International organizations — Immunity — Jurisdictional immunity — National of receiving State employed by international organization — Contract of employment — Termination — Claim for unlawful dismissal and reinstatement — Whether international organization entitled to jurisdictional immunity — Whether examination of legality of dismissal of employee would involve interference with public functions of international organization — Multinational Force and Observers (MFO) established under Egypt — Israel Peace Treaty, 1979 — Legal status of MFO — Whether entitled to jurisdictional immunity — MFO — Italy Headquarters Agreement, 1982 — Article 8 — Provision for immunity from jurisdiction of receiving State in absence of waiver — Whether express waiver required — Relevance of provision for settlement of employment disputes by arbitration — The law of Italy