Wisconsin Alumni Research Foundation v. Apple Inc.

• Court: Court of Appeals for the Federal Circuit
• Decided: August 28, 2024
• Docket: 22-1884
• Status: Published

Opinion

Case: 22-1884 Document: 54 Page: 1 Filed: 08/28/2024

United States Court of Appeals for the Federal Circuit ______________________

WISCONSIN ALUMNI RESEARCH FOUNDATION, Plaintiff-Appellant

v.

APPLE INC., Defendant-Appellee ______________________

2022-1884, 2022-1886 ______________________

Appeals from the United States District Court for the Western District of Wisconsin in Nos. 3:14-cv-00062-wmc, 3:15-cv-00621-wmc, Judge William M. Conley. ______________________

Decided: August 28, 2024 ______________________

MORGAN CHU, Irell & Manella LLP, Los Angeles, CA, argued for plaintiff-appellant. Also represented by ALAN J. HEINRICH, AMY E. PROCTOR.

WILLIAM F. LEE, Wilmer Cutler Pickering Hale and Dorr LLP, Boston, MA, argued for defendant-appellee. Also represented by ANDREW J. DANFORD, LAUREN B. FLETCHER; STEVEN JARED HORN, Washington, DC. ______________________

Before PROST, TARANTO, and CHEN, Circuit Judges. Case: 22-1884 Document: 54 Page: 2 Filed: 08/28/2024

PROST, Circuit Judge. Wisconsin Alumni Research Foundation (“WARF”) ap- peals two final judgments of the U.S. District Court for the Western District of Wisconsin in Case Nos. 14-cv-062 (“WARF I”) and 15-cv-621 (“WARF II”). Wis. Alumni Rsch. Found. v. Apple, Inc., No. 14-cv-062, No. 15-cv-621, 2022 WL 2080153 (W.D. Wis. May 10, 2022), J.A. 1‒13. With respect to WARF I, the district court denied WARF’s re- quest to pursue an abandoned doctrine-of-equivalents the- ory and entered judgment in favor of Apple Inc. (“Apple”) of noninfringement of U.S. Patent No. 5,781,752 (“the ’752 patent”). The district court also entered a final judgment in favor of Apple in WARF II, which accused similar, next- generation Apple products of infringing the same ’752 pa- tent, finding that action barred by WARF I. For the rea- sons below, we affirm the district court’s judgment in both WARF I and WARF II. BACKGROUND This case began more than ten years ago and involves a patent that has long since expired. The lengthy litigation history is scattered with strategic decisions that gave rise to the current appeal. We therefore begin with a mostly chronological retelling of the major events that have led to the matter before us. In short, before us are the appeals from two district court cases with the same parties, the same patent, and multiple generations of the accused product. WARF ac- cused Apple’s A7 and A8 processors of infringing the ’752 patent in WARF I. In WARF II, separately filed on the eve of trial in WARF I, WARF accused Apple’s A9 and A10 pro- cessors of infringing the ’752 patent. In WARF I, the jury found Apple’s A7 and A8 literally infringed the ’752 patent. Apple appealed, arguing no reasonable jury could find Ap- ple literally infringed under the plain and ordinary mean- ing of “particular” as used in the asserted claims. We agreed and reversed the prior judgment. On remand, Case: 22-1884 Document: 54 Page: 3 Filed: 08/28/2024

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WARF attempted to reassert infringement against A7 and A8 under the doctrine of equivalents. The district court denied that request based on WARF’s prior affirmative abandonment of that theory. WARF II was stayed during the pendency of the previous appeal because the claim con- struction dispute was also relevant to the A9 and A10 pro- cessors accused in WARF II. Following the remand in WARF I, WARF attempted to continue WARF II against A9 and A10 under the doctrine of equivalents. But the district court found that WARF I precluded WARF from proceeding in WARF II. The context of these events is explained in more detail below. I The ’752 patent was filed on December 26, 1996, and issued on July 14, 1998. The patent is titled “Table Based Data Speculation Circuit for Parallel Processing Com- puter” and is directed to “[a] predictor circuit [that] permits advanced execution of instructions.” ’752 patent Abstract. “In an electronic computer with a single processing unit . . . . [t]he order in which the instructions are executed is determined by the value of a program counter within the processing unit.” Id. at col. 1 ll. 22‒32. “One method of increasing the speed of electronic computers involves using multiple processing and/or functional units to execute mul- tiple instructions at the same time or in an ‘execution or- der’ differing from the program order.” Id. at col. 1 ll. 50‒53. “An instruction level parallel (‘ILP processing unit’) is one where individual instructions of a single program are separated to be run on different processing units . . . .” Id. at col. 1 ll. 55‒57. But “as the ILP processing unit prepares to execute an instruction, it cannot always determine if the instruction will in fact be dependent on earlier instructions that have not yet completed their execution.” Id. at col. 2 ll. 18‒22. In some circumstances, “the ILP processing unit is forced to assume dependencies exist,” while in other cir- cumstances, “an ambiguous dependency is resolved as no dependency.” Id. at col. 2 ll. 24‒27. Case: 22-1884 Document: 54 Page: 4 Filed: 08/28/2024

“[S]ome ILP processors may provide for ‘speculation’, that is, execution of an instruction that has ambiguous de- pendency as if it had no dependency at all.” Id. at col. 2 ll. 28‒30. Yet “in the course of execution of instructions, [an ILP processing unit] may execute some dependent in- structions before the instructions on which they are de- pendent,” referred to as a mis-speculation. Id. at col. 2 ll. 45‒47; see also Appellant’s Br. 6. “A cumbersome or in- accurate speculation system may hurt overall system per- formance . . . .” ’752 patent col. 3 ll. 18‒19; see also Appellant’s Br. 6 (“[A] ‘mis-speculation’ . . . caus[es] an er- ror and harm[s] performance.”). To overcome these prob- lems, the ’752 patent claims a processor with a “data speculation circuit for detecting data dependence between instructions and detecting a mis-speculation.” ’752 patent claims 1, 9. II A On January 31, 2014, WARF filed a complaint against Apple, thus beginning WARF I. The complaint accused the Load-Store Dependency Predictor (“LSD Predictor”) in Ap- ple’s A7 processor of infringing the ’752 patent. See J.A. 1001‒06. WARF later served its supplemental in- fringement contentions, accusing Apple’s A7, A8, A9, and A10 processors of infringing claims 1‒3, 5‒6, and 9 of the ’752 patent. 1 In October 2014, WARF moved to compel dis- covery related to A9 and A10. Apple objected to the pro- duction of discovery on A9 and A10 because they were still under development and subject to design changes. Apple submitted a declaration with its opposition to WARF’s

1 For simplicity, we refer to the A8 and A8X proces- sors collectively as A8; the A9 and A9X processors collec- tively as A9; and the A10 and A10X processors collectively as A10. Case: 22-1884 Document: 54 Page: 5 Filed: 08/28/2024

