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The notion of a weakly Mal'tsev category, as it was introduced in 2008 by the third author, is a generalization of the classical notion of a Mal'tsev category. It is well-known that a variety of universal algebras is a Mal'tsev category if…

Category Theory · Mathematics 2024-03-15 Nadja Egner , Pierre-Alain Jacqmin , Nelson Martins-Ferreira

We show that the category of N-complexes has a Str\om model structure, meaning the weak equivalences are the chain homotopy equivalences. This generalizes the analogous result for the category of chain complexes (N = 2). The trivial objects…

K-Theory and Homology · Mathematics 2012-07-31 James Gillespie

A categorial grammar assigns one of several syntactic categories to each symbol of the alphabet, and the category of a string is then deduced from the categories assigned to its symbols using two simple reduction rules. This paper…

Logic · Mathematics 2025-05-21 Maxim Vishnikin , Alexander Okhotin

The logic of definitions is a family of logics for encoding and reasoning about judgments, which are atomic predicates specified by inference rules. A definition associates an atomic predicate with a logical formula, which may itself depend…

Logic in Computer Science · Computer Science 2026-02-04 Nathan Guermond

We introduce a single-set axiomatisation of cubical $\omega$-categories, including connections and inverses. We justify these axioms by establishing a series of equivalences between the category of single-set cubical $\omega$-categories,…

Logic in Computer Science · Computer Science 2024-07-08 Philippe Malbos , Tanguy Massacrier , Georg Struth

We prove that certain triangulated categories are (weakly) approximable in the sense of A. Neeman. We prove that a triangulated $C$ that is compactly generated by a single object $G$ is weakly approximable if $C(G,G[i])=0$ for $i>1$ (we say…

K-Theory and Homology · Mathematics 2019-07-23 Mikhail V. Bondarko , Sergei V. Vostokov

We introduce the concept of weak average-case analysis as an attempt to achieve theoretical complexity results that are closer to practical experience than those resulting from traditional approaches. This concept is accepted in other areas…

Numerical Analysis · Mathematics 2016-01-01 Dennis Amelunxen , Martin Lotz

We introduce and study weak o-minimality in the context of complete types in an arbitrary first-order theory. A type $p\in S(A)$ is weakly o-minimal if for some relatively $A$-definable linear order, $<$, on $p(\mathfrak{C})$ every…

Logic · Mathematics 2026-02-24 Slavko Moconja , Predrag Tanović

In this paper, we define weakly coherent rings, and examine the transfer of these rings to homomorphic image, trivial ring extension, localization, and direct product. These results provide examples of weakly coherent rings that are not…

Commutative Algebra · Mathematics 2010-03-17 Chahrazade Bakkari , Najib Mahdou

There are a dozen definitions of weak higher categories, all of which loosen the notion of composition of arrows. A new approach is presented here, where instead the notion of identity arrow is weakened -- these are tentatively called fair…

Category Theory · Mathematics 2010-03-09 Joachim Kock

A weakly equivariant Hopf algebra is a Hopf algebra A with an action of a finite group G up to inner automorphisms. We show that each weakly equivariant Hopf algebra can be replaced by a Morita equivalent algebra B with a strict action of G…

Rings and Algebras · Mathematics 2012-05-07 Jennifer Maier , Thomas Nikolaus , Christoph Schweigert

This article is a survey of algebra in the $\infty$-categorical context, as developed by Lurie in "Higher Algebra", and is a chapter in the "Handbook of Homotopy Theory". We begin by introducing symmetric monoidal stable…

Algebraic Topology · Mathematics 2019-07-08 David Gepner

We define a homotopy relation between arrows of a category with weak equivalences, and give a condition under which the quotient by the homotopy relation yields the homotopy category. In the case of the fibrant-cofibrant objects of a model…

Category Theory · Mathematics 2018-04-13 Martin Szyld

In dealing with asymptotic approximation of possibly divergent nets of probability distributions, we are led to study uniform structures on the set of distributions. This paper identifies a class of such uniform structures that may be…

Probability · Mathematics 2010-11-23 Jan Pachl

We introduce the notion of exact dg category, which provides a differential graded enhancement of Nakaoka--Palu's notion of extriangulated category. We give a definition in complete analogy with Quillen's but where the category of…

Representation Theory · Mathematics 2024-02-23 Xiaofa Chen

Internal categories feature notions of limit and completeness, as originally proposed in the context of the effective topos. This paper sets out the theory of internal completeness in a general context, spelling out the details of the…

Category Theory · Mathematics 2020-04-21 Enrico Ghiorzi

We derive a new sufficient condition for the existence of {\omega}-categorical universal structures in classes of relational structures with constraints, augmenting results by Cherlin, Shelah, Chi, and Hubi\v{c}ka and Ne\v{s}et\v{r}il.…

Logic · Mathematics 2012-03-29 Christian Pech , Maja Pech

We construct a Quillen model structure on the category of spectral categories, where the weak equivalences are the symmetric spectra analogue of the notion of equivalence of categories.

K-Theory and Homology · Mathematics 2009-02-23 Goncalo Tabuada

A new class of languages of infinite words is introduced, called the max-regular languages, extending the class of $\omega$-regular languages. The class has two equivalent descriptions: in terms of automata (a type of deterministic counter…

Formal Languages and Automata Theory · Computer Science 2009-03-09 Mikolaj Bojanczyk

We prove a general theorem which includes most notions of "exact completion". The theorem is that "k-ary exact categories" are a reflective sub-2-category of "k-ary sites", for any regular cardinal k. A k-ary exact category is an exact…

Category Theory · Mathematics 2012-09-06 Michael Shulman