Let x0 of type ι be given.
Let x1 of type ι be given.
Apply SNoLev_ind with
λ x2 . SNoLev x2 ∈ SNoLev (add_SNo x0 x1) ⟶ SNoLt x2 (add_SNo x0 x1) ⟶ or (∃ x3 . and (x3 ∈ SNoL x0) (SNoLe x2 (add_SNo x3 x1))) (∃ x3 . and (x3 ∈ SNoL x1) (SNoLe x2 (add_SNo x0 x3))).
Let x2 of type ι be given.
Apply dneg with
or (∃ x3 . and (x3 ∈ SNoL x0) (SNoLe x2 (add_SNo x3 x1))) (∃ x3 . and (x3 ∈ SNoL x1) (SNoLe x2 (add_SNo x0 x3))).
Apply SNoLt_irref with
x2.
Apply SNoLtLe_tra with
x2,
add_SNo x0 x1,
x2 leaving 5 subgoals.
The subproof is completed by applying H3.
The subproof is completed by applying L2.
The subproof is completed by applying H3.
The subproof is completed by applying H6.
Apply add_SNo_eq with
x0,
x1,
λ x3 x4 . SNoLe x4 x2 leaving 3 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
Let x2 of type ι be given.
Apply SNoL_E with
add_SNo x0 x1,
x2,
or (∃ x3 . and (x3 ∈ SNoL x0) (SNoLe x2 (add_SNo x3 x1))) (∃ x3 . and (x3 ∈ SNoL x1) (SNoLe x2 (add_SNo x0 x3))) leaving 3 subgoals.
The subproof is completed by applying L2.
The subproof is completed by applying H4.
Apply L3 with
x2 leaving 3 subgoals.
The subproof is completed by applying H5.
The subproof is completed by applying H6.
The subproof is completed by applying H7.