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motion, stating: “A9 is still in development. . . . [M]ajor changes will occur at A9’s stage of design. One change be- ing considered for A9 involves the LSD Predictor”; and “sig- nificant design changes are being considered for at least one model of the A10 design, including at least one signifi- cant change involving the LSD Predictor.” Appellant’s Br. 9 (cleaned up). Based at least in part on (1) the release dates for A9 and A10, which would not occur until the fall of 2015 for A9 (when trial was already scheduled) and 2016 for A10, (2) the need for experts to review materials prior to the deadline for expert reports in January 2015, and (3) the deadline for summary-judgment motions in March 2015, the district court concluded “[w]e can’t just keep add- ing additional products that are still being worked on.” J.A. 15129. The court reasoned that “the fairest line to draw right now is with all of the currently released prod- ucts,” J.A. 15129, and it denied WARF’s motion to compel discovery related to A9 and A10. J.A. 15135. In September 2015, less than two weeks before the scheduled WARF I trial, WARF filed a second lawsuit, WARF II, accusing the LSD Predictor in A9 of infringing the ’752 patent. J.A. 1008‒14. In March 2016, WARF moved to amend its complaint, adding A10 to the list of ac- cused products. J.A. 8006‒14. B WARF originally pursued both a literal and doctrine- of-equivalents theory of infringement in WARF I. Wis. Alumni Rsch. Found., 2022 WL 2080153, at *1. About a month before the WARF I trial, WARF filed a motion in limine to exclude evidence and argument regard- ing Apple’s U.S. Patent Application No. 13/464,647 (“the ’647 application”), which later issued as U.S. Patent No. 9,128,725. Apple opposed the motion because it in- tended to use the ’647 application to rebut WARF’s doc- trine-of-equivalents theory and WARF’s arguments that the ’752 patent is not invalid. J.A. 6810‒16. During Case: 22-1884 Document: 54 Page: 6 Filed: 08/28/2024

briefing, however, WARF “agreed to ‘drop doctrine of equiv- alen[ts] and make no doctrine of equivalents arguments whatsoever at trial’” in exchange for Apple’s agreement not to offer the ’647 application at trial. J.A. 15290. The court thereafter denied WARF’s motion in limine but ordered, based on the parties’ agreement, that “neither side may in- troduce evidence or argument regarding the ’647 applica- tion . . . during the liability phase of trial.” J.A. 15294. In October 2015, the jury returned a verdict of literal infringement in WARF I. III A During the WARF I trial, Apple moved for judgment as a matter of law under Federal Rule of Civil Procedure 50(a) on WARF’s abandoned noninfringement claims. Shortly after trial, the district court denied the motion but noted that “any attempt by WARF to resurrect abandoned claims would be futile in light of preclusion rules.” J.A. 15322. After the WARF I trial, Apple moved for renewed judg- ment as a matter of law under Federal Rule of Civil Proce- dure 50(b) on literal infringement, arguing that no reasonable jury could find that Apple’s accused products literally infringe because, among other reasons, Apple’s LSD Predictor did not “produce a prediction associated with the particular [load] instruction.” ’752 patent claim 1 (emphasis added); see also J.A. 15333‒34. Instead, “Apple explained that the plain and ordinary meaning of ‘particu- lar’ meant that the claimed ‘prediction’ must be associated with a single load instruction (i.e., one and only one load instruction), rather than with a group of load instructions.” Wis. Alumni Rsch. Found. v. Apple Inc., 905 F.3d 1341, 1347 (Fed. Cir. 2018) (“2018 Decision”) (emphases in origi- nal). WARF’s infringement theory, Apple argued, rendered the term “particular” meaningless. Case: 22-1884 Document: 54 Page: 7 Filed: 08/28/2024

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Apple raised this argument as a noninfringement de- fense as early as March 2015 in its expert report. But the dispute over the meaning of “particular” was resurrected during trial when WARF moved to exclude Apple’s nonin- fringement defense as inconsistent with the plain and or- dinary meaning of “particular.” The district court denied WARF’s motion “because Apple’s non-infringement argu- ment . . . was consistent with the plain meaning of ‘partic- ular’ as contemplating association with a single load instruction.” Wis. Alumni Rsch. Found., 2022 WL 2080153, at *2. Apple then asked the court to enter a jury instruction regarding the meaning of “particular,” but the court denied this request because the parties had failed to seek a claim construction for the term. Id. Ultimately, the district court denied Apple’s renewed motion for judgment as a matter of law and entered a final judgment of infringement against Apple. J.A. 15328; J.A. 15372‒73. Apple appealed, and we reversed, explain- ing that “the plain meaning of ‘particular,’ as understood by a person of ordinary skill in the art after reading the ’752 patent, requires the prediction to be associated with a single load instruction. A prediction that is associated with more than one load instruction does not meet this limita- tion.” 2018 Decision, 905 F.3d at 1348 (emphasis in origi- nal). Then, we determined that even “drawing all reasonable inferences in favor of WARF, there is insuffi- cient evidence to support the jury’s finding that Apple’s products literally satisfy the ‘particular’ limitation.” 2 Id. at 1350.

2 We also noted at that time that “WARF abandoned its theory of infringement under the doctrine of equivalents before trial, and has proceeded only on a theory of literal infringement.” 2018 Decision, 905 F.3d at 1347 n.5. Case: 22-1884 Document: 54 Page: 8 Filed: 08/28/2024

B WARF also filed post-trial motions after the WARF I trial in 2015—for example, regarding the similarity be- tween the A7 and A8 processors accused in WARF I and the A9 processor accused in WARF II. 3 In a motion for equita- ble relief, WARF argued that A9 uses “the same infringing LSD Predictor design” as A7 and A8. Appellee’s Br. 8; J.A. 7005‒06, 7008. In response, Apple confirmed that the “LSD Predictor in its recently released [A9] products is not more than colorably different from the LSD Predictor in the [A7 and A8] products addressed at trial.” J.A. 7127. And Apple did not oppose WARF’s request to include A9 in the calculation of damages from WARF I. WARF also filed a motion for an accounting, supplemental damages, and in- terest, the briefing of which again confirmed the similari- ties between A7, A8, and A9. For example, in response to WARF’s motion, Apple agreed that “any award of supple- mental damages should include not only Apple products containing the [A7 and A8 processors] but also Apple prod- ucts containing the [A9 processors]” because “Apple does not dispute that the LSD Predictor contained in the [A9] products is not more than colorably different, with respect to the asserted claims of the ’752 patent, from the LSD Pre- dictor in the [A7 and A8] products that were addressed at trial.” J.A. 7045‒46. Apple explained that the inclusion of A9 in the damages award would “eliminate[] the need to pursue [WARF II] further.” J.A. 7046. In June 2017, the district court, in response to WARF’s motion for an accounting and supplemental damages, or- dered the parties to brief their positions on consolidating WARF II with WARF I and awarding damages for

3 A10 was not yet asserted as an accused product in WARF II at the time of this post-trial briefing in 2015. Case: 22-1884 Document: 54 Page: 9 Filed: 08/28/2024

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infringement of A9 and A10. 4 J.A. 15362‒63. WARF stated that, although “[t]he parties appear to agree with the [c]ourt’s proposal in substance,” it believed that “the most efficient path forward would be to enter final judg- ment regarding the [A7 and A8] chips now and to defer, until after Apple’s appeal is complete, the more extensive discovery that will be required for the [A9 and A10] chips.” 5 J.A. 7129. WARF also stated that “Apple represented that it would not dispute that the [A9] and A10 chips are not more than colorably different from the [A7 and A8] chips with respect to the accused feature,” and “[t]he parties are now working together to formulate a stipulation to this ef- fect.” J.A. 7129–30; see also Appellant’s Reply Br. 29‒30; Appellee’s Br. 8. WARF explained that “[s]hould WARF prevail on appeal, then the task of calculating the numbers of infringing units of [the A9 and A10] processors can re- sume in [WARF II] once the stay is lifted. Conversely, should Apple prevail on appeal, there may be no need for such calculations.” J.A. 7130; see also Appellee’s Br. 19, 57–58; Appellant’s Reply Br. 29. Apple, in response, did not oppose WARF’s proposal to keep the two cases uncon- solidated but again confirmed that the damages award for A9 and A10 should be awarded at the same rates as A7 and A8 because the LSD Predictor in each generation of chips was “not more than colorably different.” J.A. 7148–50.

