Law firm. Exclusion of a partner. Arbitration clause for the determination of the buyout amount. Arbitration proceedings closed before the definitive determination due to failure to examine all evidence and due to having "been disregarded by the interested parties". Absence of "reiteration of the issue of the arbitration clause on appeal, rendering it precluded and preventing the referral of the proceedings to the arbitral tribunal". Elements "of conviction [from the arbitration proceedings] presented up to that point, at most, may serve as a parameter for the enforcement phase of these proceedings, at which time a new expert examination shall establish the amounts to be paid":