Models of Type Theory Based on Moore Paths
Published version
Peer-reviewed
Repository URI
Repository DOI
Change log
Authors
Orton, RI
Pitts, AM
Abstract
This paper introduces a new family of models of intensional Martin-Löf type theory. We use constructive ordered algebra in toposes. Identity types in the models are given by a notion of Moore path. By considering a particular gros topos, we show that there is such a model that is non-truncated, i.e. contains non-trivial structure at all dimensions. In other words, in this model a type in a nested sequence of identity types can contain more than one element, no matter how great the degree of nesting. Although inspired by existing non-truncated models of type theory based on simplicial and on cubical sets, the notion of model presented here is notable for avoiding any form of Kan filling condition in the semantics of types.
Description
Keywords
dependent type theory, homotopy theory, Moore path, topos
Journal Title
LIPIcs : Leibniz International Proceedings in Informatics
Conference Name
2nd International Conference on Formal Structures for Computation and Deduction (FSCD 2017)
Journal ISSN
1868-8969
1860-5974
1860-5974
Volume Title
Publisher
Schloss Dagstuhl -- Leibniz-Zentrum fuer Informatik
Publisher DOI
Sponsorship
EPSRC (1641673)
EPSRC Studentship