4 By this time, WARF had amended its complaint in WARF II to add A10 as an accused product. 5 The only additional discovery that WARF asserted may be necessary for A9 and A10 was related to damages— e.g., information on the number of unit sales, the effect of the ’752 patent’s expiration in 2016 on a damages award, and the number of products containing infringing proces- sors that were imported into the United States. J.A. 7129‒39. Case: 22-1884 Document: 54 Page: 10 Filed: 08/28/2024

As a result of WARF’s desire to keep the cases separate, and Apple not opposing that request, the district court stayed WARF II pending the outcome of the appeal in WARF I. J.A. 15457. 6 IV After this court’s 2018 Decision, which effectively re- versed the jury verdict finding Apple’s A7 and A8 proces- sors literally infringe the ’752 patent, a briefing schedule was set in both WARF I and WARF II to determine next steps in both proceedings. A With respect to WARF I, WARF requested a new trial on infringement under the doctrine of equivalents. Apple opposed this request, and the district court denied WARF’s request for two reasons. First, it concluded that WARF “abandoned its doctrine of equivalents theory in response to Apple’s agreement not to introduce its newly-acquired patent on a LSD Predictor despite the patent-in-suit to demonstrate that the accused technology was separately patentable and therefore, not equivalent.” Wis. Alumni Rsch. Found., 2022 WL 2080153, at *3 (emphasis omitted). Second, the district court held that WARF’s argument un- der the doctrine of equivalents is precluded as a matter of law because the plain and ordinary meaning of “particular” as determined by this court—“to be associated with a single load instruction”—foreclosed an equivalent where the pre- diction could be associated with a group of load instruc- tions. Id. at *4 (emphases added). In other words, WARF’s doctrine-of-equivalents theory would, according to the dis- trict court, vitiate the claim limitation by rendering

6 The district court had also previously stayed WARF II in part, recognizing that “a final judgment in WARF I will likely have preclusive effect” in WARF II. J.A. 8003. Case: 22-1884 Document: 54 Page: 11 Filed: 08/28/2024

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“particular” meaningless. The district court therefore con- cluded that “WARF I leaves no room for WARF to revisit the doctrine of equivalen[ts] claim it voluntarily aban- doned,” and it denied WARF’s request to pursue a doctrine- of-equivalents theory in WARF I. Id. at *4–5. B With respect to WARF II, WARF sought to continue the case under a doctrine-of-equivalents theory of infringe- ment against Apple’s A9 and A10 processors. Apple op- posed, arguing that our decision in WARF I precluded a finding that A9 and A10 infringe the ’752 patent under multiple preclusion doctrines, including claim preclusion, issue preclusion, the Kessler doctrine, and judicial estoppel. The district court agreed and, relying on Nystrom v. Trex Co., 580 F.3d 1281 (Fed. Cir. 2009) (“Nystrom II”), held that the claims in WARF II were barred by the judg- ment in WARF I. The court reasoned that “the procedural posture of this case is the same as that presented in the Nystrom [II] case, and the Federal Circuit had no trouble concluding . . . that the plaintiff in that case was barred from revisiting a doctrine of equivalents theory of infringe- ment based on waiver of that doctrine in past litigation over materially similar, earlier generation of the same products despite later generations being produced during and after the course of the first litigation.” Wis. Alumni Rsch. Found., 2022 WL 2080153, at *5 (emphasis in origi- nal). Final judgments were thus entered in both WARF I and WARF II. WARF timely appealed both, and we consoli- dated the appeals. We have jurisdiction under 28 U.S.C. § 1295(a)(1). DISCUSSION WARF appeals the final judgments in both WARF I and WARF II. With respect to WARF I, WARF argues that it did not waive its doctrine-of-equivalents theory generally Case: 22-1884 Document: 54 Page: 12 Filed: 08/28/2024

with respect to A7 and A8. With respect to WARF II, WARF argues that issue preclusion does not apply. Apple disagrees with each of WARF’s arguments and further ar- gues that, even if issue preclusion does not apply, the Kess- ler doctrine bars WARF II. We affirm the district court’s conclusion that WARF waived its doctrine-of-equivalents theory in WARF I and thus its denial of WARF’s motion for a new trial. We also affirm, under both issue preclusion and the Kessler doc- trine, the district court’s ruling that WARF I bars WARF II. I We begin with WARF I and whether WARF waived its doctrine-of-equivalents theory. 7 “We apply our law to sub- stantive and procedural issues unique to and intimately in- volved in federal patent law, and we apply regional circuit law to other substantive and procedural issues.” Verinata Health, Inc. v. Ariosa Diagnostics, Inc., 830 F.3d 1335, 1338 (Fed. Cir. 2016). “Waiver is a procedural issue,” but we have held that Federal Circuit law controls where “the un- derlying substance of the arguments is intimately related with the substance of enforcement of a patent right.” Har- ris Corp. v. Ericsson Inc., 417 F.3d 1241, 1250‒51 (Fed. Cir.

7 “Waiver is different from forfeiture. Whereas for- feiture is the failure to make the timely assertion of a right, waiver is the intentional relinquishment or abandonment of a known right.” United States v. Olano, 507 U.S. 725, 733 (1993) (cleaned up); see also In re Google Tech. Hold- ings LLC, 980 F.3d 858, 862–63 (Fed. Cir. 2020). Although some aspects of WARF’s actions (or inactions) in WARF I sound more in forfeiture and others more in waiver, for simplicity—and because any distinction between the two is immaterial to our disposition—we use the term “waiver” in our discussion. Case: 22-1884 Document: 54 Page: 13 Filed: 08/28/2024

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2005) (cleaned up). We “review[] the trial court’s decision on the waiver issue for an abuse of discretion.” United States v. Ziegler Bolt & Parts Co., 111 F.3d 878, 883 (Fed. Cir. 1997). “An abuse of discretion occurs when a court misunderstands or misapplies the relevant law or makes a clearly erroneous finding of fact.” Nat’l Westminster Bank, PLC v. United States, 512 F.3d 1347, 1363 (Fed. Cir. 2008). WARF argues that it “did not and could not have waived” its doctrine-of-equivalents theory in WARF I. Ap- pellant’s Br. 36. WARF argues that it “believed Apple lit- erally infringed” under the plain and ordinary meaning of “particular,” and such claim construction “did not require” a doctrine-of-equivalents theory. Id. Instead, WARF ar- gues that it was Apple who waived a claim construction for the term “particular” in WARF I, that WARF relied on this alleged waiver of a narrower claim construction for the term “particular” in deciding that “it could present only lit- eral infringement at the 2015 trial,” that the narrower con- struction of “particular” “became relevant only after appeal,” and that the narrower construction “foreclosed lit- eral infringement.” Id. at 36‒37 (emphasis omitted). WARF further argues it did not take any actions to waive its doctrine-of-equivalents theory generally, “did not stipu- late to any adverse inferences or judgments against it,” and successfully opposed Apple’s motion for judgment as a mat- ter of law on the doctrine of equivalents on the basis that it was never actually litigated. Id. at 38. Where there has been a change in claim construction as a result of an ap- peal, WARF believes that Exxon Chemical Patents, Inc. v. Lubrizol Corp. controls. 137 F.3d 1475 (Fed. Cir. 1998) (“Exxon II”). Apple presents a different narrative of events—i.e., “WARF made the strategic choice to abandon its [doctrine- of-equivalents] theory in order to prevent Apple from intro- ducing evidence of Apple’s own patent during the trial’s li- ability phase.” Appellee’s Br. 22. Apple relies on this court’s 2018 Decision for support, arguing (1) we expressly Case: 22-1884 Document: 54 Page: 14 Filed: 08/28/2024

acknowledged that “WARF abandoned its theory of in- fringement under the doctrine of equivalents before trial,” and (2) we reversed without remand for further proceed- ings, such that the district court must follow that mandate. Id. at 22‒24 (quoting 2018 Decision, 905 F.3d at 1347 n.5). Apple further asserts that this court “did not adopt a new claim construction” and thus argues that Exxon II does not apply. Id. at 24‒29. For the reasons below, we agree with the district court that WARF waived its doctrine-of-equivalents theory in WARF I. In particular, we conclude that (1) no change in the claim construction excused WARF’s failure to present its doctrine-of-equivalents theory to the jury in WARF I; (2) in fact, WARF affirmatively abandoned that theory for strategic purposes unrelated to claim construction; and (3) for each of these reasons, our holding in Exxon II does not help WARF. A We begin with WARF’s argument that our 2018 Deci- sion adopted a claim construction for the term “particular” that was different from what had previously been advanced or understood as the proper construction in the WARF I trial. Whether our 2018 Decision changed the claim con- struction is not the correct inquiry. The correct inquiry is whether the claim construction changed in a way that would excuse WARF’s failure to raise, at the previous trial, the doctrine-of-equivalents theory that it now attempts to reassert in WARF I. We find under the facts here that it did not. Our 2018 Decision clarified the plain and ordinary meaning of “particular,” the meaning of which was wholly consistent with Apple’s understanding of the plain and or- dinary meaning of the term before and during trial. 2018 Decision, 905 F.3d at 1348 (“Giving a term its plain and ordinary meaning does not leave the term devoid of any meaning whatsoever.”). For example, by at least March Case: 22-1884 Document: 54 Page: 15 Filed: 08/28/2024

