We review the Board's obviousness determination de novo. See In re Brandt, 886 F.3d 1171, 1175 (Fed. Cir. 2018). We review underlying factual findings-including what a reference teaches and whether there is a motivation to combine-for substantial evidence.

"[T]he concept of prima facie obviousness establishes the framework for the obviousness determination and the burdens the parties face" during patent examination. ACCO Brands Corp. v. Fellowes, Inc., 813 F.3d 1361, 1365 (Fed. Cir. 2016); see also In re Brandt, 886 F.3d 1171, 1176 (Fed. Cir. 2018) (describing the prima facie framework as well). "Under this framework, the patent examiner must first set forth a prima facie case, supported by evidence, showing why the claims at issue would have been obvious in light of the prior art."

Furthermore, the Federal Circuit-in published, binding opinions-has held that the Range Framework also applies in cases involving ranges that, while not overlapping, “are so close that prima facie one skilled in the art would have expected them to have the same properties.” In re Brandt, 886 F.3d 1171, 1178 (Fed. Cir. 2018) (collecting cases) (quoting Titanium Metals Corp. v. Banner, 778 F.2d 775, 783 (Fed. Cir. 1985)).

Claim construction and obviousness are both questions of law that depend on underlying findings of fact, which are reviewed for substantial evidence. Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 325-28 (2015); In re Brandt, 886 F.3d 1171, 1175 (Fed. Cir. 2018).

Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 325-28 (2015); In re Brandt, 886 F.3d 1171, 1175 (Fed. Cir. 2018).

Claim construction and obviousness are questions of law that depend on underlying findings of fact, which are reviewed for substantial evidence. Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 325-28 (2015); In re Brandt, 886 F.3d 1171, 1175 (Fed. Cir. 2018). "Indefiniteness is a question of law that we review de novo, subject to a determination of underlying facts, which we review for substantial evidence."

But overlap is not strictly necessary for a conclusion of obviousness: "obviousness exists when the claimed range and the prior art range do not overlap but are close enough such that one skilled in the art would have expected them to have the same properties." In re Peterson , 315 F.3d 1325, 1329 (Fed. Cir. 2003) ; accord In re Brandt , 886 F.3d 1171, 1177 (Fed. Cir. 2018) ; Valeant Pharms. Int'l, Inc. v. Mylan Pharms. Inc. , 955 F.3d 25, 32 (Fed. Cir. 2020).

In this circumstance, "the burden shifts to the patentee to provide evidence" to rebut the examiner's prima facie case—here, specifically, to show that the claimed inhibition of reduction would not result. See In re Brandt, 886 F.3d 1171, 1176 (Fed. Cir. 2018); ACCOBrands Corp. v. Fellowes, Inc., 813 F.3d 1361, 1365-66 (Fed. Cir. 2016); In re Best, 562 F.2d 1252, 1255 (CCPA 1977). Mr. Rajagopalan has not undermined the Board's determination that he did not rebut the prima facie case.

Mayo has not asserted any authority contrary to our understanding. See, e.g. , In re Brandt , 886 F.3d 1171, 1175–76 (Fed. Cir. 2018) (examination involves a process of initial and final rejections and "if the applicant timely requests continued examination, [that] process is repeated").At the heart of Mayo's appeal is the misapprehension that the examiner could not have issued a rejection that "had nothing to do with any issue raised in the [RCE]," Mayo Br. 24, or, at the very least, that such time should not be deducted from B Delay.

With proper numerical data or standards, a party may claim a physical element associated with a patent is nominal or negligible. See In re Brandt, 886 F.3d 1171, 1177 (Fed. Cir. 2018) (finding the claimed density range of "less than 6 pounds per cubic feet" and the prior art range of "between 6lbs/ft3 and 25lbs/ft3" are so mathematically close that the range difference is "virtually negligible"); Noven Pharms., Inc. v. Mylan Techs. Inc., No. 17-1777, 2018 U.S. Dist. LEXIS 144722, at *5 n.4 (D. Del. Aug. 20, 2018) (calling a flux rate of 0.01 mg/cm2/day or less "nominal"); Jiffy Enters., Inc. v. Sears, Roebuck & Co., 306 F.2d 240, 243 (3d Cir. 1962) (confirming, beyond any reasonable doubt, the differences in weight, mobility of the hook, or thickness between two hangers are not readily perceptible to the senses and therefore "negligible"); Glaxo Wellcome, Inc. v. Genentech, Inc., 136 F. Supp. 2d 316, 336 (D. Del. 2001) (calling a degradation rate at less than 1% of a designated peak value "negligible"). Defendants provide none of these reasonings.