Search Results

Documents authored by Van Muylder, Antoine


Document
Nominal Type Theory by Nullary Internal Parametricity

Authors: Antoine Van Muylder, Andreas Nuyts, and Dominique Devriese

Published in: LIPIcs, Volume 384, 31st International Conference on Types for Proofs and Programs (TYPES 2025)


Abstract
There are many ways to represent the syntax of a language with binders. In particular, nominal frameworks are metalanguages that feature (among others) name abstraction types, which can be used to specify the type of binders. The resulting syntax representation, nominal data types, makes alpha-equivalent terms equal, has a closed induction principle and is well-behaved w.r.t. weakening. It is known that name abstraction types can be presented either as an existential or as a universal quantification on names. Existential name abstractions support matching on name-binding patterns but have cumbersome typing rules; universal ones have clean rules but apparently no such nominal matching. In this work we show that this matching ability and other nominal features are recovered in a type theory consisting of (1) Nullary (0-ary) Internally Parametric Type Theory (nullary PTT), (2) a type of names and a novel name induction principle, (3) nominal data types. This type theory is a legitimate nominal framework: it has universal and (non-primitive) existential name abstractions, a freshness type former, restricted name swapping and local-scope operations. Nominal pattern matching is recovered via term-relevant nullary parametricity. We provide an example involving synthetic Kripke parametricity.

Cite as

Antoine Van Muylder, Andreas Nuyts, and Dominique Devriese. Nominal Type Theory by Nullary Internal Parametricity. In 31st International Conference on Types for Proofs and Programs (TYPES 2025). Leibniz International Proceedings in Informatics (LIPIcs), Volume 384, pp. 12:1-12:23, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2026)


Copy BibTex To Clipboard

@InProceedings{vanmuylder_et_al:LIPIcs.TYPES.2025.12,
  author =	{Van Muylder, Antoine and Nuyts, Andreas and Devriese, Dominique},
  title =	{{Nominal Type Theory by Nullary Internal Parametricity}},
  booktitle =	{31st International Conference on Types for Proofs and Programs (TYPES 2025)},
  pages =	{12:1--12:23},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-441-3},
  ISSN =	{1868-8969},
  year =	{2026},
  volume =	{384},
  editor =	{Nordvall Forsberg, Fredrik and McKinna, James},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.TYPES.2025.12},
  URN =		{urn:nbn:de:0030-drops-270300},
  doi =		{10.4230/LIPIcs.TYPES.2025.12},
  annote =	{Keywords: Nominal techniques, Parametricity}
}
Any Issues?
X

Feedback on the Current Page

CAPTCHA

Thanks for your feedback!

Feedback submitted to Dagstuhl Publishing

Could not send message

Please try again later or send an E-mail