Proof irrelevance and subset types

  • Martin Hofmann
Part of the CPHC/BCS Distinguished Dissertations book series (DISTDISS)


Our aim in this chapter is to present a syntactic model for the extensional constructs of proof irrelevance and subset types. The model we give not only provides these concepts, but also relates two approaches to program development in Martin-Löf type theory [88] or the Extended Calculus of Constructions (ECC) [68]. Under the first one specifications and types are freely mixed using -types. This methodology underpins a project for development of correct software at the University of Ulm [112]. It is also the most natural approach and is probably employed by most users of type systems like the ones under consideration.


Type Theory Syntactic Category Equality Rule Equality Judgement Refined Type 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag London Limited 1997

Authors and Affiliations

  • Martin Hofmann
    • 1
  1. 1.Fachbereich MathematikTechnische Hochschule DarmstadtDarmstadtGermany

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