Strong embedding of category of all groupoids into category of semigroups
We describe a sequent calculus μLJ with primitives for inductive and coinductive datatypes and equip it with reduction rules allowing a sound translation of Gödel’s system T. We introduce the notion of a μ-closed category, relying on a uniform interpretation of open μLJ formulas as strong functors. We show that any μ-closed category is a sound model for μLJ. We then turn to the construction of a concrete μ-closed category based on Hyland-Ong game semantics. The model relies on three main ingredients:...
We show that, on a category of many-sorted sets, the only functors that admit a cartesian strength are those that are given componentwise.
Let be an Artin algebra. In view of the characterization of finitely generated Gorenstein injective -modules under the condition that is a cocompatible -bimodule, we establish a recollement of the stable category . We also determine all strongly complete injective resolutions and all strongly Gorenstein injective modules over .
Let be a self-orthogonal class of left -modules. We introduce a class of modules, which is called strongly -Gorenstein modules, and give some equivalent characterizations of them. Many important classes of modules are included in these modules. It is proved that the class of strongly -Gorenstein modules is closed under finite direct sums. We also give some sufficient conditions under which the property of strongly -Gorenstein module can be inherited by its submodules and quotient modules....
We interpret the collection of invertible bimodules as a groupoid and call it the Picard groupoid. We use this groupoid to generalize the classical construction of crossed products to what we call groupoid crossed products, and show that these coincide with the class of strongly groupoid graded rings. We then use groupoid crossed products to obtain a generalization from the group graded situation to the groupoid graded case of the bijection from a second cohomology group, defined by the grading...
À travers l'étude d'un modèle de représentation des connaissances comme catégorie de faisceaux de traits localement définis ; ce texte montre que la théorie des topoï permet de décrire formellement l'émergence d'une logique intrinsèque à partir d'une approche relationnelle, qu'elle soit structurale ou cognitive. On peut alors caractériser mathématiquement le défaut d'intensionnalité des modèles classiques, et montrer qu'une solution est dans la mathématisation de structures entièrement relationnelles....
This is a survey paper on applications of the representation theory of the symmetric group to the theory of polynomial identities for associative and nonassociative algebras. In §1, we present a detailed review (with complete proofs) of the classical structure theory of the group algebra of the symmetric group over a field of characteristic 0 (or ). The goal is to obtain a constructive version of the isomorphism where is a partition of and counts the standard tableaux of shape ....