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2015 (six months before trial), Apple set forth a nonin- fringement defense in its expert report that argued, even under the plain and ordinary meaning of “particular,” a “‘prediction’ must be associated with a single load instruc- tion (i.e., one and only one load instruction), rather than with a group of load instructions.” Id. at 1347 (emphases in original). And during trial, when WARF moved to ex- clude Apple’s noninfringement defense as inconsistent with the plain and ordinary meaning of “particular,” the district court disagreed and denied WARF’s motion “be- cause Apple’s non-infringement argument . . . was con- sistent with the plain meaning of ‘particular’ as contemplating association with a single load instruction.” Wis. Alumni Rsch. Found., 2022 WL 2080153, at *2. These examples demonstrate Apple’s consistent understanding of the plain and ordinary meaning of “particular”—an under- standing that persisted through Apple’s trial presentation in WARF I and that is substantively equivalent to the 2018 Decision’s articulation of the plain and ordinary meaning of “particular.” Moreover, WARF was not foreclosed from raising the doctrine of equivalents at trial as an alternative to literal infringement given Apple’s noninfringement position. Ra- ther, WARF subjectively “believed [that] Apple literally in- fringed” such that it “did not require” a doctrine-of- equivalents theory. Appellant’s Br. 36. That confidence in the strength of its literal infringement theory does not ex- cuse WARF from failing to litigate the doctrine of equiva- lents. Similarly, WARF’s argument that our 2018 Decision foreclosed WARF only from pursuing a theory of literal in- fringement is unavailing because it is irrelevant to whether WARF waived its right to assert a doctrine-of-equivalents theory. Id. at 36–37. Indeed, WARF asserts that “[i]f Ap- ple had timely requested and received the narrower ‘one and only one’ construction that it later sought and obtained for the first time on appeal . . . then WARF would have cer- tainly pursued an infringement claim under the [doctrine Case: 22-1884 Document: 54 Page: 16 Filed: 08/28/2024

of equivalents] at trial.” Id. at 36. But Apple had asserted its understanding of the plain and ordinary meaning of “particular” (as one and only one) since well before trial in its expert reports, such that WARF could have raised, and had ample incentive to raise, the doctrine of equivalents at trial under the same theory it attempts to resurrect now. B We also conclude that WARF separately, and for rea- sons unrelated to claim construction, waived its doctrine- of-equivalents theory. “Waiver is the intentional relinquishment or abandon- ment of a known right.” Olano, 507 U.S. at 733 (cleaned up). “[F]ail[ing] to present substantive arguments to the district court concerning infringement under the doctrine of equivalents” constitutes a waiver of the issue. Boss Con- trol, Inc. v. Bombardier Inc., 410 F.3d 1372, 1380 (Fed. Cir. 2005); see also United States v. Hible, 700 F.3d 958, 961 (7th Cir. 2012) (finding waiver when a party “for strategic reasons elects to pursue one argument while foregoing an- other” (cleaned up)). While WARF attempts to recharacterize its reasons for not pursing the doctrine of equivalents in WARF I, the rec- ord speaks for itself: before the WARF I trial, WARF inten- tionally relinquished and abandoned its doctrine-of- equivalents theory in exchange for Apple’s agreement not to present its own patent at trial. J.A. 15290 (explaining that WARF had “agreed to ‘drop doctrine of equivalen[ts] and make no doctrine of equivalents arguments whatsoever at trial’” (emphasis added)). This was a relinquishment of a known right. As a result of the parties’ bargained-for ex- change, the district court ordered that “neither side may introduce evidence or argument regarding [Apple’s pa- tent] . . . during the liability phase of trial.” J.A. 15294. Moreover, when WARF struck this bargain and dropped its doctrine-of-equivalents theory, and indeed throughout the district court proceedings, both WARF and Apple retained Case: 22-1884 Document: 54 Page: 17 Filed: 08/28/2024

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their ability to argue their positions on what the plain and ordinary meaning required or allowed. The incentive for preserving a doctrine-of-equivalents theory persisted through trial, and WARF dropped that theory for reasons independent of that incentive. WARF essentially asks this court to allow WARF to re- litigate WARF I under a doctrine-of-equivalents theory that would have been available and realistically useful to it in WARF I in essentially the same form as it is today. We find that WARF’s abandonment of the doctrine of equiva- lents forecloses this result. C Finally, we disagree that Exxon II applies to the cir- cumstances here. WARF argues that this case stands for the proposition that “when the doctrine of equivalents be- comes a critical issue only after a new claim construction is adopted on appeal, a plaintiff’s prior choice to not present that theory at trial does not constitute abandonment.” Ap- pellant’s Br. 38. WARF’s understanding of the holding of Exxon II is too broad. There, Exxon sued Lubrizol for patent infringement. The parties disputed how to interpret the claims. Under Exxon’s read, the patent claims were like a “recipe” of in- gredients that extended to any product made by using the claimed ingredients; Lubrizol, on the other hand, argued that the claims were directed to the composition of the final product. Exxon Chem. Pats., Inc. v. Lubrizol Corp., 64 F.3d 1553, 1555 (Fed. Cir. 1995) (“Exxon I”). The district court did not decide which claim construction was correct “until all the evidence was in, just before the case was submitted to the jury.” Id. at 1561. Thus, during trial, Exxon “had the choice of simply proving infringement under its view of the claims, or in addition proving infringement under Lubrizol’s view as well. Exxon chose to do both.” Id. at 1559 (emphasis omitted). After the evidence was pre- sented, the judge charged the jury under Exxon’s view of Case: 22-1884 Document: 54 Page: 18 Filed: 08/28/2024

the claims as a “recipe.” Id. at 1555. Exxon then chose to stop pursuing its doctrine-of-equivalents theory. See Exxon II, 137 F.3d at 1477. “To find infringement as charged, all the jury had to find is that Lubrizol used Exxon’s claimed starting ingredients in the amount claimed, an essentially uncontested fact.” Exxon I, 64 F.3d at 1559 n.5. In other words, “[o]nce the district judge construed the claim lan- guage in Exxon’s favor, the doctrine-of-equivalents issue in the case became moot.” Exxon II, 137 F.3d at 1479. The jury found Lubrizol infringed Exxon’s patents. On a first appeal, we concluded that the correct claim construction was a third option—one that, while partially based on Lubrizol’s construction, was neither party’s pro- posed construction in full. Exxon I, 64 F.3d at 1555; Exxon II, 137 F.3d at 1477. We then “held that under the correct claim interpretation no reasonable jury could have found that Lubrizol’s products literally infringed Exxon’s patent,” and we reversed the judgment of the district court. Exxon II, 137 F.3d at 1477. Back at the district court, Exxon moved for a new trial on the doctrine of equivalents, but the district court denied the motion, stating it had “no authority to grant a new trial.” Id. Exxon filed a second appeal, “arguing that although our reversal of the jury verdict foreclosed any further pro- ceedings relating to literal infringement, our mandate did not preclude the district court from entertaining a motion for a new trial on the issue of infringement under the doc- trine of equivalents.” Id. at 1477‒78. We agreed, explain- ing that “in determining that Lubrizol did not literally infringe Exxon’s patent [in Exxon I], this court did not dis- pose of Exxon’s doctrine-of-equivalents infringement claim.” Id. at 1478. The question in Exxon II was “what the appellate court’s mandate left for the district court to do.” Id. at 1482. We decided that the district court could consider a motion for a new trial, and “we le[ft] to the dis- trict court the questions whether Exxon is entitled to a new trial on th[e] [doctrine-of-equivalents] theory and whether Case: 22-1884 Document: 54 Page: 19 Filed: 08/28/2024

