Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Apply unknownprop_b456609235d152f08bccfce314d541d7c44f3716137c00b0ce21cf467ba83d17 with
4ae4a.. (4ae4a.. (4ae4a.. 4a7ef..)),
λ x3 . If_i (x3 = 4a7ef..) x0 (If_i (x3 = 4ae4a.. 4a7ef..) x1 x2),
4a7ef..,
λ x3 x4 . x4 = x0 leaving 2 subgoals.
The subproof is completed by applying unknownprop_908178e99fde3dae62c02b64ea0c0ee3bf2c0e09b3da64c73a5307a7bb9c1e9e.