Guillén Santos, FranciscoNavarro, Vicenç (Navarro Aznar)Pascual Gainza, PereRoig, Agustí2013-04-122013-04-122009-01-010166-8641https://hdl.handle.net/2445/34541Let $S_*$ and $S_*^\{infty}$ be the functors of continuous and differentiable singular chains on the category of differentiable manifolds. We prove that the natural transformation $i: S_*^\infty \rightarrow S_*$, which induces homology equivalences over each manifold, is not a natural homotopy equivalence.3 p.application/pdfeng(c) Elsevier B.V., 2009Topologia diferencialTopologia algebraicaÀlgebra homològicaDifferential topologyAlgebraic topologyHomological algebrainfo:eu-repo/semantics/article5768572013-04-12info:eu-repo/semantics/openAccess