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Aug 4, 2014 at 6:45 comment added Cusp I am little confused. Is $C$ a given fixed compact set or for any compact set $C$ and $f$ the lift exists?
Aug 3, 2014 at 1:01 vote accept rgnrmllbrg
Aug 3, 2014 at 0:46 comment added Eric Wofsey $C$ is not a simplex but the union of the images of the simplices in $X$. In your $S^1$ example, $C$ would be all of $S^1$, which does not lift to $\mathbb{R}$.
Aug 3, 2014 at 0:25 comment added Eric Wofsey For any $c\in H_n(X)$, there is some compact subset $C\subseteq X$ such that $c$ is in the image of $H_n(C)\to H_n(X)$ (namely, let $C$ be the union of the images of all the simplices appearing in a representative of $c$). The inclusion $C\to X$ lifts to $E$, and hence $c$ also lifts to $H_n(E)$.
Aug 3, 2014 at 0:13 history answered Eric Wofsey CC BY-SA 3.0