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Related papers: A topos for extended Weihrauch degrees

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In this paper we study Weihrauch reducibility for multi-valued functions on represented spaces. We call the corresponding equivalence classes Weihrauch degrees and we show that the corresponding partial order induces a lower semi-lattice…

Logic · Mathematics 2011-01-07 Vasco Brattka , Guido Gherardi

We identify a notion of reducibility between predicates, called instance reducibility, which commonly appears in reverse constructive mathematics. The notion can be generally used to compare and classify various principles studied in…

Logic · Mathematics 2023-06-22 Andrej Bauer

The Weihrauch degrees are a tool to gauge the computational difficulty of mathematical problems. Often, what makes these problems hard is their discontinuity. We look at discontinuity in its purest form, that is, at otherwise constant…

Logic · Mathematics 2024-07-19 Rupert Hölzl , Keng Meng Ng

Multi-valued functions are common in computable analysis (built upon the Type 2 Theory of Effectivity), and have made an appearance in complexity theory under the moniker search problems leading to complexity classes such as PPAD and PLS…

Computational Complexity · Computer Science 2015-12-31 Arno Pauly

In this paper we study a new approach to classify mathematical theorems according to their computational content. Basically, we are asking the question which theorems can be continuously or computably transferred into each other? For this…

Logic · Mathematics 2011-01-07 Vasco Brattka , Guido Gherardi

In this article, we give a full description of a topological many-one degree structure of real-valued functions, recently introduced by Day-Downey-Westrick. We also point out that their characterization of the Bourgain rank of a Baire-one…

Logic · Mathematics 2019-06-26 Takayuki Kihara

This paper presents categorical formulations of Turing, Medvedev, Muchnik, and Weihrauch reducibilities in Computability Theory, utilizing Lawvere doctrines. While the first notions lend themselves to a smooth categorical presentation,…

Logic · Mathematics 2025-02-19 Davide Trotta , Manlio Valenti , Valeria de Paiva

We investigate the uniform computational content of the open and clopen Ramsey theorems in the Weihrauch lattice. While they are known to be equivalent to $\mathrm{ATR_0}$ from the point of view of reverse mathematics, there is not a…

Logic · Mathematics 2023-06-22 Alberto Marcone , Manlio Valenti

Weihrauch complexity is now an established and active part of mathematical logic. It can be seen as a computability-theoretic approach to classifying the uniform computational content of mathematical problems. This theory has become an…

Logic · Mathematics 2023-02-09 Vasco Brattka

We introduce two new operations (compositional products and implication) on Weihrauch degrees, and investigate the overall algebraic structure. The validity of the various distributivity laws is studied and forms the basis for a comparison…

Logic in Computer Science · Computer Science 2023-06-22 Vasco Brattka , Arno Pauly

This paper introduces effectful toposes as an extension of the effective topos and investigates their structure relative to Lawvere-Tierney topologies. First, we formulate effectful toposes by lifting the evidenced frame, which is a…

Logic in Computer Science · Computer Science 2026-02-27 Rinta Yamada

In computable analysis typically topological spaces with countable bases are considered. The Theorem of Kreitz-Weihrauch implies that the subbase representation of a second-countable $T_0$ space is admissible with respect to the topology…

Logic · Mathematics 2026-04-03 Vasco Brattka , Emmanuel Rauzy

There is a way of assigning a realizability notion to each degree of incomputability. In our setting, we make use of Weihrauch degrees (degrees of incomputability/discontinuity of partial multi-valued functions) to obtain Lifschitz-like…

Logic · Mathematics 2025-05-07 Takayuki Kihara

We define a class of computable functions over real numbers using functional schemes similar to the class of primitive and partial recursive functions defined by G\"odel and Kleene. We show that this class of functions can also be…

Logic in Computer Science · Computer Science 2020-10-05 Keng Meng Ng , Nazanin R. Tavana , Yue Yang

We study the equational theory of the Weihrauch lattice with multiplication, meaning the collection of equations between terms built from variables, the lattice operations $\sqcup$, $\sqcap$, the product $\times$, and the finite…

Logic in Computer Science · Computer Science 2024-09-05 Eike Neumann , Arno Pauly , Cécilia Pradic

By the sometimes so-called MAIN THEOREM of Recursive Analysis, every computable real function is necessarily continuous. Weihrauch and Zheng (TCS'2000), Brattka (MLQ'2005), and Ziegler (ToCS'2006) have considered different relaxed notions…

Logic in Computer Science · Computer Science 2011-08-04 Martin Ziegler

In the topos approach to quantum theory, the spectral presheaf plays the role of the state space of a quantum system. We show how a notion of entropy can be defined within the topos formalism using the equivalence between states and…

Category Theory · Mathematics 2020-06-08 Carmen-Maria Constantin , Andreas Doering

In this article, we introduce a notion of reducibility for partial functions on the natural numbers, which we call subTuring reducibility. One important aspect is that the subTuring degrees correspond to the structure of the realizability…

Logic · Mathematics 2024-11-22 Takayuki Kihara , Keng Meng Ng

This paper classifies different fragments of the Galvin-Prikry theorem, an infinite dimensional generalization of Ramsey's theorem, in terms of their uniform computational content (Weihrauch degree). It can be seen as a continuation of…

Logic · Mathematics 2024-10-10 Alberto Marcone , Gian Marco Osso

This paper compares different representations (in the sense of computable analysis) of a number of function spaces that are of interest in analysis. In particular subspace representations inherited from a larger function space are compared…

Logic in Computer Science · Computer Science 2016-12-09 Arno Pauly , Florian Steinberg
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