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there is any procedural flaw in Exxon’s motion that would prevent the district court from considering the motion on its merits.” Id. at 1483. At a bird’s eye view, there are similarities between Exxon I and II and the facts before us, but there are critical differences. First, while the district court’s claim construc- tion charge to the jury rendered Exxon’s doctrine-of-equiv- alents theory moot, here there was no such mootness. Id. at 1479. In other words, while there was no reason for the jury to consider Exxon’s doctrine-of-equivalents theory un- der the uncontested facts, here, in contrast, there were rea- sons for WARF to pursue its doctrine-of-equivalents theory—namely, the parties were actively disputing the scope of the plain and ordinary meaning of “particular” be- fore, during, and after trial. And the district court had in- formed WARF that Apple’s noninfringement defense (under what WARF calls a narrower construction of the plain and ordinary meaning) “was consistent with the plain meaning of ‘particular.’” Wis. Alumni Rsch. Found., 2022 WL 2080153, at *2. Therefore, the dispute on this term was not moot. And while we explained in Exxon II that Exxon “could not realistically be expected to request alter- native jury instructions asking for an advisory verdict on whether the patent would be infringed under the doctrine of equivalents on Lubrizol’s proposed claim construction,” Exxon II, 137 F.3d at 1479, the same is not true here. Pro- ceeding on the doctrine of equivalents in WARF I would not have resulted in a mere “advisory verdict.” Second, unlike Exxon I and II, WARF affirmatively abandoned its doctrine-of-equivalents theory. In Exxon II, we explained that, because the doctrine-of-equivalents the- ory became moot, Exxon had not “abandoned [that] theory of liability by not submitting it to the jury or raising it on the previous appeal.” Id. at 1478–79. Here, WARF aban- doned its doctrine-of-equivalents theory in a quid-pro-quo exchange where Apple agreed not to present evidence of its Case: 22-1884 Document: 54 Page: 20 Filed: 08/28/2024

patent at trial—not in reliance on a particular claim con- struction that mooted any doctrine-of-equivalents theory. Third, Exxon II “simply [held] that our prior mandate did not deprive the district court of the authority to enter- tain the motion [for a new trial].” Id. at 1483. Exxon II did not grant a per se right to a new trial on the doctrine of equivalents as WARF appears to suggest. Here, the dis- trict court considered WARF’s motion for a new trial on the doctrine of equivalents but disagreed that WARF’s motion should be granted. Indeed, the district court agreed that Exxon II “allow[ed] an opening for a claim of infringe- ment under the doctrine of equivalents” but “did not dictate th[at] result.” Wis. Alumni Rsch. Found., 2022 WL 2080153, at *3 (emphasis in original). Upon consideration of the facts here, the district court determined WARF was not entitled to a new trial because it had abandoned its doc- trine-of-equivalents theory. Id. at *4. 8 The district court’s consideration of the motion, and its denial of that motion due to the “procedural flaw” of WARF’s previous waiver, was not inconsistent with Exxon II. See 137 F.3d at 1483. For the reasons above, the district court did not err in finding that WARF waived its doctrine-of-equivalents the- ory in WARF I. We therefore affirm its denial of WARF’s motion for a new trial.

8 The district court also determined that our prior appellate ruling as to the plain and ordinary meaning of “particular” “precludes as a matter of law” WARF’s doc- trine-of-equivalents theory of infringement. Wis. Alumni Rsch. Found., 2022 WL 2080153, at *4. Due to the sua sponte nature of this claim vitiation determination, which the parties had no opportunity to brief, we do not rely on this analysis. Case: 22-1884 Document: 54 Page: 21 Filed: 08/28/2024

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II We next turn to WARF II and the question of whether WARF I precludes WARF from pursuing a doctrine-of- equivalents theory in WARF II. We conclude that it does. As stated above, we affirm the district court’s judgment as to WARF II based on issue preclusion and the Kessler doc- trine. We address each in turn below. A “We apply the law of the regional circuit to the general procedural question of whether issue preclusion applies.” Soverain Software LLC v. Victoria’s Secret Direct Brand Mgmt., LLC, 778 F.3d 1311, 1314 (Fed. Cir. 2015). “We apply this court’s precedent to questions involving substan- tive issues of patent law, issues of issue preclusion that im- plicate substantive patent law issues, or issues of issue preclusion that implicate the scope of our own previous de- cisions.” Id. Whether issue preclusion applies is a legal question reviewed de novo. Bernstein v. Bankert, 733 F.3d 190, 225 (7th Cir. 2013). Underlying factual findings are reviewed “under the highly deferential clear error stand- ard.” Goodpaster v. City of Indianapolis, 736 F.3d 1060, 1070 (7th Cir. 2013). Clear error exists when “the trial judge’s interpretation of the facts is implausible, illogical, internally inconsistent or contradicted by documentary or other extrinsic evidence.” Id. (cleaned up). Issue preclusion, sometimes called collateral estoppel, requires that “(1) the issue sought to be precluded is the same as that involved in a prior action; (2) the issue was actually litigated; (3) the determination of the issue was es- sential to the final judgment; and (4) the party against whom estoppel is invoked was represented in the prior ac- tion.” Adair v. Sherman, 230 F.3d 890, 893 (7th Cir. 2000); see also Soverain Software, 778 F.3d at 1315. The dispute between the parties here relates only to el- ements (1) and (2), which requires an answer to the Case: 22-1884 Document: 54 Page: 22 Filed: 08/28/2024

threshold question—what is the “issue”? WARF defines the issue in WARF I as “whether Apple’s A7 and A8 proces- sors literally infringe the ’752 patent” and the issue in WARF II as “whether Apple’s A9 and A10 processors in- fringe the ’752 patent under the [doctrine of equivalents].” Appellant’s Br. 28. Apple defines the issue as the same in both cases—“whether Apple’s accused products infringe the ’752 patent.” Appellee’s Br. 41. The differences be- tween these two characterizations of “the issue” require us to determine whether, for the purposes of issue preclusion, the A7/A8 and A9/A10 processors are “essentially the same” and whether literal infringement and the doctrine of equivalents are part of the same overall issue of infringe- ment. 1 Issue preclusion may apply and bar a second litigation, even where the products are different from the first litiga- tion, under “limited circumstances where it is shown that a close identity exists between the relevant features of the accused device and the device previously determined to be non-infringing such that they are essentially the same.” ArcelorMittal Atlantique et Lorraine v. AK Steel Corp., 908 F.3d 1267, 1274 (Fed. Cir. 2018) (cleaned up). “Accused de- vices are essentially the same where the differences be- tween them are merely colorable or unrelated to the limitations in the claim of the patent.” Id. (cleaned up). We find no clear error in the district court’s finding that the LSD Predictors in the A7/A8 and the A9/A10 processors are essentially the same. See Wis. Alumni Rsch. Found., 2022 WL 2080153, at *3 (“There is no dispute that the LSD Predictor technology at issue in this second lawsuit, WARF II, is the same as that at issue in WARF I, at least as ma- terial to plaintiff’s renewed infringement claims under the ’752 patent.”). While framed as an issue not in dispute by the district court, WARF argues that “the district court . . . erred in apparently concluding that the A9 and A10 Case: 22-1884 Document: 54 Page: 23 Filed: 08/28/2024

