On a Class of 2-Periodic Cohomology Theories.
On a sequence of K. A. Hardie
On cohomology of graded group categories
On exactness of long sequences of homology semimodules.
On subdirect irreducibility and its variants
On the categorical foundations of homological and homotopical algebra
On the homology theory of categories. I.
On the homology theory of categories. II.
On weak -homotopy equivalences of modules
Si definisce il gruppo di —omotopia di un singolo modulo e si introduce la nozione di equivalenza -omotopica debole. Sotto determinate condizioni per l'anello di base oppure per i moduli considerati, le equivalenze -omotopiche deboli coincidono con le equivalenze -omotopiche (forti).
On weak monomorphisms and weak epimorphisms in the category of pro-groups.
In this paper we characterize weak monomorphisms and weak epimorphisms in the category of pro-groups. Also we define the notion of weakly exact sequence and we study this notion in the category of pro-groups.