The principle of "implied repeal" is that if a portion of a law
supersedes a portion of another law, the older law is automatically repeal
ed and replaced by the new law.
In most parts of the world, the constitution and basic laws are not subject to implied repeal (i.e. they stand until they are specifically repealed), but all other laws are. A notable exception is the European Union, where the founding treaties and community regulations are also immune to implied repeal (see Costa v. ENEL (Case 6/64)).