They don't do that. It is all written in the patent already. Court decides if you're out. Wastes time and money. You may not even understand the patent text. For the prior art I have a bold solution: all published material should be freely available, legally or not. Soon one finds punch of volunteers who are willing to browse all that material for finding prior art. That won't happen if they would have to spend $$$$$$ in purchasing the materials first. Patent offices are leaving the prior art browsing for us -- if you have seen how infrequently they refer outside the patent database. Somebody gotta loose and I prefer the publishers rather than us. Juhana -- http://music.columbia.edu/mailman/listinfo/linux-graphics-dev for developers of open source graphics software