Condition or stipulation existing in law or contract. In law, it often refers to a condition without which the religious or legal act is rendered invalid. The shart is an element (rukn) that must be fulfilled in order for the legal act to be valid. For instance, a condition of valid prayer is purity, and a condition of a valid contract is consent. The term also refers to contractual stipulations either implied by law or expressly mandated by the contracting parties. Under classical and modern Islamic law, there are various options and warranties mandated by law into a contractual obligation. Furthermore, parties may expressly dictate conditions into the contract as long as such conditions are lawful. Classical and modern Islamic law vigorously debate which, if any, conditions may be dictated by the parties in a marriage contract. For instance, it is debated whether a woman may stipulate that her husband not move her away from her present residence or not take a second wife, otherwise the marriage is rendered invalid. Many Muslim countries permit women to insert such stipulations.