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Mathlib.CategoryTheory.Functor.Hom

The hom functor, sending (X, Y) to the type X ⟶ Y.

@[simp]
theorem CategoryTheory.Functor.hom_map (C : Type u) [CategoryTheory.Category.{v, u} C] :
∀ {X Y : Cᵒᵖ × C} (f : X Y) (h : X.1.unop X.2), (CategoryTheory.Functor.hom C).toPrefunctor.map f h = CategoryTheory.CategoryStruct.comp f.1.unop (CategoryTheory.CategoryStruct.comp h f.2)
@[simp]
theorem CategoryTheory.Functor.hom_obj (C : Type u) [CategoryTheory.Category.{v, u} C] (p : Cᵒᵖ × C) :
(CategoryTheory.Functor.hom C).toPrefunctor.obj p = (p.1.unop p.2)

Functor.hom is the hom-pairing, sending (X, Y) to X ⟶ Y, contravariant in X and covariant in Y.

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