Proofgold Proof

pf
Let x0 of type ι be given. Let x1 of type ι be given. Let x2 of type ι be given. Apply pack_e_e_1_eq with pack_e_e x0 x1 x2, x0, x1, x2. Let x3 of type ι → ι → ο be given. Assume H0: x3 (pack_e_e x0 x1 x2) (pack_e_e x0 x1 x2). The subproof is completed by applying H0. ■