Contract – Validity. Even on the assumption that all the relevant contractual obligations were unlawful and unenforceable as a matter of United Arab Emirates law, the claimant's arguments, based on interpretation, mistake and English public policy, challenging the validity and enforceability of the first defendant trustee's rights under a purchase undertaking to oblige the claimant to pay an exercise price, were unfounded. Accordingly, the Commercial Court declared that the purchase undertaking was valid and enforceable in accordance with its terms.