Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Let x3 of type ι be given.
Apply unknownprop_3647185bee823f297472e9b1979bff6804bdede7c0824747eee03864f4f342a6 with
λ x4 x5 : ι → ι → ι → ο . x5 x0 x1 x2 ⟶ x5 x0 x2 x3 ⟶ x5 x0 x1 x3.
The subproof is completed by applying unknownprop_e0f34743af27a604447ff8f709ee0ab4cfc998bf21a330579a3abf15b483f3e6 with
x0,
λ x4 . In x4 x1,
λ x4 . In x4 x2,
λ x4 . In x4 x3.