(which may also give you some additional ideas on appropriate wording)

A presumption of validity
(...) This philosophy of considering a patent to be a legal right with a presumption of validity, rather than something which had to be proven again from square one, found its expression in the principle of separation, which is still used today in German courts. According to this principle, a special patent court re-examines the validity of a patent, while a separate infringement court deals with the issue of infringement and presumes the patent to be valid.
http://www.iam-magazine.com/issues/Article.ashx?g=7e20eb5e-d...

It is unique not only in Europe but also in the entire world that the judge dealing with an infringement case is bound by the facts of patent grant and is not authorized to question the legal effectiveness of the patent. The judicial examination of legally granted patents is not the task of the infringement court but of the German Federal Patent Court (in first instance) and the German Federal Supreme Court (in the second instance) in a separate revocation procedure.

The grant of a patent is an administrative act conferring a benefit, that is, substantiating an exclusive right and a right of use. For this solely (in the case of lawful grant) the German Federal Patent Court and the Federal Supreme Court have exclusive examining competence. So long as a patent is formally effective, the infringement court is bound by it (effect of the fact) and must accept the patent as it was granted.
http://books.google.co.uk/books?id=OJsJUz8QHkYC&pg=PA405&lpg...