http://dspace.nbuv.gov.ua:80/handle/123456789/188576 Tue, 21 Apr 2026 07:51:01 GMT 2026-04-21T07:51:01Z http://dspace.nbuv.gov.ua:80/bitstream/id/564388/ http://dspace.nbuv.gov.ua:80/handle/123456789/188576 http://dspace.nbuv.gov.ua:80/handle/123456789/188723 Free abelian trioids Zhuchok, Yu.V. We construct a free abelian trioid and describe the least abelian congruence on a free trioid. Fri, 01 Jan 2021 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/188723 2021-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/188722 Cancellation ideals of a ring extension Tchamna, S. We study properties of cancellation ideals of ring extensions. Let R ⊆ S be a ring extension. A nonzero S-regular ideal I of R is called a (quasi)-cancellation ideal of the ring extension R ⊆ S if whenever IB = IC for two S-regular (finitely generated) R-submodules B and C of S, then B = C. We show that a finitely generated ideal I is a cancellation ideal of the ring extension R ⊆ S if and only if I is S-invertible. Fri, 01 Jan 2021 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/188722 2021-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/188721 Diagonal torsion matrices associated with modular data Singh, G. Modular data are commonly studied in mathematics and physics. A modular datum defines a finite-dimensional representation of the modular group SL₂(Z). Cuntz (2007) defined isomorphic integral modular data. Here we discuss isomorphic integral and non-integral modular data as well as non-isomorphic but closely related modular data. In this paper, we give some insights into diagonal torsion matrices associated to modular data. Fri, 01 Jan 2021 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/188721 2021-01-01T00:00:00Z http://dspace.nbuv.gov.ua:80/handle/123456789/188720 The structure of g-digroup actions and representation theory Rodríguez-Nieto, J.G.; Salazar-Díaz, O.P.; Velásquez, R. The aim of this paper is to propose two possible ways of defining a g-digroup action and a first approximation to representation theory of g-digroups. Fri, 01 Jan 2021 00:00:00 GMT http://dspace.nbuv.gov.ua:80/handle/123456789/188720 2021-01-01T00:00:00Z