∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] (X : C)
  [inst_1 : CategoryTheory.Limits.HasBinaryProducts C] {X_1 Y Z : CategoryTheory.Over X} (f : X_1 ⟶ Y) (g : Y ⟶ Z),
  { f := (CategoryTheory.CategoryStruct.comp f g).left, h := ⋯ } =
    CategoryTheory.CategoryStruct.comp { f := f.left, h := ⋯ } { f := g.left, h := ⋯ }