Mentor Graphics Corporation declined to comment yesterday on a German court’s ruling in favor of Quickturn Design Systems Inc, ordering Mentor to refrain from offering or marketing emulation systems in that country on grounds of patent infringement. A court in Dusseldorf ruled against Mentor at the end of April, not only instructing Mentor to cease selling its software in Germany but awarding San Jose, California-based Quickturn damages. A spokesperson for Quickturn said this was the sixth consecutive victory for the company against mentor in this patent dispute, which has been running for some two years. The previous five rulings were all in US courts. Mentor, on the other hand, declined to comment. Sources close to he company said it is seeking to adopt a conciliatory position.