Let x0 of type ι be given.
Let x1 of type ι → ι → ι be given.
Let x2 of type ι → ι → ι be given.
Let x3 of type ι → ι → ο be given.
Let x4 of type ι → ι → ο be given.
Assume H0:
∀ x5 . prim1 x5 x0 ⟶ ∀ x6 . prim1 x6 x0 ⟶ x1 x5 x6 = x2 x5 x6.
Assume H1:
∀ x5 . prim1 x5 x0 ⟶ ∀ x6 . prim1 x6 x0 ⟶ iff (x3 x5 x6) (x4 x5 x6).
Apply unknownprop_dbb26cd650ab4f49eb7a56474ebdc3b4a46f79fd66ae7129c609d055a8e1a150 with
x0,
x1,
x2.
The subproof is completed by applying H0.