Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca13-14-01431/USCOURTS-ca13-14-01431-0/pdf.json

Parties Involved:
Dow Chemical Company
Cross-Appellant
NOVA Chemicals Corporation (Canada)
Appellant
NOVA Chemicals Inc. (Delaware)
Appellant

Document Text:

United States Court of Appeals 

for the Federal Circuit ______________________ 

THE DOW CHEMICAL COMPANY,

Plaintiff-Cross-Appellant

v.

NOVA CHEMICALS CORPORATION (CANADA), 

NOVA CHEMICALS INC. (DELAWARE),

Defendants-Appellants

______________________ 

2014-1431, 2014-1462

______________________ 

Appeals from the United States District Court for the 

District of Delaware in No. 1:05-cv-00737-LPS, Chief 

Judge Leonard P. Stark.

______________________ 

Decided: August 28, 2015

______________________ 

HARRY J. ROPER, Jenner & Block LLP, Chicago, IL, 

argued for plaintiff-cross-appellant. Also represented by, 

AARON A. BARLOW, PAUL DAVID MARGOLIS; RAYMOND N.

NIMROD, GREGORY D. BONIFIELD, WILLIAM ADAMS, 

CLELAND B. WELTON, II, Quinn Emanuel Urquhart & 

Sullivan, LLP, New York, NY.

DONALD ROBERT DUNNER, Finnegan, Henderson, 

Farabow, Garrett & Dunner, LLP, Washington, DC, 

argued for defendants-appellants. Also represented by 

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MARK J. FELDSTEIN, RONALD BLEEKER, DARREL 

CHRISTOPHER KARL. 

______________________ 

Before PROST, Chief Judge, DYK and WALLACH, Circuit Judges. 

DYK, Circuit Judge. 

The Dow Chemical Company (“Dow”) filed suit 

against NOVA Chemicals Corporation (Canada) and 

NOVA Chemicals Inc. (Delaware) (collectively, “NOVA”), 

alleging infringement of claims of U.S. Patent No. 

5,847,053 (the “’053 patent”) and U.S. Patent No. 

6,111,023 (the “’023 patent”). A jury found the asserted 

claims to be infringed and not invalid. NOVA appealed, 

and we affirmed, holding, inter alia, that the asserted 

claims were not indefinite. Our mandate issued, and 

NOVA’s petition for certiorari was denied by the Supreme 

Court, NOVA Chems. Corp. v. Dow Chem. Co., 133 S. Ct. 

544 (2012). The district court subsequently conducted a

bench trial for the supplemental damages period through 

the expiration date of both patents. The district court 

granted supplemental damages in the form of lost profits 

and reasonable royalties and denied Dow’s request for 

enhanced damages. NOVA appealed, and Dow crossappealed. 

Subsequently, the Supreme Court decided Nautilus, 

Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014), 

altering the standard for indefiniteness. We consider here 

only whether, under Nautilus, the supplemental damages 

award must be reversed because the claims are indefinite. 

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NOVA does not request that we reopen our previous 

judgment as to the infringement trial.1

We hold that the intervening change in the law of indefiniteness resulting from Nautilus provides an exception to the doctrine of law of the case or issue preclusion. 

In our review of the supplemental damages award, we 

therefore evaluate the indefiniteness of the claims under 

the Nautilus standard. In reviewing the supplemental 

damages award under the Nautilus standard, we hold 

that the claims are indefinite and reverse the award of 

supplemental damages. 

BACKGROUND

On October 21, 2005, Dow filed suit against NOVA, 

alleging infringement of claims of the ’053 patent and the 

’023 patent. The asserted claims of both patents cover 

ethylene polymer compositions (a type of plastic) with, 

inter alia, improved modulus, yield strength, impact 

strength, and tear strength. These polymers can be made 

into films that can be down-gauged (made thinner) without losing strength. The claims at issue are independent 

claim 62 and dependent claims 7, 10, and 12 of the ’053 

1 NOVA did attack that judgment in a separate 

case, alleging fraud and fraud on the court. We affirmed 

the district court’s dismissal of NOVA’s complaint. See 

NOVA Chems. Corp. v. Dow Chem. Co., No. 2015-1257, 

2015 WL 3555764 (Fed. Cir. June 9, 2015); Transcript of 

Hearing on Motion to Dismiss at 56, NOVA Chems. Corp. 

