In German patent law, the separation principle applies, according to which a patent claim is interpreted consistently in infringement and opposition, nullity and restriction proceedings. There is no mutual binding effect of decisions of the infringement or nullity courts, instead, each of the courts is responsible for determining the meaning of a patent claim, which is a legal question. For example, the grounds of a nullity decision on the maintenance of a patent with a restricted patent claim may serve as an interpretative aid for the infringement court. In principle, the currently valid version of a patent claim is relevant for its interpretation, and in the case of amendments in opposition or nullity or restriction proceedings, the amended version is therefore relevant. The subject matter of the patent claim is now determined by the wording of the restricted claim, as explained by the description and drawings in light of the grounds of the decision.