Article 356 — Grounds for application

No application under Art. 355 shall be made except where : (a) tltll arbitrator decided'matters not referred to him or made his award pursuant to a submission wbich was invaM or had lapsed; (b) the reference being to two or more arbitrators, they did Dot act together; or . (C) tne arbitrator delegated any part of his authority. whether to a stranger, to one of the parties or to a co-arbitrator.