The category of Set-valued presheaves on a small category B is a topos. Replacing Set by a bicategory S whose objects are sets and morphisms are spans, relations, or partial maps, we consider a category Lax(B,S) of S-valued lax functors on B. When S = Span, the resulting category is equivalent to Cat/B, and hence, is rarely even cartesian closed. Restricting this equivalence gives rise to expon...

the aim of this paper is to study the categorical relations betweenmatroids, goetschel-voxman’s fuzzy matroids and shi’s fuzzifying matroids.it is shown that the category of fuzzifying matroids is isomorphic to that ofclosed fuzzy matroids and the latter is concretely coreflective in the categoryof fuzzy matroids. the category of matroids can be embedded in that offuzzifying matroids as a simul...

The theory of finitary biframes as order-theoretical duals bitopological spaces is explored. category a coreflective subcategory that biframes. Some the advantages adopting pointfree notion bispaces are studied. In particular, it shown for every biframe there which plays role analogue to assembly in frames: L A(L) with universal property analogous frame; and such its main component isomorphic o...

We prove that, in a triangulated category with combinatorial models, every localizing subcategory is coreflective and every colocalizing subcategory is reflective if a certain large-cardinal axiom (Vopěnka’s principle) is assumed true. It follows that, under the same assumptions, orthogonality sets up a bijective correspondence between localizing subcategories and colocalizing subcategories. Th...

We prove a structure result on proper extensions of two-sided restriction semigroups in terms partial actions, generalizing respective results for monoids and inverse upgrading the latter. introduce study several classes actions that generalize semigroups. establish an adjunction between category P(S) semigroup S A(S) subject to certain conditions going back work O'Carroll. In A(S), we specify ...

This paper develops a concept of 2-categorical algebraic quantum field theories (2AQFTs) that assign locally presentable linear categories to spacetimes. It is proven ordinary AQFTs embed as coreflective full 2-subcategory into the 2-category 2AQFTs. Examples 2AQFTs do not come from via this embedding are constructed by local gauging construction for finite groups, which admits physical interpr...

In this paper,  it is shown that the category of $L$-ordered fuzzifying convergence spaces contains the category of pretopological $L$-ordered fuzzifying convergence spaces as a bireflective subcategory and the latter contains the category of topological $L$-ordered fuzzifying convergence spaces as a bireflective subcategory. Also, it is proved that the category of $L$-ordered fuzzifying conver...

We lay down the foundations for a pointfree theory of Pervin spaces. A space is set equipped with bounded sublattice its powerset, and it known that these objects characterize those quasi-uniform spaces are transitive totally bounded. The notion space, which we call Frith frame, consists frame generating sublattice. In this paper introduce study category frames show classical dual adjunction be...