v. Dow Chem. Co., No. 13-1601-LPS (D. Del. July 29, 

2014). 2 Claim 6 is representative and provides: 

6. An ethylene polymer composition comprising 

(A) from about 10 percent (by weight of the total 

composition) to about 95 percent (by weight of the 

 

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patent; and independent claim 13 and dependent claims 2, 

5, and 8 of the ’023 patent. Both patents expired on October 15, 2011. 

total composition) of at least one homogeneously 

branched linear ethylene/α-olefin interpolymer 

having:

(i) a density from about 0.89 grams/cubic 

centimeter (g/cm3) to about 0.935 g/cm3, 

(ii) a molecular weight distribution 

(Mw /Mn) from about 1.8 to about 2.8,

(iii) a melt index (I2) from about 0.001 

grams/10 minutes (g/10 min) to about 10 

g/10 min,

(iv) no high density fraction,

(v) a single melting peak as measured using differential scanning calorimetry, and

(vi) a slope of strain hardening coefficient 

greater than or equal to 1.3; and

(B) from about 5 percent (by weight of the total 

composition) to about 90 percent (by weight of the 

total composition) of at least one heterogeneously 

branched linear ethylene polymer having a density from about 0.93 g/cm3 to about 0.965 g/cm3. 

’053 patent col. 16 ll. 4–25.

3 Claim 1 is representative and provides: 

1. An ethylene polymer composition comprising

(A) from about 10 percent (by weight of 

the total composition) to about 95 percent 

 

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Relevant here, claim 6 of the ’053 patent and claim 1 

of the ’023 patent, the independent claims, require “a 

slope of strain hardening coefficient greater than or equal 

to 1.3.” ’053 patent col. 16 ll. 19–20; ’023 patent col. 16 ll. 

29–30. NOVA argues that the patents are indefinite 

because they fail to teach a person having ordinary skill 

in the art how to measure the “slope of strain hardening,” 

(by weight of the total composition) of at 

least one ethylene interpolymer having:

(i) a density from about 0.89 

grams/cubic centimeter (g/cm3) to 

about 0.935 g/cm3, 

(ii) a melt index (I2) from about 

0.001 grams/10 minutes (g/10 

min.) to about 10 g/10 min.,

(iii) a slope of strain hardening coefficient greater than or equal to 

1.3, and

(iv) a Composition Distribution 

Branch Index (CDBI) greater than 

50 percent; and

(B) from about 5 percent (by weight of the 

total composition) to about 90 percent (by 

weight of the total composition) of at least 

one ethylene polymer characterized as 

having a density from about 0.93 g/cm3 to 

about 0.965 g/cm3 and comprising a linear 

polymer fraction, as determined using a 

temperature rising elution fractionation 

(TREF) technique.

’023 patent col. 15 l. 59–col. 16 l. 39. 

 

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which is required to calculate the strain hardening coefficient. 

On June 15, 2010, a jury found that NOVA infringed 

the claims of the asserted patents and that the patents 

were not invalid for indefiniteness. The jury had been 

instructed that “[i]f the meaning of the claims is discernible, it is definite, even though the task may be formidable 

and even if the conclusion may be one over which reasonable persons will disagree.” J.A. 12702. NOVA appealed, 

arguing, inter alia, that the patents were invalid for 

indefiniteness. Dow Chem. Co. v. Nova Chems. Corp., 458 

F. App’x 910, 911, 917–18 (Fed. Cir. 2012). In that previous appeal, on January 24, 2012, we held that the patents 

were not indefinite. Id. at 911, 920. In so holding, we 

applied the law as then established by our pre-Nautilus

precedent, including Exxon Research & Engineering Co. v. 

United States, 265 F.3d 1371 (Fed. Cir. 2001). See Dow, 

458 F. App’x at 917–20.

On remand, the district court, inter alia, held a bench 

trial on supplemental damages for the period between 

January 1, 2010, through October 15, 2011, the date on 

which the patents expired. On March 28, 2014, the district court granted supplemental damages to Dow in the 

form of lost profits and reasonable royalties and denied 

Dow’s request for enhanced damages. Final judgment was 

entered on April 14, 2014. NOVA appealed on April 23, 

2014. Dow cross-appealed on May 1, 2014. 

While the appeals were pending, on June 2, 2014, the 

Supreme Court decided Nautilus. In Nautilus, the Supreme Court held that our standard for indefiniteness 

was contrary to 35 U.S.C § 112, and it announced a new 

standard described in detail below. See 134 S. Ct. at 2124. 

