{C : Type u₁} →
  [inst : CategoryTheory.Category.{v₁, u₁} C] →
    {X Y : C} →
      {f : X ⟶ Y} →
        {motive : CategoryTheory.RegularMono f → Sort u} →
          (t : CategoryTheory.RegularMono f) →
            ((Z : C) →
                (left right : Y ⟶ Z) →
                  (w : CategoryTheory.CategoryStruct.comp f left = CategoryTheory.CategoryStruct.comp f right) →
                    (isLimit : CategoryTheory.Limits.IsLimit (CategoryTheory.Limits.Fork.ofι f w)) →
                      motive { Z := Z, left := left, right := right, w := w, isLimit := isLimit }) →
              motive t