Proofgold Proof

pf
Let x0 of type ι be given. Assume H0: x0 ∈ complex. Apply CSNo_pair_0 with x0, λ x1 x2 . x1 ∈ quaternion. Apply quaternion_I with x0, 0 leaving 2 subgoals. The subproof is completed by applying H0. The subproof is completed by applying complex_0. ■