subcategory,supercategory,kind
Bij,Set,core
FinOrd,FinSet,skeleton
Hilb₀,Hilb,core
Inj,Set,essentially wide
Mat_k,FinVect_k,skeleton
Perm,FinSet,core
Pfn,Rel,essentially wide
Pos,Pros,skeleton
Set,Pfn,total restriction
Surj,Set,essentially wide
SymmRel,Rel,core
Top,AdmRep,total restriction