2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/64534We prove that the category of Hopf bimodules over any Hopf algebra has enough injectives, which enables us to extend some results on the unification of Hopf bimodule cohomologies of [T1,T2] to the infinite dimensional case. We also prove that the cup-product defined on these cohomologies is graded-commutative.17 pages; some proofs changed, references deletedK-Theory and Homology16E40, 16W30, 57T05text