• Title of article

    Wellfounded trees in categories Original Research Article

  • Author/Authors

    Ieke Moerdijk، نويسنده , , Erik Palmgren، نويسنده ,

  • Issue Information
    روزنامه با شماره پیاپی سال 2000
  • Pages
    30
  • From page
    189
  • To page
    218
  • Abstract
    In this paper we present and study a categorical formulation of the W-types of Martin-Löf. These are essentially free term algebras where the operations may have finite or infinite arity. It is shown that W-types are preserved under the construction of sheaves and Artin gluing. In the proofs we avoid using impredicative or nonconstructive principles.
  • Keywords
    Initial algebras , Pretoposes , Artin gluing , Sheaves , Wellfounded trees , Martin-L?f type theory , Locally cartesian closed categories
  • Journal title
    Annals of Pure and Applied Logic
  • Serial Year
    2000
  • Journal title
    Annals of Pure and Applied Logic
  • Record number

    889730