English

A categorical formulation of Kraus' paradox

Category Theory 2024-03-28 v1 Logic in Computer Science Logic

Abstract

We give a categorical formulation of Kraus' "magic trick" for recovering information from truncated types. Rather than type theory, we work in Van den Berg-Moerdijk path categories with a univalent universe, and rather than propositional truncation we work with arbitrary cofibrations, which includes truncation as a special case. We show, using Kraus' argument that any cofibration with homogeneous domain is a monomorphism. We give some simple concrete examples in groupoids to illustrate the interaction between homogeneous types, cofibrations and univalent fibrations.

Keywords

Cite

@article{arxiv.2403.17961,
  title  = {A categorical formulation of Kraus' paradox},
  author = {Andrew W. Swan},
  journal= {arXiv preprint arXiv:2403.17961},
  year   = {2024}
}