Proofgold Proof

pf
Let x0 of type ι be given. Let x1 of type ι be given. Assume H0: ordinal x0. Assume H1: ordinal x1. Assume H2: SNo x0. Assume H3: SNo (add_SNo x0 x1). Apply add_SNo_ordinal_ordinal with x0, x1 leaving 2 subgoals. The subproof is completed by applying H0. The subproof is completed by applying H1. ■