Luis Fernando Tzec Poot

A second note on homological systems

Let $\left( Δ; Ω, \leq \right)$ be a b-homological system and $\widetilde{\cal F} \left( Δ\right)$ the category of the extended $Δ-$filtered modules. Here there is a proof that $\widetilde{\cal F} \left( Δ\right)$ is closed under direct summands.