English
Related papers

Related papers: Directed type theory, with a twist

200 papers

In this paper, we present a directed homotopy type theory for reasoning synthetically about (higher) categories, directed homotopy theory, and its applications to concurrency. We specify a new `homomorphism' type former for Martin-L\"of…

Logic in Computer Science · Computer Science 2018-07-30 Paige Randall North

Directed Algebraic Topology is beginning to emerge from various applications. The basic structure we shall use for such a theory, a 'd-space', is a topological space equipped with a family of 'directed paths', closed under some operations.…

Algebraic Topology · Mathematics 2007-05-23 Marco Grandis

Homotopy type theory is a formal language for doing abstract homotopy theory -- the study of identifications. But in unmodified homotopy type theory, there is no way to say that these identifications come from identifying the path-connected…

Category Theory · Mathematics 2022-04-06 David Jaz Myers

We present a new model of Guarded Dependent Type Theory (GDTT), a type theory with guarded recursion and multiple clocks in which one can program with, and reason about coinductive types. Productivity of recursively defined coinductive…

Logic in Computer Science · Computer Science 2020-04-14 Aleš Bizjak , Rasmus Ejlers Møgelberg

We introduce Displayed Type Theory (dTT), a multi-modal homotopy type theory with discrete and simplicial modes. In the intended semantics, the discrete mode is interpreted by a model for an arbitrary $\infty$-topos, while the simplicial…

Category Theory · Mathematics 2026-01-14 Astra Kolomatskaia , Michael Shulman

This thesis captures the ongoing development of twisted cubes, which is a modification of cubes (in a topological sense) where its homotopy type theory does not require paths or higher paths to be invertible. My original motivation to…

Logic in Computer Science · Computer Science 2023-07-06 Gun Pinyo

Homotopy type theory is a new branch of mathematics, based on a recently discovered connection between homotopy theory and type theory, which brings new ideas into the very foundation of mathematics. On the one hand, Voevodsky's subtle and…

Logic · Mathematics 2013-08-06 The Univalent Foundations Program

The study of homotopy theoretic phenomena in the language of type theory is sometimes loosely called `synthetic homotopy theory'. Homotopy theory in type theory is only one of the many aspects of homotopy type theory, which also includes…

Logic · Mathematics 2019-06-25 Egbert Rijke

$\infty$-category theory was originally developed in the context of classical homotopy theory using standard set theoretical assumptions, but has since been extended to a variety of mathematical foundations. One such successful effort,…

Category Theory · Mathematics 2025-08-13 Nima Rasekh

Homotopy Type Theory is a new field of mathematics based on the surprising and elegant correspondence between Martin-Lofs constructive type theory and abstract homotopy theory. We have a powerful interplay between these disciplines - we can…

Logic in Computer Science · Computer Science 2014-02-10 Kristina Sojakova

We recapture Douglas' framework for twisted parametrized stable homotopy theory in the language of $\infty$- categories. A twisted spectrum is essentially a section of a bundle of presentable stable $\infty$-categories whose fiber is the…

Algebraic Topology · Mathematics 2025-12-24 Alice Hedenlund , Tasos Moulinos

We combine Homotopy Type Theory with axiomatic cohesion, expressing the latter internally with a version of "adjoint logic" in which the discretization and codiscretization modalities are characterized using a judgmental formalism of "crisp…

Category Theory · Mathematics 2017-04-26 Michael Shulman

This is an introductory textbook to univalent mathematics and homotopy type theory, a mathematical foundation that takes advantage of the structural nature of mathematical definitions and constructions. It is common in mathematical practice…

Logic · Mathematics 2022-12-22 Egbert Rijke

We develop a dependent type theory that is based purely on inductive and coinductive types, and the corresponding recursion and corecursion principles. This results in a type theory with a small set of rules, while still being fairly…

Logic in Computer Science · Computer Science 2016-05-10 Henning Basold , Herman Geuvers

We consider the problem of defining the integers in Homotopy Type Theory (HoTT). We can define the type of integers as signed natural numbers (i.e., using a coproduct), but its induction principle is very inconvenient to work with, since it…

Logic in Computer Science · Computer Science 2020-07-02 Thorsten Altenkirch , Luis Scoccola

We propose a new bi-intuitionistic type theory called Dualized Type Theory (DTT). It is a simple type theory with perfect intuitionistic duality, and corresponds to a single-sided polarized sequent calculus. We prove DTT strongly…

Logic in Computer Science · Computer Science 2019-03-14 Harley Eades , Aaron Stump , Ryan McCleeary

The main goal of the present paper is the construction of twisted generalized differential cohomology theories and the comprehensive statement of its basic functorial properties. Technically it combines the homotopy theoretic approach to…

Algebraic Topology · Mathematics 2019-08-21 Ulrich Bunke , Thomas Nikolaus

We show that contrary to appearances, Multimodal Type Theory (MTT) over a 2-category M can be interpreted in any M-shaped diagram of categories having, and functors preserving, M-sized limits, without the need for extra left adjoints. This…

Category Theory · Mathematics 2024-02-14 Michael Shulman

This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of…

Logic in Computer Science · Computer Science 2017-10-09 Lars Birkedal , Aleš Bizjak , Ranald Clouston , Hans Bugge Grathwohl , Bas Spitters , Andrea Vezzosi

We present a new way to control the unfolding of definitions in dependent type theory. Traditionally, proof assistants require users to fix whether each definition will or will not be unfolded in the remainder of a development; unfolding…

Logic in Computer Science · Computer Science 2025-10-16 Daniel Gratzer , Jonathan Sterling , Carlo Angiuli , Thierry Coquand , Lars Birkedal