Let P be given.
Assume H1: ∀x y, SNo xSNo y(∀wSNoS_ (SNoLev x), P w y)(∀zSNoS_ (SNoLev y), P x z)(∀wSNoS_ (SNoLev x), ∀zSNoS_ (SNoLev y), P w z)P x y.
We prove the intermediate claim L1: ∀alpha, ordinal alpha∀beta, ordinal beta∀xSNoS_ alpha, ∀ySNoS_ beta, P x y.
Apply ordinal_ind to the current goal.
Let alpha be given.
Assume Ha: ordinal alpha.
Assume IHa: ∀gammaalpha, ∀beta, ordinal beta∀xSNoS_ gamma, ∀ySNoS_ beta, P x y.
Apply ordinal_ind to the current goal.
Let beta be given.
Assume Hb: ordinal beta.
Assume IHb: ∀deltabeta, ∀xSNoS_ alpha, ∀ySNoS_ delta, P x y.
Let x be given.
Assume Hx: x SNoS_ alpha.
Let y be given.
Assume Hy: y SNoS_ beta.
Apply SNoS_E2 alpha Ha x Hx to the current goal.
Assume Hx1: SNoLev x alpha.
Assume Hx2: ordinal (SNoLev x).
Assume Hx3: SNo x.
Assume Hx4: SNo_ (SNoLev x) x.
Apply SNoS_E2 beta Hb y Hy to the current goal.
Assume Hy1: SNoLev y beta.
Assume Hy2: ordinal (SNoLev y).
Assume Hy3: SNo y.
Assume Hy4: SNo_ (SNoLev y) y.
Apply H1 x y Hx3 Hy3 to the current goal.
We will prove ∀wSNoS_ (SNoLev x), P w y.
Let w be given.
Assume Hw: w SNoS_ (SNoLev x).
An exact proof term for the current goal is IHa (SNoLev x) Hx1 beta Hb w Hw y Hy.
We will prove ∀zSNoS_ (SNoLev y), P x z.
An exact proof term for the current goal is IHb (SNoLev y) Hy1 x Hx.
We will prove ∀wSNoS_ (SNoLev x), ∀zSNoS_ (SNoLev y), P w z.
Let w be given.
Assume Hw: w SNoS_ (SNoLev x).
Let z be given.
Assume Hz: z SNoS_ (SNoLev y).
An exact proof term for the current goal is IHa (SNoLev x) Hx1 (SNoLev y) Hy2 w Hw z Hz.
An exact proof term for the current goal is SNo_ordinal_ind2 P L1.