The Federal Circuit stated in an en banc decision in Cybor Corp. v. FAS Technologies, Inc. that the construction of patent claims is a purely legal issue, and is therefore subject to de novo review on appeal. The Cybor decision reaffirmed the position of the majority of the Federal Circuit which had been announced in its en banc Markman decision, and proclaimed that the de novo standard of review is supported by the Supreme Court\u27s Markman decision, a Seventh Amendment opinion. However, Cybor included strong opposition to a de novo standard of review from some of the judges of the Federal Circuit. Moreover, in subsequent cases, the consistent citation of Cybor in support of the application of a de novo standard of review of claim const...