Absence of jurisdiction of the Brazilian judiciary to hear and adjudicate a lawsuit to annul a foreign arbitration award. Allegation of a defect of consent in the arbitration clause. "Even if the claimants had entered into the arbitration agreement by mistake, as they allege, the defect was cured from the moment they themselves petitioned for the constitution of the arbitral tribunal in order to resolve their disputes. The situation clearly constitutes tacit confirmation of the legal transaction":