If the subject-matter of a granted German patent is an invention for which a European patent to the same inventor or its successor in law has been granted (which has the same priority and is valid in Germany) then the German patent becomes ineffective to the extent to which it protects the same invention as the European patent. This happens (1) at the end of the opposition period of the European patent, provided no opposition has been filed, or (2) at the end of European opposition proceedings, provided the European patent has been (at least partially) maintained, or (3) when the German patent is granted after (1) or (2).