Free higher groups in homotopy type theory

Given a type A in homotopy type theory (HoTT), we can define the free ∞-group on A as the higher inductive type F (A)with constructors unit: F(A),cons : A → F(A) → F(A), and conditions saying that every cons(a)is an auto-equivalence on F(A). Equivalently, we can take the loop space of the suspension...

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Main Authors: Kraus, Nicolai, Altenkirch, Thorsten
Format: Conference or Workshop Item
Language:English
Published: 2018
Online Access:https://eprints.nottingham.ac.uk/51212/
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author Kraus, Nicolai
Altenkirch, Thorsten
author_facet Kraus, Nicolai
Altenkirch, Thorsten
author_sort Kraus, Nicolai
building Nottingham Research Data Repository
collection Online Access
description Given a type A in homotopy type theory (HoTT), we can define the free ∞-group on A as the higher inductive type F (A)with constructors unit: F(A),cons : A → F(A) → F(A), and conditions saying that every cons(a)is an auto-equivalence on F(A). Equivalently, we can take the loop space of the suspension of A + 1. Assuming that A is a set (i.e. satisfies the principle of unique identity proofs), we are interested in the question whether F(A) is a set as well, which is very much related to an open problem in the HoTT book [20, Ex. 8.2]. We show an approximation to the question, namely that the fundamental groups of F(A) are trivial, i.e. that ∥F(A)∥1 is a set.
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spelling nottingham-512122018-09-20T10:13:16Z https://eprints.nottingham.ac.uk/51212/ Free higher groups in homotopy type theory Kraus, Nicolai Altenkirch, Thorsten Given a type A in homotopy type theory (HoTT), we can define the free ∞-group on A as the higher inductive type F (A)with constructors unit: F(A),cons : A → F(A) → F(A), and conditions saying that every cons(a)is an auto-equivalence on F(A). Equivalently, we can take the loop space of the suspension of A + 1. Assuming that A is a set (i.e. satisfies the principle of unique identity proofs), we are interested in the question whether F(A) is a set as well, which is very much related to an open problem in the HoTT book [20, Ex. 8.2]. We show an approximation to the question, namely that the fundamental groups of F(A) are trivial, i.e. that ∥F(A)∥1 is a set. 2018-07-09 Conference or Workshop Item PeerReviewed application/pdf en https://eprints.nottingham.ac.uk/51212/1/root_lics_fg.pdf Kraus, Nicolai and Altenkirch, Thorsten (2018) Free higher groups in homotopy type theory. In: 33rd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS), 9–12 July 2018, Oxford, England. https://dl.acm.org/citation.cfm?id=3209183
spellingShingle Kraus, Nicolai
Altenkirch, Thorsten
Free higher groups in homotopy type theory
title Free higher groups in homotopy type theory
title_full Free higher groups in homotopy type theory
title_fullStr Free higher groups in homotopy type theory
title_full_unstemmed Free higher groups in homotopy type theory
title_short Free higher groups in homotopy type theory
title_sort free higher groups in homotopy type theory
url https://eprints.nottingham.ac.uk/51212/
https://eprints.nottingham.ac.uk/51212/