The Court abrogated our previous inquiry into whether 

the claims were “amenable to construction” or “insolubly 

ambiguous,” id., which we applied in cases such as Exxon, 

and relied on in the earlier appeal in this case, Dow, 458 

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F. App’x at 917, 919–20. Under the new standard, “a 

patent is invalid for indefiniteness if its claims, read in 

light of the specification delineating the patent, and the 

prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the 

invention.” Nautilus, 134 S. Ct. at 2124. 

On appeal, NOVA argues that (1) the supplemental 

damages award should be vacated because the patents-insuit are invalid for indefiniteness after the Supreme 

Court’s decision in Nautilus or (2) in the alternative, the 

supplemental damages award was not supported by the 

evidence. In its cross-appeal, Dow contends that the 

district court erred by not awarding enhanced damages

for the supplemental damages period. 

We have jurisdiction pursuant to 28 U.S.C. 

§ 1295(a)(1). 35 U.S.C. § 112 ¶ 2 provides that “[t]he 

specification shall conclude with one or more claims 

particularly pointing out and distinctly claiming the 

subject matter which the applicant regards as his invention.” 35 U.S.C. § 112 (2006). Indefiniteness is a question 

of law that this court reviews de novo. Teva Pharm. USA, 

Inc. v. Sandoz, Inc., 789 F.3d 1335, 1341 (Fed. Cir. 2015). 

We conclude that our prior decision is not binding on 

the issue of indefiniteness because Nautilus changed the 

applicable law, our prior decision rested on the earlier 

law, and the patents-in-suit are invalid for indefiniteness

under the new Nautilus standard. We do not address the 

other issues. We reverse the district court’s award of 

supplemental damages and dismiss the cross-appeal as 

moot. 

DISCUSSION

I 

Dow argues that we are bound by our decision in the 

previous appeal—an appeal from a final judgment under 

Federal Rule of Civil Procedure 54(b)—that the claims 

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were not indefinite. While a judgment entered under Rule 

54(b) is a final judgment, that final judgment cannot have

any greater effect than any other final judgment. The 

earlier appeal was from the entry of judgment in the jury 

verdict (for the period March 2002–December 31, 2009)

while the current appeal is from the supplemental damages judgment (for the period January 1, 2010–October 

15, 2011). An award of supplemental damages is designed 

to compensate the patentee “for periods of infringement 

not considered by the jury,” Whitserve, LLC v. Comput. 

Packages, Inc., 694 F.3d 10, 38 (Fed. Cir. 2012) (emphasis 

added), and necessarily implicates patent validity. In 

order to prevail on a claim for supplemental damages, a 

patentee must establish infringement for the supplemental damages period. If “an act that would have been 

an infringement or an inducement to infringe pertains to 

a patent that is shown to be invalid, there is no patent to 

be infringed.” Commil USA, LLC v. Cisco Sys., Inc., 135 S. 

Ct. 1920, 1929 (2015). 

The doctrine of claim preclusion does not apply as between the claims for the first and second damages periods. It is well-established that, as to claims for continuing 

conduct after the complaint is filed, each period constitutes a separate claim.4 See 18 Charles Alan Wright, 

4 Likewise, claims that have accrued at the time of 

the complaint generally must be brought together, and 

the plaintiff need not supplement the complaint to cover 

continuing conduct. 18 Charles Alan Wright, Arthur R. 

Miller & Edward H. Cooper, Federal Practice and Procedure § 4409 (2d ed. 2002) (“Most cases rule that an action 

need include only the portions of the claim due at the time 

of commencing that action, frequently observing that the 

opportunity to file a supplemental complaint is not an 

obligation.”); see also, e.g., Gillig v. Nike, Inc., 602 F.3d 

 

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Arthur R. Miller & Edward H. Cooper, Federal Practice 

and Procedure § 4409 (2d ed. 2002) (“A substantially 

single course of activity may continue through the life of a 

first suit and beyond. The basic claim-preclusion result is 

clear: a new claim or cause of action is created as the 

conduct continues.”); Crowe v. Leeke, 550 F.2d 184, 187 

(4th Cir. 1977) (“We glean from the[] cases that res judicata [claim preclusion] has very little applicability to a 

fact situation involving a continuing series of acts, for 

generally each act gives rise to a new cause of action.”); 

Exhibitors Poster Exchange, Inc. v. Nat’l Screen Serv. 

