Let x0 of type ι be given.
Let x1 of type ι → ι → ι be given.
Let x2 of type ι → ι → ο be given.
Apply unknownprop_f31eb2228dfee2fe4dd27f9052dc9bb4b4e8eea40ff1d87c4fda262a65a942a4 with
b5cc3.. x0 x1 x2,
x0,
x1,
x2.
Let x3 of type ι → ι → ο be given.
The subproof is completed by applying H0.