Kernrechtsfrage
Whether the separation agreement of 21 December 2009 was invalid due to fundamental error.
Extrahierter Entscheid
No invalidity was shown; the alleged mistaken assumption about a housing-cost contribution was not established.
Extrahierte Begründung
The court held that the wife had not proven a divergence between reality and her understanding of it. On the findings, she did not pay the housing contribution, so the factual premise of the alleged error failed; evidentiary proceedings were unnecessary.