2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78856We prove that strongly homotopy algebras (such as $A_\infty$, $C_\infty$, sh Lie, $B_\infty$, $G_\infty$,...) are homotopically invariant in the category of chain complexes. An important consequence is a rigorous proof that `strongly homotopy structures transfer over chain homotopy equivalences.'LaTeX 2.09, 31 pages, article 12pt + bezier, substantially revisedAlgebraic Topologytext