The evaluation map

Let S be a fixed set. For each set X, let XS denote the set of all functions h:S→X in Set.

  1. Show that X↦XS is the object function of a functor Set→Set.
  2. Show that X↦XS×S is the object function of a functor Set→Set.
  3. For each set X let eX:XS×S→X be the evaluation map, defined by e(h,s)=h(s). Show that these maps are the components of a natural transformation e:∙S×S⇒I, where I is the identity functor on Set.