Cores: FinSet
The category FinSet has the groupoid Perm as its core, or maximal subcategory which is still a groupoid. As with all cores, Perm is an (essentially) wide subcategory of FinSet.
There is a functor from categories to groupoids:
Core : Cat → Grpd
And it sends FinSet to Perm:
Core : FinSet ↦ Perm
Core(FinSet) ≅ Perm
cores: FinSet
This data as json
| groupoid | category |
|---|---|
| Perm | FinSet |