∀ {J : Type v} [inst : CategoryTheory.Category.{w, v} J] (F : CategoryTheory.Functor J GrpCat)
  [inst_1 : Small.{u, max u v} ↑(F.comp (CategoryTheory.forget GrpCat)).sections],
  GrpCat.limitGroup F = inferInstanceAs (Group (Shrink.{u, max u v} ↑(F.comp (CategoryTheory.forget GrpCat)).sections))