Art. 817 of the Italian Civil Code civ. Attributes to referees the power of decide in order to own competence, where the validity, the content or the width of the convention of arbitration or the regular constitution ne of the body referee are contested in the course of the procedure, specifying, per second paragraph, that such principle is applicable even in the case in i powers of the referees are contested in any one seat per any reason surviving in the course of the procedure. the character exclusive of the power recognized to referees from the aforementioned provision found then confirmation in dictation of art. 819-ter, co. 3, cod. proc. civ., to senses of which the slope of the procedure arbitration precludes the proposition of questions judicial with ad object the invalidity or ineffectiveness of the convention of arbitration.