Let x0 of type ι → ο be given.
Assume H0: ∃ x1 . x0 x1.
Apply H0 with
x0 (Eps_i x0).
Let x1 of type ι be given.
Assume H1: x0 x1.
Apply unknownprop_c3f0de4cb966012957ca752938aa96a32c594389e7aea45227d571c0506618ba with
x0,
x1.
The subproof is completed by applying H1.