FC-Pure Injectivity and FC-Pure Flatness and Its Relationship to Two Famous Problems of Kothe and Kaplansky
Let S be a class of left R-modules. An R-module M is said to be S-pure injective (resp. S-pure projective) if M has the injective (resp. projective) property respect to each S-pure exact sequence. Also, an R-module M is said to be S-pure flat if M has the flat property respect to each S-pure exact sequence. As Puninski (1994), let us fix a few of the most common purities S of R-modules.