We introduce the subcategory VRelR(H) of VRel(H) consisting of H-fuzzy reflexive relational space on sets and we study structures of VRelR(H) in a viewpoint of the topological universe introduced by L.D.Nel. We show that VRelPO(H) of VRelR(H). We show that VRelPR(H) [resp. VRelP (H) and VRelE(H)] is a topological universe over Set. Mathematics Subject Classification: 04A72, 18B10, 18D15

In this series of lectures we give an exposition of the seminal work of Devinatz, Hopkins, and Smith which is surrounding the classification of the thick subcategories of finite spectra in stable homotopy theory. The lectures are expository and are aimed primarily at non-homotopy theorists. We begin with an introduction to the stable homotopy category of spectra, and then talk about the celebra...

There are many different types of lenses, but largely they fall into the three classes of the title: set-based, delta-based and edit-based lenses. This paper develops some of the general relationships between those classes. The main results are that a category of set-based lenses is a full subcategory of a category of delta-based lenses determined by sending sets to codiscrete categories; that ...

Graded monoidal categories were introduced by Frohlich and C.T.C. ̈ Wall in 8 , where they presented a suitable abstract setting to study the Brauer group in equivariant situations. This paper is concerned with the analysis and classification of these graded monoidal categories, following a parallel treatment to that made in 2 for the non-monoidal case. In any graded monoidal category, its 1-com...

This article argues that the concept of anger is not well characterized from the classical perspective. Instead, its membership is graded, its borders are fuzzy, and its subcategories fail to form a true class-inclusion hierarchy. Ss rated potential anger subcategories (fury, jealousy, annoyance, etc.) and remembered instances of their own anger as varying in degree of membership in anger. Degr...

For an (n− 1)-Auslander algebra Λ with global dimension n, we give some necessary conditions for Λ admitting a maximal (n − 1)-orthogonal subcategory in terms of the properties of simple Λ-modules with projective dimension n − 1 or n. For an almost hereditary algebra Λ with global dimension 2, we prove that Λ admits a maximal 1orthogonal subcategory if and only if for any non-projective indecom...

Continuous lattices were characterised by Mart́ın Escardó as precisely the objects that are Kan-injective w.r.t. a certain class of morphisms. We study Kan-injectivity in general categories enriched in posets. An example: ω-CPO’s are precisely the posets that are Kan-injective w.r.t. the embeddings ω →֒ ω + 1 and 0 →֒ 1. For every class H of morphisms we study the subcategory of all objects Kan-in...

Here X is a topological space equal to the union of the closed subset Z and the open complement U , and D(Z), D(X), and D(U) are suitable derived categories of sheaves. The triangulated functors in a recollement must satisfy various conditions, most importantly that (i, i∗), (i∗, i ), (j!, j ), and (j, j∗) are adjoint pairs. The purpose of this note is to point out that, somewhat surprisingly, ...

An additive category is definable if it is equivalent to a definable subcategory of a module category Mod-R, meaning a full subcategory which is closed under direct products, direct limits (= directed colimits) and pure subobjects. Such a category D has associated to it a canonical model theory for its objects in the sense that each object D ∈ D becomes a structure for the associated language; ...