English

Coherence for Skew-Monoidal Categories

Logic in Computer Science 2014-08-26 v1 Programming Languages Category Theory

Abstract

I motivate a variation (due to K. Szlach\'{a}nyi) of monoidal categories called skew-monoidal categories where the unital and associativity laws are not required to be isomorphisms, only natural transformations. Coherence has to be formulated differently than in the well-known monoidal case. In my (to my knowledge new) version, it becomes a statement of uniqueness of normalizing rewrites. I present a proof of this coherence theorem and also formalize it fully in the dependently typed programming language Agda.

Keywords

Cite

@article{arxiv.1406.2064,
  title  = {Coherence for Skew-Monoidal Categories},
  author = {Tarmo Uustalu},
  journal= {arXiv preprint arXiv:1406.2064},
  year   = {2014}
}

Comments

In Proceedings MSFP 2014, arXiv:1406.1534

R2 v1 2026-06-22T04:33:40.880Z