Reflective Subcategory

A reflective subcategory of a Category 𝒟 𝒟 \mathcal{D} is a category 𝒞 𝒞 \mathcal{C} equipped with a Fully Faithful Functor ι : 𝒞 𝒟 : 𝜄 𝒞 𝒟 \iota:\mathcal{C}\to\mathcal{D} that has a Left Adjoint T 𝑇 T .

Examples