Corp, 421 F.2d 1313, 1316, 1318–19 (5th Cir. 1970) (res 

judicata [claim preclusion] does not apply where plaintiff

alleges “same facts—[a] 1961 refusal to deal [as an antitrust violation]”—but sought in a second and third suit to 

recover damages suffered since losing on summary judgment in the first suit since the damages arose from “non 

actions” subsequently occurring). 

This rule applies to patent infringement claims. As we 

explained just last year, 

traditional notions of claim preclusion do not apply when a patentee accuses new acts of infringement, i.e., post-final judgment, in a second suit—

1354, 1363 (Fed. Cir. 2010) (res judicata [claim preclusion] does not apply where claims accrue during action 

and are not the subject of the first judgment because “the 

doctrine of res judicata does not punish a plaintiff for 

exercising the option not to supplement the pleadings 

with an after-acquired claim” (citations omitted)); Spiegel 

v. Cont’l Ill. Nat’l Bank, 790 F.2d 638, 646 (7th Cir. 1986) 

(claim preclusion barred suit except for claims related to 

two new acts which “occurred after the filing” of the 

earlier suit).

 

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even where the products are the same in both 

suits. Such claims are barred under general preclusion principles only to the extent they can be 

barred by issue preclusion, with its attendant limitations. 

Brain Life, LLC v Elekta Inc., 746 F.3d 1045, 1056 (Fed. 

Cir. 2014); see Aspex Eyewear, Inc. v. Marchon Eyewear, 

Inc., 672 F.3d 1335, 1342–44 (Fed. Cir. 2012); see also,

e.g., SynQor, Inc. v. Artesyn Techs., Inc., 709 F.3d 1365, 

1385–86 (considering whether intent element of induced 

infringement had been shown in the supplemental damages period). 

Here, the bulk of the supplemental damages accrued 

after the Rule 54(b) judgment, and it is clear that claim 

preclusion also does not apply to damages accruing after 

the filing of the complaint and not the subject of the first 

judgment. See note 4, supra. All supplemental damages 

here accrued after the filing of the complaint.

While claim preclusion does not apply, ordinarily issue preclusion (or law of the case) would bar relitigation

in the supplemental damages period of issues (such as 

validity) that were resolved as to the earlier time periods. 

18 Charles Alan Wright, Arthur R. Miller & Edward H. 

Cooper, Federal Practice and Procedure § 4409 (2d ed. 

2002 (“[Although] claim preclusion often cannot apply in 

settings of continuing . . . conduct, . . . it may be proper to 

conclude that the issues precluded by the first litigation 

embrace [issues in the second] . . . .”). That would be the 

case whether the supplemental damages proceeding were 

viewed as a continuation of the ongoing case or as a new 

proceeding.5 In the former event, the doctrine of law of 

5 Because Dow does not seek to reopen the infringement trial judgment, Dow’s arguments that we lack 

 

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the case would preclude relititgation. In the latter event 

(treating the supplemental damages proceeding as a new 

proceeding) issue preclusion would bar relitigation. “[T]he 

doctrine [of law of the case] posits that when a court 

decides upon a rule of law, that decision should continue 

to govern the same issues in subsequent stages in the 

same case.” Christianson v. Colt Indus. Operating Corp., 

486 U.S. 800, 815–16 (1988) (quoting Arizona v. California, 460 U.S. 605, 618 (1983)) (emphasis added) (alterations in original). Issue preclusion “bars ‘successive 

litigation of an issue of fact or law already litigated and 

resolved in a valid court determination essential to the 

prior judgment.’” Taylor v. Sturgell, 553 U.S. 880, 892 

(2008) (quoting New Hampshire v. Maine, 532 U.S. 742, 

748–49 (2001)) (emphasis added).6 But both doctrines are 

jurisdiction on the indefiniteness issue are without merit. 

