Kernrechtsfrage
Whether a valid lease for the premises existed despite the signature and form clause arguments.
Extrahierter Entscheid
A valid lease existed; any contractual form reservation could be waived by subsequent conduct, and the defendants were estopped from denying the contract after years of performance.
Extrahierte Begründung
The parties exercised the contract for about four and a half years. A form reservation may be waived or modified informally, including by conclusive conduct. The defendants' denial was inconsistent with their prior behavior and therefore abusive.