Reason isomorphically!

  • Authors:
  • Ralf Hinze;Daniel W.H. James

  • Affiliations:
  • University of Oxford, Oxford, United Kingdom;University of Oxford, Oxford, United Kingdom

  • Venue:
  • Proceedings of the 6th ACM SIGPLAN workshop on Generic programming
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

When are two types the same? In this paper we argue that isomorphism is a more useful notion than equality. We explain a succinct and elegant approach to establishing isomorphisms, with our focus on showing their existence over deriving the witnesses. We use category theory as a framework, but rather than chasing diagrams or arguing with arrows, we present our proofs in a calculational style. In particular, we hope to showcase to the reader why the Yoneda lemma and adjunctions should be in their reasoning toolbox.