Diagonal functor
Functor
context | C,D … category |
definiendum | Δ:C⟶CD |
definition | ΔC:=ΔC |
definition | Δ(f):=constf |
Discussion
Coherence
Note that for constant functors ΔA,ΔB, the square in the definition of a natural transformation commutes trivially. Hence any arrow f:C[A,B] gives rise to a natural transformation.
Reference
Wikipedia: Diagonal functor
nLab: Diagonal functor