2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67441This mostly expository paper records some basic facts about towers of homotopy fiber sequences. We give a proof that a pairing of towers induces a pairing of associated spectral sequences, for towers of spaces and towers of spectra.Algebraic Topology55T05Multiplicative structures on homotopy spectral sequences Itext