 Three decades later, the Supreme Court most recently revisited the obviousness standard.In "KSR International Co. v. Teleflex Inc.", the Court rejected the Federal Circuit's approach to determining obviousness as insufficiently faithful to the "Hotchkiss" standard as explained in "Graham v. Deere".The Federal Circuit had been using a "rigid" test known as "the 'teaching, suggestion, or motivation' test (TSM test), under which a patent claim is only proved obvious if 'some motivation or suggestion to combine the prior art teachings' can be found in the prior art, the nature of the problem, or the knowledge of a person having ordinary skill in the art."