English
A variant of isometry result for lp.single holds in contexts where a 1 ≤ p assumption is available, ensuring norm preservation.
Русский
Вариант результата изометрии для lp.single сохраняет норму при предпосылке 1 ≤ p.
LaTeX
$$$\text{Isometry}(\text{lp.single } p i)$ (when suitable).$$
Lean4
theorem isometry_single [Fact (1 ≤ p)] (i : α) : Isometry (lp.single (E := E) p i) :=
AddMonoidHomClass.isometry_of_norm (lp.singleAddMonoidHom (E := E) p i) fun _ ↦
lp.norm_single (zero_lt_one.trans_le Fact.out) _ _