Kernrechtsfrage
Whether the Federal Court could review the cantonal court's application of foreign law only under the arbitrariness standard in this provisional-measures case.
Extrahierter Entscheid
The court could only review constitutional violations; the cantonal court was entitled to determine foreign law ex officio and rely on the standard commentaries.
Extrahierte Begründung
Because the challenged order was a provisional measure, only constitutional rights could be invoked. Under Art. 16 IPRG the court determines foreign law ex officio; no arbitrariness arose from relying on accepted German commentaries rather than the appellant's unsupported contrary view.