Proofgold Proof

pf
Let x0 of type ι be given. Let x1 of type ι be given. Let x2 of type ι be given. Assume H0: Subq x0 x1. Assume H1: Subq x1 x2. Let x3 of type ι be given. Assume H2: prim1 x3 x0. Apply H1 with x3. Apply H0 with x3. The subproof is completed by applying H2. ■