Let x0 of type ι be given.
Let x1 of type ι be given.
Apply add_SNo_add_CSNo with
x0,
x1,
λ x2 x3 . x2 ∈ int leaving 3 subgoals.
Apply int_SNo with
x0.
The subproof is completed by applying H0.
Apply int_SNo with
x1.
The subproof is completed by applying H1.
Apply int_add_SNo with
x0,
x1 leaving 2 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.