The cases that Dow cites relate to situations where a 

party sought to reopen a previous judgment. See Brown v. 

Eli Lilly & Co., 654 F.3d 347, 354–55 (2d Cir. 2011) 

(holding that court was without jurisdiction to consider 

appeal as to two parties because the judgment against one 

party was appealed but the appeal was dismissed as 

untimely and the judgment against the other party was 

not appealed); In re Martin, 400 F.3d 836, 841 & n.1 (10th 

Cir. 2005) (appeal limited to later order because earlier 

order was a final judgment and that judgment was not 

appealed); Crowder v. Telemedia, Inc., 659 F.2d 787, 787–

88 (7th Cir. 1981) (per curiam) (holding that court lacked 

jurisdiction over previous judgment that had become final 

and had not been timely appealed). 

6 While we apply the law of the regional circuit to 

general procedural questions, we apply this court’s precedent to questions implicating substantive issues of patent 

law or issues implicating the scope of our own previous 

decisions. See Soverain Software LLC v. Victoria’s Secret 

 

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subject to an exception—when governing law is changed 

by a later authoritative decision. See 18B Charles Alan 

Wright, Arthur R. Miller & Edward H. Cooper, Federal 

Practice and Procedure § 4478 (2d ed. 2002) (law of the 

case); 18 Charles Alan Wright, Arthur R. Miller & Edward H. Cooper, Federal Practice and Procedure § 4425 

(2d ed. 2002) (issue preclusion). 

With respect to law of the case, “[p]erhaps the most 

obvious justifications for departing . . . arise when there 

has been an intervening change of law outside the confines of the particular case.” 18B Charles Alan Wright, 

Arthur R. Miller & Edward H. Cooper, Federal Practice 

and Procedure § 4478; see Rose Acre Farms, Inc. v. United 

States, 559 F.3d 1260, 1277–78 (Fed. Cir. 2009) (holding 

that intervening Supreme Court decision issued after 

prior appeal rendered prior decision “obsolete,” “[g]iven 

the significant change in the law”); Wopsock v. Natchees, 

454 F.3d 1327, 1333 (Fed. Cir. 2006) (finding that law of 

the case did not apply because “this is a case in which 

there has been a change in the law”). The exception 

applies even if the issue was resolved on appeal in an 

earlier stage of the proceeding. Indeed, the premise of the 

exception in the appellate context is that there was such 

an earlier resolution. See Litton Sys., Inc. v. Honeywell

Inc., 238 F.3d 1376, 1379–81 (Fed. Cir. 2001) (revisiting 

prior holding on prosecution history estoppel because 

intervening en banc authority adopted a contrary approach, noting “[w]e are aware of no decision of this court 

that has applied the law of the case in the face of a relevant change in controlling legal authority”); Mendenhall 

v. Barber-Greene Co., 26 F.3d 1573, 1576, 1580, 1583

Direct Brand Mgmt., LLC, 778 F.3d 1311, 1314 (Fed. Cir. 

2015). We therefore apply our own law where, as here, we 

are interpreting our own prior decision. 

 

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(Fed. Cir. 1994) (holding that an exception to law of the 

case applied and the asserted claims were invalid, revisiting a previous final decision that the claims were not 

invalid); see also United States v. Plugh, 648 F.3d 118, 

121–24 (2d Cir. 2011) (revisiting holding on first appeal 

due to intervening Supreme Court precedent); Spiegla v. 

Hull, 481 F.3d 961, 963–67 (7th Cir. 2007) (holding that 

“because the judgment in this case is not yet final, we are 

obliged to reevaluate” a previous appellate holding under 

intervening Supreme Court precedent); United States v. 

Windom, 82 F.3d 742, 746, 748–49 (7th Cir. 1996), vacated on other grounds, 103 F.3d 523 (7th Cir. 1996) (holding 

that defendant was “not foreclosed from re-raising” merits 

of conviction previously affirmed where an intervening 

Supreme Court decision was issued after remand for 

sentencing); United States v. Garcia, 77 F.3d 274, 276–77 

(9th Cir. 1996) (reconsidering affirmance of conviction sua 

sponte in light of intervening authority after an earlier 

remand “for the limited purpose of reimposing the mandatory” sentence). But the exception of course does not apply 

if the proceeding has reached the stage of final judgment. 

