English
For any p ∈ GroupNorm E, the underlying function of p.toGroupSeminorm equals p; i.e., the coe toGroupSeminorm recovers p.
Русский
Для любого p ∈ GroupNorm E базовая функция p.toGroupSeminorm равна p; то есть приведение кGroupSeminorm восстанавливает p.
LaTeX
$$$ \forall x, (p.toGroupSeminorm)(x) = p(x) $$$
Lean4
theorem smul_sup (r : R) (p q : GroupSeminorm E) : r • (p ⊔ q) = r • p ⊔ r • q :=
have Real.smul_max : ∀ x y : ℝ, r • max x y = max (r • x) (r • y) := fun x y => by
simpa only [← smul_eq_mul, ← NNReal.smul_def, smul_one_smul ℝ≥0 r (_ : ℝ)] using
mul_max_of_nonneg x y (r • (1 : ℝ≥0) : ℝ≥0).coe_nonneg
ext fun _ => Real.smul_max _ _