Efficacy of the arbitration clause. Contractual clause that initially states that disputes between the parties "are submitted exclusively to the courts with jurisdiction over this contract." Subsequent clause of the same contract stating that "any dispute arising out of or relating to this contract (…) shall be resolved by arbitration." Considering the jurisdictional nature of arbitration, the interpretation is that arbitration was validly chosen. The expression "may" (may call) inserted in a subsequent paragraph of the same clause refers only to the manner of initiating the arbitration proceedings and does not taint the prior provision establishing the mandatory use of arbitration: