Questão jurídica principal
Whether the federal appeal was admissible under federal law, given the legal nature of the reimbursement promise tied to the land sale.
Decisão extraída
The promise was an accessory modification of the land-sale contract and therefore governed by cantonal law; the federal appeal was inadmissible.
Fundamentação extraída
The obligation was concluded in close connection with the sale, expressly as an adjunct to the same-day contract, and in substance operated as a conditional price reduction. As it stood and fell with the land sale, it shared the same legal regime as that contract. Since the sale was an immovable-property sale governed by cantonal law, no federal-law issue justified appellate jurisdiction.