +That is, the following diagram commutes up to coherent homotopy: \[ \xymatrix@C=5pt{ & \CH{Y\to Z} \ot \bc_*(Y) \ar[drr]^{e_{YZ}} & &\\ \CH{X \to Y} \ot \CH{Y \to Z} \ot \bc_*(X) \ar[ur]^{e_{XY}\ot\id} \ar[dr]_{\mu\ot\id} & & & \bc_*(Z) \\