are clearly erroneous.”) (citation omitted). Accordingly, we defer to the district court’s finding on unexpected results. BMS’s remaining arguments regarding unexpected results are that the district court committed legal error by (1) comparing enteeavir to another hepatitis B drug on the market instead of the closest prior art, 2'-CDG; and (2) inappropriately looked to what the inventor knew at the time of the invention — instead of one of ordinary skill in the art — to determine what was expected. BMS is correct on both counts. See Kao, 441 F.3d at 970 (explaining that when unexpected results are used as evidence of patent’s nonobviousness, results must be shown to be unexpected compared with closest prior art); Standard Oil Co. v. Am. Cyanamid Co., 774 F.2d 448, 454 (Fed.Cir.1985) (<HOLDING>) (emphasis omitted). However, both errors were
holding that obviousness is determined entirely with reference to a hypothetical person having ordinary skill in the art  and the actual inventors skill is irrelevant to the obviousness inquiry holding that summary judgment on grounds of obviousness did not require a supporting experts opinion holding of obviousness affirmed on the basis of the teachings of the prior art references in combination not on the basis of the contemporaneous invention holding that obviousness analysis may include recourse to logic judgment and common sense available to a person of ordinary skill that do not necessarily require explication in any reference or expert opinion holding that factual underpinnings of obviousness include whether reference provides motivation to combine its teachings with those of another reference