∀ (K : Type u_1) [inst : CommRing K] [inst_1 : IsDomain K] (R : Type u_2) [inst_2 : CommSemiring R]
  [inst_3 : Algebra R (Polynomial K)] (c : R) (x : RatFunc K),
  c • x =
    { toFun := fun x => RatFunc.mk ((algebraMap R (Polynomial K)) x) 1, map_one' := ⋯, map_mul' := ⋯, map_zero' := ⋯,
          map_add' := ⋯ }
        c *
      x