Enforcement of an extrajudicial enforcement instrument linked to a contract containing an arbitration clause. Special appeal filed on the allegation of encroachment upon the jurisdiction of the arbitral tribunal by the judiciary. The state appellate court limited itself to deciding that the enforcement of the extrajudicial enforcement instrument must proceed. Given that no deliberation on the validity of a contractual clause was made by the judiciary, no violation of Article 8, sole paragraph, of the Brazilian Arbitration Act was found to have occurred, with all matters of cognition relating to the contract and the validity of the instruments subject to enforcement remaining reserved to the arbitrators: