∀ {R : Type u_3} {𝕜 : Type u_1} {E : Type u_2} [inst : SeminormedRing 𝕜] [inst_1 : AddGroup E] [inst_2 : SMul 𝕜 E]
  [inst_3 : Monoid R] [inst_4 : DistribMulAction R ℝ] [inst_5 : SMul R NNReal] [inst_6 : IsScalarTower R NNReal ℝ]
  (c : R) (x : Seminorm 𝕜 E), (Seminorm.coeFnAddMonoidHom 𝕜 E) (c • x) = c • (Seminorm.coeFnAddMonoidHom 𝕜 E) x