English
A lemma about equality of recursive definitions in Prod.GameAdd.
Русский
Лемма о равенстве рекурсивных определений в Prod.GameAdd.
LaTeX
$$$\\text{fix\_eq}$$$
Lean4
theorem fix_eq {C : α → β → Sort*} (hα : WellFounded rα) (hβ : WellFounded rβ)
(IH : ∀ a₁ b₁, (∀ a₂ b₂, GameAdd rα rβ (a₂, b₂) (a₁, b₁) → C a₂ b₂) → C a₁ b₁) (a : α) (b : β) :
GameAdd.fix hα hβ IH a b = IH a b fun a' b' _ => GameAdd.fix hα hβ IH a' b' :=
WellFounded.fix_eq _ _ _