An important thing to remember in terms of prior art and how to look at patents as prior art is that entire patent document is prior art. So sometimes even very savvy people get a little bit  confused and are looking at the claims of the patent and they think that if it’s not shown in the claims it doesn’t exist as prior art. But since prior art actually constitutes anything that’s known to mankind not just what’s in the claims of the patent it’s all the teachings of the patent, it’s everything in the drawings of the patent, anything that one of ordinary skill in the art would look at the patent document and understand constitutes prior art. And your invention has to be distinct over all of those things and not just over the claims of an issued patent.