In almost all patent systems an invention must not be obvious to someone of ordinary skill in the art. In U.S. law novelty is a different issue from obviousness—an invention is only non-novel if it was wholly and essentially identically described (i.e., all claim limitations met) in a single publication from the prior art, whereas an invention is obvious under 35 U.S.C. §103 if the invention would have been obvious to someone of ordinary skill in the art, especially someone who had knowledge of the prior art, even if that person needs to combine items of prior art. In other words, novelty asks if someone has actually made it before, obviousness asks if a reasonably skilled and educated person could have made it before had they considered the problem and the existing art. In Europe, obviousness is usually referred to as “lack of inventive step” echoing the language of Article 56 of the European Patent Convention.