Rights and Obligations
When the performance of contractual obligations commences the parties must begin doing what they are meant to do as per the proper interpretation of the terms. During performance, if there is a change in circumstances or needs, they can either re-negotiate deliberately or just carry on and accept a change in practice. Either way the proper interpretation of formal rights and obligations is affected. If there is a dispute a court will interpret the contract principally by what the parties intended at first, and subject to any proven changes in their intentions.