Let x0 of type ι be given.
Let x1 of type ι be given.
Let x2 of type ι → ι be given.
Apply unknownprop_e852c379a4d149a0e7c3983079d37ed9544b96fff7464ba0659bb4d1fa26edaf with
x0,
x1,
x2,
x2 leaving 2 subgoals.
The subproof is completed by applying H0.
Let x3 of type ι be given.
The subproof is completed by applying Subq_ref with x2 x3.