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processors were essentially the same as the A7 and A8 pro- cessors at issue in WARF I.” Appellant’s Br. 27. Yet WARF waffles on whether it disputes that the A7/A8 and A9/A10 processors are essentially the same. For example, in WARF’s opening brief, WARF does not appear to dispute that A7/A8 and A9/A10 are essentially the same for the purposes of issue preclusion (instead, it focuses on whether literal infringement and the doctrine of equiva- lents are the same issue). See id. at 28–36. Likewise, in reply, WARF again relies on the distinction between literal infringement and the doctrine of equivalents even in rebut- ting Apple’s argument that the products are essentially the same. See Appellant’s Reply Br. 11 n.2 (“Apple suggests issue preclusion turns on whether the accused products in the later case are ‘essentially the same’ as those in the ear- lier case. . . . But that only holds if all of the other require- ments of issue preclusion are also met, including that the identical issue was actually litigated.” (emphasis in origi- nal)). Similarly, WARF quotes its June 2017 briefing on the potential consolidation of WARF I and II, saying “Apple represented that it would not dispute that the [A9] and A10 chips are not more than colorably different” and adding that this is “not inconsistent with WARF’s positions.” Id. at 29–30 (emphasis omitted). Yet, when asked at oral ar- gument whether WARF was still disputing whether A7/A8 and A9/A10 are essentially the same, WARF indicated it was. Oral Arg. at 1:06‒9:24; see also id. at 18:40–21:00. 9 At any rate, a generous read of WARF’s briefing reveals just two possible arguments for why the A7/A8 and A9/A10 processors may not be essentially the same: (1) “Apple pro- vided no discovery on the A9 and A10 processors,”

9 Nos. 22-1884, -1866, https://oralarguments.cafc.us courts.gov/default.aspx?fl=22-1884_06032024.mp3. Case: 22-1884 Document: 54 Page: 24 Filed: 08/28/2024

Appellant’s Br. 27 (citing J.A. 15106); 10 and (2) there was a potential “significant change involving the [LSD] Predic- tor” in the later A9 and A10 processors from the earlier A7 and A8 processors. Id. at 9 (emphasis omitted). Neither argument is persuasive. Apple was initially able to resist discovery on A9 and A10 as part of WARF I, resulting ulti- mately in the filing of WARF II. J.A. 15129. At that time, in October 2014, before the development of A9 and A10 was complete, Apple indeed represented certain design changes were being contemplated for the LSD Predictor in A9 and A10. Appellant’s Br. 9. But this was not the end of the story. A year later in late 2015, after WARF had won a jury verdict on infringement, WARF moved for equitable relief, repeatedly stating that A9 used “the same infringing LSD Predictor design” as A7 and A8. See J.A. 7005–06, 7008. Apple also admitted in post-trial briefing that “the LSD Predictor contained in the A9 and A9X products is not more than colorably different . . . from the LSD Predictor in the A7, A8, and A8X products that were addressed at trial” and agreed to produce financial information on A9 for the calculation of damages in WARF I. J.A. 7046; see also J.A. 7127 (same). In 2017 (by which time A10 had been accused in WARF II), WARF and Apple again agreed that the A9 and A10 processors were not more than colorably different. J.A. 7129–30 (“The parties are now working to- gether to formulate a stipulation to this effect . . . .”). WARF contends, however, that it did not want WARF I and II consolidated after trial in WARF I because more discovery was necessary for A9 and A10. Appellant’s Reply Br. 6. But the only discovery WARF still needed was

10 Apple disputes the merits of this argument, ex- plaining that source code for A9 was produced, WARF’s ex- pert reviewed that source code, and a declaration and other documents about A9 and A10 were produced. Oral Arg. at 41:43–43:29. Case: 22-1884 Document: 54 Page: 25 Filed: 08/28/2024

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damages-related discovery—not technical discovery for the purposes of determining the products were essentially the same. See J.A. 7129–39 (never once mentioning the need for additional technical discovery). Indeed, WARF ex- plained its preference to keep WARF I and II separated as follows: The second case [WARF II], which concerns Apple’s A9, A9X, A10, A10X and later processors, should not be consolidated and should remain stayed pending resolution of Apple’s appeal in [WARF I]. Should WARF prevail on appeal, then the task of calculating the numbers of infringing units of these processors can resume in [WARF II] once the stay is lifted. Conversely, should Apple prevail on ap- peal, there may be no need for such calculations. J.A. 7130 (emphasis added); see also J.A. 7149 (Apple again agreeing damages may be awarded at the same rates for the A9/A10 as the A7/A8 LSD Predictors because they are not more than colorably different); see also J.A. 7187–7208 (same). Further still, in 2019, Apple con- firmed with source code and an Apple engineer’s declara- tion supporting the conclusion that “all of the chips at issue in these two cases contain the same accused feature—the LSD Predictor using hashed load tags.” Appellee’s Br. 34 (quoting Wis. Alumni Rsch. Found., 2022 WL 2080153, at *3). From 2015 until the filing of this appeal, WARF has not disputed that the A7/A8 and A9/A10 LSD Predictors are essentially the same. It is simply not credible to rely on statements made while the products were still under de- velopment in 2014 and ignore all of the parties’ statements and evidence after the products were developed from 2015 to today. We therefore conclude that the district court did not err in finding that the A7/A8 and A9/A10 processors are essentially the same. Case: 22-1884 Document: 54 Page: 26 Filed: 08/28/2024

2 Having settled that WARF I and II raise infringement allegations against essentially the same products, the only other difference between WARF’s and Apple’s articulation of “the issue” is whether the issue is infringement or the separate theories of infringement. WARF correctly states that the issue “actually liti- gated” in the first action must be “identical” to the issue in the second action for issue preclusion to apply. Appellant’s Br. 28. WARF quotes B & B Hardware, Inc. v. Hargis In- dustries, Inc. for the proposition that “[i]ssues are not iden- tical if the second action involves application of a different legal standard, even though the factual setting of both suits may be the same.” 575 U.S. 138, 154 (2015) (quoting 18 C. Wright, A. Miller, & E. Cooper, Federal Practice & Proce- dure § 4417, p. 449 (2d ed. 2002)). WARF then concludes that because literal infringement and the doctrine of equiv- alents have different tests, they must be different issues. But WARF reads this statement in B & B Hardware too broadly. In B & B Hardware, the dispute was about whether a Trademark Trial and Appeal Board (“TTAB”) decision could have preclusive effect on a district court proceeding. In trademark law, a party may seek to register a trade- mark with the Patent and Trademark Office (“PTO”). If another entity believes the to-be-registered trademark would be too similar to its own trademark, it may oppose the registration before the TTAB in an administrative pro- ceeding. Separately, that entity may also file a trademark infringement suit in district court. Both proceedings, au- thorized by two different statutes, look to whether there would be a “likelihood of confusion” between the two trade- marks. Compare 15 U.S.C. § 1052(d) (PTO registration permissibility), with § 1114(1) (district court trademark in- fringement liability). The Supreme Court held that TTAB proceedings did have preclusive effect on district-court Case: 22-1884 Document: 54 Page: 27 Filed: 08/28/2024

