Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι → ι be given.
Let x3 of type ι be given.
Apply unknownprop_982af5658c6b0e50ce5ee412e8d18f10049cbf64990014797a7943421c77d50c with
5f184.. x0 x1 x2 x3,
x0,
x1,
x2,
x3.
Let x4 of type ι → ι → ο be given.
The subproof is completed by applying H0.