Apply ordinal_ind to the current goal.
Let alpha be given.
Assume Ha: ordinal alpha.
Apply ordinal_ind to the current goal.
Let beta be given.
Assume Hb: ordinal beta.
Let x be given.
Let y be given.
Apply SNoS_E2 alpha Ha x Hx to the current goal.
Apply SNoS_E2 beta Hb y Hy to the current goal.
Apply H1 x y Hx3 Hy3 to the current goal.
Let w be given.
An
exact proof term for the current goal is
IHa (SNoLev x) Hx1 beta Hb w Hw y Hy.
An
exact proof term for the current goal is
IHb (SNoLev y) Hy1 x Hx.
Let w be given.
Let z be given.
An
exact proof term for the current goal is
IHa (SNoLev x) Hx1 (SNoLev y) Hy2 w Hw z Hz.