Let x0 of type ι be given.
Apply CSNo_I with
minus_SNo (CSNo_Re x0),
minus_SNo (CSNo_Im x0) leaving 2 subgoals.
Apply SNo_minus_SNo with
CSNo_Re x0.
Apply CSNo_ReR with
x0.
The subproof is completed by applying H0.
Apply SNo_minus_SNo with
CSNo_Im x0.
Apply CSNo_ImR with
x0.
The subproof is completed by applying H0.