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trademark-infringement suits and concluded that “the same likelihood-of-confusion standard applies to both reg- istration and infringement” even though they arise from different statutory authority and apply different factors to assess “likelihood of confusion.” B & B Hardware, 575 U.S. at 154. The Court explained that “minor variations in the application of what is in essence the same legal standard do not defeat preclusion.” Id. (cleaned up). Critical here, B & B Hardware does not hold that the factors or tests must be identical for issues to be identical. Indeed, the “likelihood of confusion” factors at the TTAB were different from (albeit similar to) those in district-court proceedings. Id. For this reason, WARF reads B & B Hard- ware too broadly, and WARF’s mere observation that the tests for literal infringement and the doctrine of equiva- lents are different is insufficient to demonstrate that the issues are different. See Appellant’s Br. 29–30. Instead, the Court concluded that the legal standards were the same in B & B Hardware, giving reasons for that conclusion that are relevant here: (1) “the operative lan- guage [of the two statutes] is essentially the same”; (2) “the likelihood-of-confusion language . . . has been central to trademark registration since at least 1881”; and (3) the Re- statement (Second) of Judgments supported the conclusion that the issues were the same. B & B Hardware, 575 U.S. at 148, 154–55, 157. In other words, the Court looked to the statutes, the history, and the Restatement (Second) of Judgments. Id. at 148, 153, 157. We take the same ap- proach. Here there is only one statute governing patent in- fringement. See 35 U.S.C. § 271. Section 271(a) provides that “whoever without authority makes, uses, offers to sell, or sells any patented invention, within the United States or imports into the United States any patented invention during the term of the patent therefor, infringes the Case: 22-1884 Document: 54 Page: 28 Filed: 08/28/2024

patent.” 11 This is the statutory basis for direct infringe- ment, which covers both literal infringement and the doc- trine of equivalents. Thus, unlike B & B Hardware, we are not dealing with two statutes, just one describing liability for all direct infringement. As to history, the statute and the derivation of the doc- trine of equivalents demonstrate that the doctrine of equiv- alents is a long-established theory of infringement. Liability for patent infringement was first enacted in the Patent Act of 1790. By 1853, the Supreme Court recog- nized a patentee may prevail on a theory of infringement where the accused device “substantially . . . embod[ies] the patentee’s mode of operation, and thereby attain[s] the same kind of result as was reached by his invention”— thereby laying the foundation for what today is the doc- trine of equivalents. Winans v. Denmead, 56 U.S. 330, 344 (1853); see also Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 608 (1950) (articulating the now familiar test for the doctrine of equivalents). 12 Both Graver Tank and Winans treated infringement, either literal or doctrine of equivalents, as a single issue. See Graver Tank, 339 U.S. at 607 (considering the “issue” under both the doctrine of equivalents and literal infringement and noting that “the single issue before us is whether the trial court’s holding that the . . . claims have been infringed will be sustained” (emphasis added)); Winans, 56 U.S. at 343 (“How is a

11 Other sections of § 271 provide the basis for other types of infringement not at issue here, such as induced and contributory infringement. See 35 U.S.C. § 271(b)–(c). 12 “A patentee may invoke this doctrine to proceed against the producer of a device if it performs substantially the same function in substantially the same way to obtain the same result.” Graver Tank, 339 U.S. at 608 (cleaned up). Case: 22-1884 Document: 54 Page: 29 Filed: 08/28/2024

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question of infringement of this patent to be tried?” (empha- sis added)). 13 The Restatement (Second) of Judgments § 27 also pro- vides guidance on the scope of the “issue” here as it did in B & B Hardware. Indeed, the Restatement (Second) of Judgments contemplates the difficulties in defining the “is- sue” for purposes of issue preclusion: When there is a lack of total identity between the particular matter presented in the second action and that presented in the first, there are several factors that should be considered in deciding whether for purposes of the rule of this Section the “issue” in the two proceedings is the same, for ex- ample: Is there a substantial overlap between the

13 Underscoring this is the Supreme Court’s recogni- tion that the doctrine of equivalents is limited to covering products or processes that are at most insubstantially dif- ferent from what would literally infringe a patent claim. See Graver Tank, 339 U.S. at 607 (noting that allowing re- covery only under strict literal infringement “would leave room for—indeed encourage—the unscrupulous copyist to make unimportant and insubstantial changes and substi- tutions in the patent which, though adding nothing, would be enough to take the copied matter outside the claim, and hence outside the reach of law” (emphasis added)). In B & B Hardware, a trademark case, the Court explained that “trivial variations between the usages set out in an application [for registration] and the use of a mark in the marketplace do not create different ‘issues,’ just as trivial variations do not create different ‘marks.’” 575 U.S. at 157. A same-issue conclusion is likewise warranted for an asser- tion of patent infringement under the doctrine of equiva- lents, which is necessarily an assertion that the accused product or process is at most insubstantially different from what the patent claim at issue literally sets out. Case: 22-1884 Document: 54 Page: 30 Filed: 08/28/2024

evidence or argument to be advanced in the second proceeding and that advanced in the first? Does the new evidence or argument involve application of the same rule of law as that involved in the prior proceeding? Could pretrial preparation and discov- ery relating to the matter presented in the first ac- tion reasonably be expected to have embraced the matter sought to be presented in the second? How closely related are the claims involved in the two proceedings? Restatement (Second) of Judgments § 27 cmt. c (AM. L. INST. 1982). Here, the evidence would be substantially the same between literal infringement and the doctrine of equivalents; it will always boil down to the patent claim, the accused product (or method), and a comparison of the two. Indeed, the evidence must necessarily be substan- tially the same because the doctrine of equivalents is in- tended to cover “unimportant and insubstantial changes and substitutions in the patent which, though adding noth- ing, would be enough to take the copied matter outside the claim.” Graver Tank, 339 U.S. at 607 (emphases added). Further, and for essentially the same reason, it is hardly disputable that pretrial preparation and discovery in a pa- tent suit could be “reasonably expected” to embrace both literal infringement and the doctrine of equivalents. Finally, we note that treating literal infringement and the doctrine of equivalents as the same issue is consistent with our precedent. For example, in Nystrom II, Nystrom filed a first lawsuit, alleging Trex’s first-generation “Trex boards” infringed Nystrom’s patent. After claim construc- tion, Nystrom stipulated to noninfringement, and the dis- trict court entered judgment accordingly. We affirmed this judgment but remanded for further proceedings on valid- ity. “On remand, Nystrom attempted to pursue his in- fringement claim under the doctrine of equivalents.” Nystrom II, 580 F.3d at 1284. The district court deter- mined the doctrine of equivalents had been waived. Id. Case: 22-1884 Document: 54 Page: 31 Filed: 08/28/2024

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Thereafter, Nystrom filed a second lawsuit, accusing sec- ond-generation products (that were essentially the same as the first-generation products) of infringing the same patent under the doctrine of equivalents. We held this second suit barred by the first. Id. at 1286. And we clarified, in Aspex Eyewear, Inc. v. Marchon Eyewear, Inc., that Nystrom II applied issue preclusion to reach this result. 14 672 F.3d 1335, 1343 (Fed. Cir. 2012); cf. ArcelorMittal, 908 F.3d at 1273 (explaining that even though a first lawsuit found noninfringement under the doctrine of equivalents, a sec- ond lawsuit on infringement would be barred if the prod- ucts in both suits were “materially” the same). 15 For the foregoing reasons, we are convinced that literal infringement and the doctrine of equivalents are the same issue for issue-preclusion purposes. To conclude otherwise would allow a patentee to proceed through the entirety of litigation only on a theory of literal infringement and, after losing its case, allow that same party to accuse the same entity of infringing the same patent, accusing the same or essentially the same products, as long as those products were sold after judgment of the first suit. See Galderma

14 At oral argument, WARF agreed that the stipula- tion to noninfringement in Nystrom II “necessarily em- braced” both literal infringement and the doctrine of equivalents. See Oral Arg. at 30:11–32:03. Such an admis- sion implicitly concedes that the issue of infringement nec- essarily embraces both underlying theories. 15 At oral argument, WARF also argued that Exxon I and II demonstrate that literal infringement and the doc- trine of equivalents are different issues. Oral Arg. at 25:11–26:35, 29:00–30:11, 32:03–32:32. We disagree. Exxon I and II involved a single case, meaning there was no possibility that a final judgment in one case could pre- clude an issue in another. In contrast, the appeal before us involves multiple, repetitious lawsuits. Case: 22-1884 Document: 54 Page: 32 Filed: 08/28/2024

