Library CT.Instance.Functor.FullFunctor
Full Functors
A "full" functor is one that is surjective on hom-sets. That is,
A functor \(F : C \to D\) is
full if \(\forall x, y \in C\), the function
\(F : C(x, y) \to D(F(x), F(y))\) is surjective.
So we require a
Functor and a proof that surjectivity of hom-sets is
satisfied.