English
If f lies in Memℓp, then its star, star f, also lies in Memℓp.
Русский
Если f принадлежит Memℓp, то и star f принадлежит Memℓp.
LaTeX
$$$Mem\\ell p (star f) p\\;\\Rightarrow\\; Mem\\ell p f p$ and $Mem\\ell p (star f) p$$$
Lean4
theorem _root_.Memℓp.star_mem {f : ∀ i, E i} (hf : Memℓp f p) : Memℓp (star f) p :=
by
rcases p.trichotomy with (rfl | rfl | hp)
· apply memℓp_zero
simp [hf.finite_dsupport]
· apply memℓp_infty
simpa using hf.bddAbove
· apply memℓp_gen
simpa using hf.summable hp