Homotopy-Initial Algebras in Type Theory

Abstract

We investigate inductive types in type theory, using the insights provided by homotopy type theory and univalent foundations of mathematics. We do so by introducing the new notion of a homotopy-initial algebra. This notion is defined by a purely type-theoretic contractibility condition that replaces the standard, category-theoretic universal property involving the existence and uniqueness of appropriate morphisms. Our main result characterizes the types that are equivalent to W-types as homotopy-initial algebras.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jan 30, 2017
Source ID
10.1145/3006383

Entities

People

  • Kristina Sojakova
  • Nicola Gambino
  • Steve Awodey

Organizations

  • Air Force Research Laboratory
  • Army Research Office
  • Carnegie Mellon University
  • Engineering and Physical Sciences Research Council
  • John Templeton Foundation
  • National Science Foundation
  • University of Leeds

Tags

Fields of Study

  • Mathematics

Readers

  • Mathematical Modeling and Probability Theory.