Epireflection operators vs perfect morphisms and closed classes of epimorphisms
Epireflection operators vs perfect morphisms and closed classes of epimorphisms
Operators are defined that yield basic Galois closure operations for almost every category. These give rise to a new and more general approach for characterization of epireflective subcategories, and construction of epireflective hulls. As a by-product, satisfactory characterizations of classes of perfect morphisms and ω-extendable epimorphisms are obtained. Detailed proofs …