†-category: Rel

Rel is a †-category. Composition in Rel can happen in either direction; every arrow can interchange its source and target objects freely.

The core of Rel is the groupoid SymmRel:

Core(Rel) ≅ SymmRel

The unitary arrows of Rel are the arrows of SymmRel; they are symmetric relations.

dagger_categories: Rel

This data as json

category
Rel