(a) The arbitration tribunal shall decide the dispute according to the rules of law designated by the parties as applicable to the substance of the dispute.
(b) Unless otherwise expressed, a designation by the parties of the law or legal system of a given state refers to the substantive law of that state and not to conflict-of-laws rules.

(c) If the parties do not make a designation under Subsection (a), the arbitration tribunal shall apply the law determined by the conflict-of-laws rules that the tribunal considers applicable.
(d) The arbitration tribunal shall decide ex aequo et bono or as amiable compositeur if each party has expressly authorized it to do so.
(e) In each case, the arbitration tribunal shall:
(1) decide in accordance with the terms of the contract; and
(2) take into account the usages of the trade applicable to the transaction.