2-natural transformation?
Recall that in a category , each pair of objects and determines a set , the hom-set of and . In a -category , each pair of objects determines a category . This category is the hom-category of and .
As a -category is enriched over Cat, a hom-category is a special case of a hom-object. But the hom-category makes sense also for the weakly enriched concept of bicategory.
hom-category