An arbitration clause contained in a contract specifically negotiated between the parties is not subject to the requirement of double signature under art. 1341 cod. civ., since that provision applies exclusively to general conditions of contract unilaterally drafted by one of the parties.
Where the objection of incompetence of the ordinary court in favour of the arbitrators has been upheld, duly raised in opposition proceedings against a payment order, the opposed order must be set aside and declared void.