∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.Preadditive C] {X Y : C}
  {t : CategoryTheory.Limits.Cone (CategoryTheory.Limits.pair X Y)} (ht : CategoryTheory.Limits.IsLimit t),
  CategoryTheory.CategoryStruct.comp
      (CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.BinaryBicone.ofLimitCone ht).fst
          (CategoryTheory.Limits.BinaryBicone.ofLimitCone ht).inl +
        CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.BinaryBicone.ofLimitCone ht).snd
          (CategoryTheory.Limits.BinaryBicone.ofLimitCone ht).inr)
      (CategoryTheory.Limits.BinaryFan.fst t) =
    CategoryTheory.CategoryStruct.comp
      (CategoryTheory.CategoryStruct.id (CategoryTheory.Limits.BinaryBicone.ofLimitCone ht).pt)
      (CategoryTheory.Limits.BinaryFan.fst t)