Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Apply unknownprop_eb8e8f72a91f1b934993d4cb19c84c8270f73a3626f3022b683d960a7fef89cb with
x0 = x1,
x0 = x2.
Apply unknownprop_0d3ad3213d576718836e056704a48c63c61784b4520d1b5b45f18fbf3cb09962 with
x0,
x1,
x2.
The subproof is completed by applying H0.