The continuity of monadic stream functions

Brouwer’s continuity principle states that all functions from infinite sequences of naturals to naturals are continuous, that is, for every sequence the result depends only on a finite initial segment. It is an intuitionistic axiom that is incompatible with classical mathematics. Recently Mart́ín Es...

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Main Authors: Capretta, Venanzio, Fowler, Jonathan
Format: Article
Published: ACM 2017
Subjects:
Online Access:https://eprints.nottingham.ac.uk/46420/
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author Capretta, Venanzio
Fowler, Jonathan
author_facet Capretta, Venanzio
Fowler, Jonathan
author_sort Capretta, Venanzio
building Nottingham Research Data Repository
collection Online Access
description Brouwer’s continuity principle states that all functions from infinite sequences of naturals to naturals are continuous, that is, for every sequence the result depends only on a finite initial segment. It is an intuitionistic axiom that is incompatible with classical mathematics. Recently Mart́ín Escardó proved that it is also inconsistent in type theory. We propose a reformulation of the continuity principle that may be more faithful to the original meaning by Brouwer. It applies to monadic streams, potentially unending sequences of values produced by steps triggered by a monadic action, possibly involving side effects. We consider functions on them that are uniform, in the sense that they operate in the same way independently of the particular monad that provides the specific side effects. Formally this is done by requiring a form of naturality in the monad. Functions on monadic streams have not only a foundational importance, but have also practical applications in signal processing and reactive programming. We give algorithms to determine the modulus of continuity of monadic stream functions and to generate dialogue trees for them (trees whose nodes and branches describe the interaction of the process with the environment).
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spelling nottingham-464202020-05-04T19:01:07Z https://eprints.nottingham.ac.uk/46420/ The continuity of monadic stream functions Capretta, Venanzio Fowler, Jonathan Brouwer’s continuity principle states that all functions from infinite sequences of naturals to naturals are continuous, that is, for every sequence the result depends only on a finite initial segment. It is an intuitionistic axiom that is incompatible with classical mathematics. Recently Mart́ín Escardó proved that it is also inconsistent in type theory. We propose a reformulation of the continuity principle that may be more faithful to the original meaning by Brouwer. It applies to monadic streams, potentially unending sequences of values produced by steps triggered by a monadic action, possibly involving side effects. We consider functions on them that are uniform, in the sense that they operate in the same way independently of the particular monad that provides the specific side effects. Formally this is done by requiring a form of naturality in the monad. Functions on monadic streams have not only a foundational importance, but have also practical applications in signal processing and reactive programming. We give algorithms to determine the modulus of continuity of monadic stream functions and to generate dialogue trees for them (trees whose nodes and branches describe the interaction of the process with the environment). ACM 2017-08-18 Article PeerReviewed Capretta, Venanzio and Fowler, Jonathan (2017) The continuity of monadic stream functions. Proceedings of the 32nd Annual ACM/IEEE Symposium on Logic in Computer Science, LICS '17 . pp. 1-12. ISSN 1043-6871 monadic stream function continuity type theory functional programming stream monad dialogue trees strategy trees http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=7999337 doi:10.1109/LICS.2017.8005119 doi:10.1109/LICS.2017.8005119
spellingShingle monadic stream function
continuity
type theory functional programming
stream
monad
dialogue trees
strategy trees
Capretta, Venanzio
Fowler, Jonathan
The continuity of monadic stream functions
title The continuity of monadic stream functions
title_full The continuity of monadic stream functions
title_fullStr The continuity of monadic stream functions
title_full_unstemmed The continuity of monadic stream functions
title_short The continuity of monadic stream functions
title_sort continuity of monadic stream functions
topic monadic stream function
continuity
type theory functional programming
stream
monad
dialogue trees
strategy trees
url https://eprints.nottingham.ac.uk/46420/
https://eprints.nottingham.ac.uk/46420/
https://eprints.nottingham.ac.uk/46420/