English
For a subsingleton index, the difference f(m1) - f(m2) is bounded by a quantity linear in ||f|| and a sum of products of the norms of m.
Русский
Для подмножества индексов норма разности f(m1) - f(m2) ограничена величиной, пропорциональной ||f||, и суммой произведений норм элементов m.
LaTeX
$$$\|f(m_1) - f(m_2)\| \le \|f\| \cdot \sum_i \prod_j \big(\|m_{1,i} - m_{2,i}\|^{\delta_{j,i}} \cdot \max(\|m_{1,j}\|,\|m_{2,j}\|)^{1-\delta_{j,i}}\big)$$$
Lean4
/-- `constOfIsEmpty` as a linear isometry equivalence. -/
@[simps]
def constOfIsEmptyLIE [IsEmpty ι] : F ≃ₗᵢ[𝕜] (E [⋀^ι]→L[𝕜] F)
where
toFun := constOfIsEmpty _ _ _
invFun f := f 0
left_inv x := by simp
right_inv f := by ext x; simp [Subsingleton.allEq x 0]
map_add' f g := rfl
map_smul' c f := rfl
norm_map' := norm_constOfIsEmpty _ _