Post-partition, India retained its common law system. Much of contemporary Indian law shows substantial European and American influence. Legislation first introduced by the British is still in effect in modified form today. During the drafting of the Indian Constitution, laws from Ireland, the United States, Britain, and France were all synthesized to produce a refined set of Indian laws. Indian laws also adhere to the United Nations guidelines on human rights law and environmental law. Certain international trade laws, such as those on intellectual property, are also enforced in India.