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Related papers: Constructive sheaf models of type theory

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In this work, we introduce a novel approach based on algebraic topology to enhance graph convolution and attention modules by incorporating local topological properties of the data. To do so, we consider the framework of sheaf neural…

Machine Learning · Computer Science 2023-11-20 Gabriele Cesa , Arash Behboodi

We present a generative model of images based on layering, in which image layers are individually generated, then composited from front to back. We are thus able to factor the appearance of an image into the appearance of individual objects…

Machine Learning · Computer Science 2016-02-17 Jonathan Huang , Kevin Murphy

Martin-L\"of's Intuitionistic Theory of Types is becoming popular for formal reasoning about computer programs. To handle recursion schemes other than primitive recursion, a theory of well-founded relations is presented. Using primitive…

Logic in Computer Science · Computer Science 2008-02-03 Lawrence C. Paulson

In this article we give an equivariant version for the construction of generic models on presheaves of structures. We deal with first order structures endowed with a suitable action of some fixed group, say $G$; we call them $G$-structures.…

Logic · Mathematics 2016-04-28 Gabriel Padilla , Andrés Villaveces

In this note we present a work in progress whose main purpose is to establish a categorified version of sheaf theory. We present a notion of derived categorical sheaves, which is a categorified version of the notion of complexes of sheaves…

Algebraic Geometry · Mathematics 2008-04-09 B. Toën , G. Vezzosi

For a non-isotrivial family of surfaces of general type over a complex projective curve, we give upper bounds for the degree of the direct images of powers of the relative dualizing sheaf. They imply that, fixing the curve and the possible…

Algebraic Geometry · Mathematics 2009-10-31 E. Bedulev , E. Viehweg

We develop normalisation by evaluation (NBE) for dependent types based on presheaf categories. Our construction is formulated in the metalanguage of type theory using quotient inductive types. We use a typed presentation hence there are no…

Logic in Computer Science · Computer Science 2023-06-22 Thorsten Altenkirch , Ambrus Kaposi

A Sheaf Neural Network (SNN) is a type of Graph Neural Network (GNN) that operates on a sheaf, an object that equips a graph with vector spaces over its nodes and edges and linear maps between these spaces. SNNs have been shown to have…

A generalization of topos theory is proposed giving an abstract realization of such categories as, say, the categories of manifolds and of Grothendieck schemes on the one hand, and permitting one, on the other hand, a view on…

Category Theory · Mathematics 2007-05-23 Vladimir Molotkov

Sheaves of structures are useful to give constructions in universal algebra and model theory. We can describe their logical behavior in terms of Heyting-valued structures. In this paper, we first provide a systematic treatment of sheaves of…

Logic · Mathematics 2021-12-15 Hisashi Aratake

One of the main prerequisites for understanding sheaves on elementary toposes is the proof that a (Lawvere-Tierney) topology on a topos induces a closure operator on it, and vice-versa. That standard theorem is usually presented in a…

Category Theory · Mathematics 2021-07-26 Eduardo Ochs

This paper is the first in a series of papers in which we define and study a category of "sheaves of $\mathcal Z$-modules on the set of alcoves" that carries important information on the category of representations of semisimple Lie…

Representation Theory · Mathematics 2017-01-16 Peter Fiebig , Martina Lanini

Many complicated network problems can be easily understood on small networks. Difficulties arise when small networks are combined into larger ones. Fortunately, the mathematical theory of sheaves was constructed to address just this kind of…

Algebraic Topology · Mathematics 2013-08-22 Michael Robinson

The homotopical approach to intensional type theory views proofs of equality as paths. We explore what is required of an object $I$ in a topos to give such a path-based model of type theory in which paths are just functions with domain $I$.…

Logic in Computer Science · Computer Science 2023-06-22 Ian Orton , Andrew M. Pitts

We construct an abelian category A(G) of sheaves over a category of closed subgroups of the r-torus G and show it is of finite injective dimension. It can be used as a model for rational $G$-spectra in the sense that there is a homology…

Algebraic Topology · Mathematics 2007-05-23 J. P. C. Greenlees

This is an introduction to Grothendieck's descent theory, with some stress on the general machinery of fibered categories and stacks.

Algebraic Geometry · Mathematics 2007-06-13 Angelo Vistoli

As observed recently by various people the topos $\mathbf{sSet}$ of simplicial sets appears as essential subtopos of a topos $\mathbf{cSet}$ of cubical sets, namely presheaves over the category $\mathbf{FL}$ of finite lattices and monotone…

Category Theory · Mathematics 2021-03-15 Thomas Streicher , Jonathan Weinberger

We extend a result of Cisinski on the construction of cofibrantly generated model structures from (Grothendieck) toposes to locally presentable categories and from monomorphism to more general cofibrations. As in the original case, under…

Category Theory · Mathematics 2009-06-24 Marc Olschok

The aim of this paper is to give a unifying description of various constructions (subanalytic, semialgebraic, o-minimal site) using the notion of T-topology. We then study the category of T-sheaves.

Algebraic Geometry · Mathematics 2016-09-02 Mario J. Edmundo , Luca Prelli

This paper studies the homotopy theory of the Grothendieck construction using model categories and semi-model categories, provides a unifying framework for the homotopy theory of operads and their algebras and modules, and uses this…

Algebraic Topology · Mathematics 2026-05-20 Michael Batanin , Florian De Leger , David White