Let R be a ring and n a fixed positive integer, we investigate the properties of n-strongly Gorenstein projective, injective and flat modules. Using the homological theory , we prove that the tensor product of an n-strongly Gorenstein projective (flat) right R -module and projective (flat) left R-module is also n-strongly Gorenstein projective (flat). Let R be a coherent ring ,we prove that the...

Topological relations are sometimes insufficient for differentiating spatial configurations of two objects with critical difference in their connection styles. In this paper, we present the projective 9-intersection model, which refines topological relations into projective binary relations by considering projective properties of the objects’ shapes. This is indeed a reformulation of projective...