Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι be given.
Apply unknownprop_91ac230cee6f6b845375b6f43e0a69c207c52d0119237822cf5bfa0b164f17fd with
x0,
x1,
x2,
prim1 x0 (prim2 x1 x2) ⟶ or (x0 = x1) (x0 = x2).
The subproof is completed by applying H0.