Let x0 of type ι be given.
Let x1 of type ι be given.
Apply unknownprop_b51c738b3a14385af55eef02a445728dc056a37996fdc42e5ede8e064af23c97 with
e4431.. x0,
e4431.. x1,
λ x2 . prim1 x2 x0,
λ x2 . prim1 x2 x1 leaving 3 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.
The subproof is completed by applying H2.