Labs., L.P. v. Amneal Pharms., LLC, 337 F. Supp. 3d. 371, 411 (D. Del. 2018) (Stark, J.) (treating literal and doctrine- of-equivalents infringement as a single issue because not doing so would “upend[] the finality of judgements that col- lateral estoppel aims to preserve and would require parties to relitigate infringement of the same products covered by the same patents when the issue of infringement has al- ready been decided – a decidedly wasteful use of judicial resources.”), rev’d in part on other grounds, 806 F. App’x. 1007 (Fed. Cir. 2020). Such a repetitious litigation strategy is untenable. Therefore, like Nystrom II, when the district court en- tered a judgment of noninfringement in WARF I, issue pre- clusion barred WARF II which accuses essentially the same products of infringement. B Additionally, WARF II is barred by the Kessler doc- trine. See Kessler v. Eldred, 206 U.S. 285 (1907). Kessler is a patent-specific preclusion doctrine that “fills the gap between [claim and issue] preclusion doc- trines . . . allowing an adjudged non-infringer to avoid re- peated harassment for continuing its business as usual post-final judgment.” Brain Life, LLC v. Elekta Inc., 746 F.3d 1045, 1056 (Fed. Cir. 2014) (emphasis omitted). In Kessler, Eldred filed a patent infringement suit against Kessler. The district court and the court of appeals deter- mined that Kessler did not infringe. Eldred then filed a second patent suit against Kessler’s customer for infringe- ment of the same patent. The Supreme Court deemed the second suit barred, explaining that the first action “settled finally and everywhere . . . that Kessler had the right to manufacture, use, and sell the [accused product].” Kessler, 206 U.S. at 288; see also Rubber Tire Wheel Co. v. Goodyear Tire & Rubber Co., 232 U.S. 413, 418 (1914) (under Kessler, a prevailing non-infringer obtains “the right to have that which it lawfully produces freely bought and sold without Case: 22-1884 Document: 54 Page: 33 Filed: 08/28/2024

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restraint or interference”). The Supreme Court explained that the right “attaches to its product—to a particular thing—as an article of lawful commerce.” Rubber Tire Wheel, 232 U.S. at 418. Likewise, we too have held that Kessler operates to grant a product a noninfringing status. The principle that, when an alleged infringer pre- vails in demonstrating noninfringement, the spe- cific accused device(s) acquires the “status” of a noninfringing device vis-à-vis the asserted patent claims is an essential fact of a patent infringement claim. The status of an infringer is derived from the status imposed on the thing that is embraced by the asserted patent claims. And, when the de- vices in the first and second suits are “essentially the same,” the “new” product(s) also acquires the status of a noninfringing device vis-à-vis the same accusing party or its privies. Brain Life, 746 F.3d at 1057 (cleaned up). We have applied the Kessler doctrine in limited circum- stances. 16 For example, in Brain Life we deemed a second suit asserting method claims barred where the patent owner had proceeded to trial solely on apparatus claims in

16 We have previously questioned “whether the Kess- ler doctrine was created as an exception to the mutuality of estoppel rule that existed at the time or as a matter of sub- stantive patent law.” SpeedTrack Inc. v. Off. Depot, Inc., 791 F.3d 1317, 1329 (Fed. Cir. 2015); see also MGA, Inc. v. Gen. Motors Corp., 827 F.2d 729, 733–34 (Fed. Cir. 1987); Brain Life, 746 F.3d at 1058. “But, the Kessler Doctrine exists, and we are bound by it . . . .” Brain Life, 746 F.3d at 1058. “[W]e must follow Kessler unless and until the Su- preme Court overrules it . . . .” SpeedTrack, 791 F.3d at 1329. Until then, “[w]e may only apply the law as it con- tinues to exist.” Brain Life, 746 F.3d at 1058. Case: 22-1884 Document: 54 Page: 34 Filed: 08/28/2024

a first lawsuit. Id. at 1050. We explained that “[w]hile [the original plaintiff] ultimately abandoned the method claims prior to trial, it could have continued to assert those claims. Thus, once the accused devices . . . were adjudged to be noninfringing with respect to the asserted claims and judg- ment was entered as to all claims, [the defendant] was free to continue engaging in the accused commercial activity as a non-infringer.” Id. at 1058. We determined this applied even where the second lawsuit was directed to allegations of infringement for subsequent versions of the originally accused products because there were “no material differ- ences between the currently accused products and the pre- viously adjudicated non-infringing products.” Id. (cleaned up). As a second example, in SpeedTrack, the plaintiff orig- inally asserted only literal infringement in its contentions. See SpeedTrack, 791 F.3d at 1320. When the defendant moved for summary judgment of noninfringement, Speed- Track simultaneously moved to amend its infringement contentions to assert the doctrine of equivalents. Id. SpeedTrack’s motion for leave to amend was denied be- cause “SpeedTrack had actually been on notice of defend- ants’ non-infringement argument” for nearly six months. Id. The district court entered a judgment of noninfringe- ment in the first suit, but SpeedTrack filed a second law- suit, alleging infringement of the same product under the doctrine of equivalents. Id. at 1320–21. The district court deemed the second lawsuit barred by the Kessler doctrine, and we affirmed. Id. at 1329. We explained: [T]he Kessler doctrine is a necessary supplement to issue and claim preclusion: without it, a patent owner could sue a manufacturer for literal infringe- ment and, if unsuccessful, file suit against the manufacturer’s customers under the doctrine of equivalents. Or, a patent owner could file suit against the manufacturer’s customers under any claim or theory not actually litigated against the Case: 22-1884 Document: 54 Page: 35 Filed: 08/28/2024

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manufacturer as long as it challenged only those acts of infringement that post-dated the judgment in the first action. That result would authorize the type of harassment the Supreme Court sought to prevent in Kessler . . . . Id. at 1328. WARF II presents exactly this type of litigation harassment, applied to a second suit against the very same defendant, the manufacturer itself. 17 There is little relevant difference between SpeedTrack and the facts here except that SpeedTrack’s second suit ac- cused the same software as the first suit, id. at 1321, whereas here WARF has accused subsequent versions of the originally accused products. But this difference is im- material. As explained above, Brain Life concluded that the “non-infringing status” applies to subsequent versions of the originally accused products if there are “no material differences” between the accused products in each suit. Brain Life, 746 F.3d at 1058. Therefore, like in Speed- Track, the Kessler doctrine bars WARF’s second lawsuit against essentially the same products. WARF does not respond to SpeedTrack and argues only that Kessler does not apply because we have “relied on the Kessler doctrine only to bar assertion of the claims at issue against essentially the same products made or sold after the judgment of noninfringement in the earlier case.” Ap- pellant’s Reply Br. 13 (emphases omitted) (quoting Sim- pleAir, Inc. v. Google LLC, 884 F.3d 1160, 1170 (Fed. Cir.

17 As we explained in SpeedTrack, had the product manufacturer been a party to the second action, there would be “no doubt” that “the facts here would fall squarely within Kessler.” SpeedTrack, 791 F.3d at 1324. Case: 22-1884 Document: 54 Page: 36 Filed: 08/28/2024

2018)). 18 WARF is mistaken, as was the quoted dicta in SimpleAir. For example, in SpeedTrack, the first suit was filed in November 2006 and ended in a jury verdict in 2012. The second suit was filed in July 2007 (i.e., well before there was a first judgment). And there, we stated “that the Kessler doctrine precludes SpeedTrack’s infringement claims in full.” SpeedTrack, 791 F.3d at 1318 (emphasis added). In other words, this court has indeed relied on the Kessler doctrine to bar assertion of claims against essen- tially the same products made or sold before the judgment of noninfringement in the earlier case. Therefore, WARF’s argument—that Kessler does not apply because A9 and A10 were sold before any final judgment of noninfringe- ment—fails. CONCLUSION We have considered WARF’s remaining arguments and find them unpersuasive. For the foregoing reasons, we af- firm the district court’s denial of WARF’s motion for a new trial in WARF I and affirm the district court’s conclusion that WARF I precludes WARF II. AFFIRMED

18 WARF also cites Brain Life for the same proposi- tion, stating the “Kessler doctrine is ‘temporally limited to acts occurring after final judgment was entered in the first suit.’” Appellant’s Reply Br. 14 (quoting Brain Life, 746 F.3d at 1054). This quote is about claim preclusion—not the Kessler doctrine.