Let x0 of type ι → (ι → ι → ι) → ι → ι be given.
Assume H0:
∀ x1 . ∀ x2 x3 : ι → ι → ι . (∀ x4 . prim1 x4 x1 ⟶ x2 x4 = x3 x4) ⟶ x0 x1 x2 = x0 x1 x3.
Let x1 of type ι be given.
Apply In_rec_G_ii_f with
x0,
x1,
In_rec_ii x0 x1,
x0 x1 (In_rec_ii x0) leaving 3 subgoals.
The subproof is completed by applying H0.
Apply In_rec_G_ii_In_rec_ii with
x0,
x1.
The subproof is completed by applying H0.
Apply In_rec_G_ii_In_rec_ii_d with
x0,
x1.
The subproof is completed by applying H0.