Let x0 of type ι be given.
Let x1 of type ι → ι be given.
Let x2 of type ι be given.
Let x3 of type ι be given.
Assume H1:
prim1 x3 (x1 x2).
Apply UnionI with
94f9e.. x0 x1,
x3,
x1 x2 leaving 2 subgoals.
The subproof is completed by applying H1.
Apply unknownprop_4785a7374559bd7d78314ce01f76cab97234c9b29cfa5b01c939c64f8ccf18e4 with
x0,
x1,
x2.
The subproof is completed by applying H0.