For a given class of R-modules Q, module M is called Q-copure Baer injective if any map from left ideal R into can be extended to M. Depending on the this concept both dualization and generalization pure injectivity. We show that every embedded as submodule module. Certain types rings are characterized using properties modules. example ring Q-coregular only R-module injective.

It is shown that the Baer–Kaplansky Theorem can be extended to all abelian groups provided rings of endomorphisms are replaced by trusses corresponding heaps. That is, every group determined up isomorphism its endomorphism truss and between two associated some [Formula: see text] induced an element from text]. This correspondence then modules over a ring considering heaps modules. proved heap m...

Abstract Twisted étale groupoid algebras have recently been studied in the algebraic setting by several authors connection with an abstract theory of Cartan pairs rings. In this paper we show that extensions ample groupoids correspond a precise manner to Boolean inverse semigroups. particular, discrete twists over certain abelian semigroups, and they are classified Lausch’s second cohomology gr...

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