Private instrument for the purchase and sale of real property, corporate quotas, and various installations with an arbitration clause. Amendment to the articles of association with a forum selection clause. Claim for rescission of the real property purchase and sale contracts filed in arbitration proceedings. Respondent party that does not sign the agreement to arbitrate and files a counterclaim seeking rescission of the corporate quota purchase and sale contract, which is not accepted by the arbitral tribunal on account of the forum selection clause in the amendment to the articles of association. Filing of a lawsuit before the judiciary seeking suspension of the arbitration proceedings, which is denied. Recognition of the arbitrators' jurisdiction to analyze their own jurisdiction over the corporate quota purchase and sale contract, given that the decision on their lack of jurisdiction was incidental in nature and would not yet constitute res judicata: