English
Equality between strongDownwardInductionOn s and the corresponding H-form holds.
Русский
Справедливость равенства между strongDownwardInductionOn и соответствующим H-образованием.
LaTeX
$$$\\text{strongDownwardInductionOn}(s) = H\\,s(\\lambda t, h => \\text{strongDownwardInductionOn}(t))$$$
Lean4
theorem strongDownwardInductionOn_eq {p : Finset α → Sort*} (s : Finset α)
(H : ∀ t₁, (∀ {t₂ : Finset α}, #t₂ ≤ n → t₁ ⊂ t₂ → p t₂) → #t₁ ≤ n → p t₁) :
s.strongDownwardInductionOn H = H s fun {t} ht _ => t.strongDownwardInductionOn H ht :=
by
dsimp only [strongDownwardInductionOn]
rw [strongDownwardInduction]