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This is theorem 13.6 in Munkres' Elements of Algebraic Topology. I'm trying to go through this, but I can't prove it. Can someone do this one please?
Btw, its "Choose a partial ordering of the vertices of K that induces a linear ordering on the vertices of each simplex of K. Define \phi:C_p(K)\to C_p'(K) by letting \[\phi([v_0,...,v_p])=(v_0,...,v_p)\] if v_0<v_1<...<v_p in the given ordering. Define \psi:C_p'(K)\to C_p(K) by
\[\psi((w_0,...,w_p))=\begin{cases}[w_0,...,w_p] & \text{if the }w_i \text{ are distinct} \\ 0 * \text{otherwise} \end{cases} \]
Then \phi,\psi are augmentation-preserving chain maps that are chian homotopy inverses.
Thanks! The sooner the better of course, much appreciated. (Apply the acyclic carrier theorem)
<br /> \phi<br /> [\latex]
Btw, its "Choose a partial ordering of the vertices of K that induces a linear ordering on the vertices of each simplex of K. Define \phi:C_p(K)\to C_p'(K) by letting \[\phi([v_0,...,v_p])=(v_0,...,v_p)\] if v_0<v_1<...<v_p in the given ordering. Define \psi:C_p'(K)\to C_p(K) by
\[\psi((w_0,...,w_p))=\begin{cases}[w_0,...,w_p] & \text{if the }w_i \text{ are distinct} \\ 0 * \text{otherwise} \end{cases} \]
Then \phi,\psi are augmentation-preserving chain maps that are chian homotopy inverses.
Thanks! The sooner the better of course, much appreciated. (Apply the acyclic carrier theorem)
<br /> \phi<br /> [\latex]
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