Martins-Ferreira, Nelson2025-06-172025-06-172015-10Martins-Ferreira, N. New Wide Classes of Weakly Mal’tsev Categories. Appl Categor Struct 23, 741–751 (2015). https://doi.org/10.1007/s10485-014-9377-40927-28521572-9095http://hdl.handle.net/10400.8/13310The following classes of categories are shown to be weakly Mal’tsev in the sense of the author: (i) a suitable class of algebras with cancellation; (ii) the dual of any quasi-adhesive category; (iii) the dual of any extensive category with pullback-stable epimorphisms; (iv) the dual of any solid quasi-topos. The examples in (i) include all the Mal’tsev varieties of algebras such as groups, rings, Lie algebras, etc., but also distributive lattices and commutative monoids with cancellation. The examples in (ii)-(iv) capture many of the familiar aspects of topological spaces. © 2014, Springer Science+Business Media Dordrecht.engExtensive categoryLocal coproductPullback-stable epimorphismQuasi-adhesive categorySolid quasi-toposStable coproductTopological spaceVan Kampen squareWeakly Mal’tsev categoryjournal article10.1007/s10485-014-9377-4