Questione giuridica chiave
Whether the contribution claim of CHF 13,198.20 could still be enforced despite the earlier withdrawal decision
Decisione estratta
The contribution debt had already been definitively confirmed in earlier proceedings and could no longer be challenged here.
Motivazione estratta
The same argument had been finally decided in the prior case; the cantonal judgment of 22 December 2016 was final, and the Federal Supreme Court had not entered into the subsequent complaint.