Arbitration — Jurisdiction — Extent of mandate — Power to interpret mandate — Competence de la compétence — Finality and review of arbitral awards — Panel of experts — Arbitration tribunal with power to review decision of experts — Standard of review — Test of whether experts exceeded mandate — Whether interpretation of mandate reasonable — Whether implementation of mandate reasonable — Failure to state reasons — Whether amounting to excess — Procedural irregularities — Whether power to annul decision in part implicit in mandate of arbitration tribunal — Arbitration Agreement between the Government of Sudan and the Sudan People’s Liberation Movement/Army

Arbitration — Evidence — Value of different types of evidence — Cartographic evidence — Requirement that findings be based on evidence and properly reasoned

Territory — Boundaries — Internal administrative boundary — Relevance of international law principles respecting boundaries between States — Territory inhabited by tribal and nomadic peoples — Transfer of the area of certain chiefdoms from one province to another in 1905 — Extent of territory so transferred — Whether to be approached on tribal or territorial basis — Grazing rights of nomads — Sudan — Abyei area

Treaties — Interpretation — Vienna Convention on the Law of Treaties, 1969 — Application of principles of treaty interpretation in international law to agreements between Government of Sudan and Sudan People’s Liberation Movement/Army