Kernrechtsfrage
Whether the 1986 inheritance-contract clause on residual beneficiaries was contractual and binding, or merely testamentary and freely revocable.
Extrahierter Entscheid
The clause was contractual and therefore binding; it was not a freely revocable testamentary disposition.
Extrahierte Begründung
The lower court could infer a mutual intent to bind themselves also as to the residuary disposition; that factual interpretation was not reviewable on appeal.