The concept that the claims defining an invention in a patent application must not be a predictable improvement on what has been done or published before the priority date
The concept that the claims defining an invention in a patent application must involve an inventive step if, when compared with what is already known (i e prior art), it would not be obvious to someone skilled in the art
An invention defined in a patent claim can be unpatentable even if it passes the novelty test The U S patent statute provides that the claim is unpatentable if the claimed subject matter would have been "obvious" to a person of ordinary skill in view of what was already known See Nonobviousness in U S Patent Law A similar rule applies in most foreign countries