Unless an express agreement on such matters is reached in the contract itself, countries will have rules to determine the law applicable to the contract and the jurisdiction for disputes. For example, European Member States apply Article 4 of the Rome I Regulation to decide on the law governing the Treaty and the Brussels I Regulation to decide on jurisdiction. If the terms of the contract are uncertain or incomplete, the parties may not have reached an agreement in the eyes of the law.  An agreement does not constitute a contract, and failure to agree on key issues that may include elements such as price or safety may result in the failure of the entire contract. However, a court will attempt to make commercial contracts possible by interpreting an appropriate interpretation of the contract.