Question juridique clé
Whether the cantonal court arbitrarily granted definitive legal opening despite the debtor's set-off defence
Solution extraite
The complaint failed; the debtor did not prove by sufficient documentary evidence that the enforced debt had been extinguished by set-off.
Motifs extraits
Under Art. 81(1) SchKG, extinction by set-off must be proved strictly by documents. The debtor's payment receipts and the 1996 judgment did not amount to a clear documentary title to a counterclaim or a non-reserved acknowledgment by the creditor. The 1996 judgment only dismissed the creditor's maintenance claim and did not decide on a counterclaim.