Proofgold Proof

pf
Let x0 of type ι be given. Let x1 of type ι be given. Assume H0: x0 = x1 ⟶ False. Assume H1: x1 = x0. Apply H0. Let x2 of type ι → ι → ο be given. The subproof is completed by applying H1 with λ x3 x4 . x2 x4 x3. ■