The action per the assessment of the nature usury of the interests due in base a a contract of leasing, with the consequent condemnation of the counterpart to the return of what unduly perceived a such a title, is susceptible of referring decision of the referees, in it is a an object Ritto Available, without the the deduced nullity of the contract place a base of the question, which concerns, instead, the merit of the claim, is a a to exclude the competence arbitration, being illogical to depend the operation of the convention of arbitration from the merit of the dispute.