(2) The Tribunal may, where it is deemed necessary, request the production of evidence or the voluntary appearance of a witness or an expert witness at the hearings. However, the Tribunal may, at its discretion, proceed with the hearing even if evidence has not been submitted and/or neither a witness nor an expert witness has appeared within the designated time.
(3) In the event that the Tribunal is unable by itself to examine the evidence necessary for an arbitration award, the Tribunal may file an application with the competent court upon its own initiative or upon the request of any party.
(4) All evidence shall be submitted and examined in the presence of all the parties, and sole arbitrator or the majority of the arbitrators, except where any of the parties is absent without sufficient reason or has waived his right to be present.
(5) The Tribunal shall decide at his own discretion the relevancy and materiality of the evidence offered.

Article 43. Closing of Hearings

(1) The Tribunal shall, when it believes that all contentions and evidence of the parties have been put forth, declare the hearings closed.
(2) If it is required that a summary of statements be submitted, the hearings shall be deemed to be closed as of the final date set by the Tribunal for the submission of the aforementioned documents.