Extensions of elementary duality
Elementary duality of pp-formulas for modules [see \textit{I. Herzog}, Trans. Am. Math. Soc. 340, 37-69 (1993), and \textit{M. Prest}, Model theory and modules (Lond. Math. Soc. Lect. Note Ser. 130) (1988; Zbl 0634.03025)] is extended to abelian structures and to some infinitary formulas and theories. The authors also give a relationship between elementary duality and a categorical duality. They finally give new proofs of known algebraic facts about absolutely pure and flat modules.
scientific article; zbMATH DE number 561570