See Mendenhall, 26 F.3d at 1582 (Fed. Cir. 1994). Here, 

the supplemental damages proceeding had not been 

concluded at the time of Nautilus. 

Similarly, issue preclusion does not apply where “a 

new determination is warranted in order to take account 

of an intervening change in the applicable legal context or 

otherwise to avoid inequitable administration of the 

laws.” Restatement (Second) of Judgments § 28(2) (1982). 

Therefore, a court is not bound by a previous decision 

where there is a change in the controlling precedent. 18 

Charles Alan Wright, Arthur R. Miller & Edward H. 

Cooper, Federal Practice and Procedure § 4425 (“Preclusion is most readily defeated by specific Supreme Court 

overruling of precedent relied upon in reaching the first 

decision.”); see Bobby v. Bies, 556 U.S. 825, 836 (2009) 

(“[E]ven if the core requirements for issue preclusion had 

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been met, an exception to the doctrine’s application would

be warranted due to this Court’s intervening decision . . . .”); Bingaman v. Dep’t of Treasury, 127 F.3d 1431, 

1438 (Fed. Cir. 1997) (“In a number of cases, this court 

and others have held that a significant change in the 

‘legal atmosphere’—whether in the form of new legislation, a new court decision, or even a new administrative 

ruling—can justify a later court’s refusal to give collateral 

estoppel effect to an earlier decision.”); Wilson v. Turnage, 

791 F.2d 151, 156–57 (Fed. Cir. 1986) (holding that issue 

preclusion did not apply where Federal Circuit decision 

was “such an intervening change in the legal atmosphere 

that it renders the bar of collateral estoppel inapplicable 

in this case”); see also Comm’r of Internal Revenue v. 

Sunnen, 333 U.S. 591, 600 (1948) (“[A] supervening 

decision cannot justly be ignored by blind reliance upon 

the rule of collateral estoppel”).

The change in law exception applies whether the 

change in law occurs while the case is before the district 

court or while the case is on appeal. See Spiegla, 481 F.3d 

at 964 (7th Cir. 2007) (holding that defendants had not 

waived challenge to holding in first appeal where issue 

not raised on remand in district court or initial briefing 

because intervening decision was issued after appellate 

briefing); Mendenhall, 26 F.3d at 1583 (law of the case did 

not apply where new decision issued while case on appeal); Morris v. Am. Nat’l Can Corp., 988 F.2d 50, 51–53 

(8th Cir. 1993) (law of the case did not apply where, after 

first appeal and decision on remand by district court, 

Supreme Court case changed prevailing law); Wilson, 791 

F.2d at 154, 157 (exception to issue preclusion applied 

where intervening decision issued while case pending 

before this court). 

Three conditions must be satisfied to reopen a previous decision under the change of law exception for both 

law of the case and issue preclusion. First, the governing 

law must have been altered. See 18 Charles Alan Wright, 

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Arthur R. Miller & Edward H. Cooper, Federal Practice 

and Procedure § 4425 (2d ed. 2002) (exception to issue 

preclusion only available as a result of “independent 

changes” in the law and not “merely because the defeated 

party wishes to reargue the law”); 18B Charles Alan 

Wright, Arthur R. Miller & Edward H. Cooper, Federal 

Practice and Procedure § 4478 (2d ed. 2002) (“The easiest 

cases [for departing from law of the case] occur when the 

law has been changed by a body with greater authority on 

the issue . . . .”).

Second, the decision sought to be reopened must have 

applied the old law. See, e.g., Litton, 238 F.3d at 1380

(holding that intervening law exception to law of the case 

applied where previous opinion had followed approach 

expressly repudiated by intervening en banc decision); 

Rose Acre Farms, 559 F.3d at 1278 (intervening law 

exception applied where prior opinion had “clearly applied 

the [old] test”). 

Third, the change in law must compel a different result under the facts of the particular case. See Hughes 

Aircraft Co. v. United States, 140 F.3d 1470, 1475 (Fed. 

Cir. 1998), overruled on other grounds by Festo Corp. v. 

Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558 

(Fed. Cir. 2000) (rejecting argument that issue should be 

reopened because the “analysis performed in [the previous 

appeal] satisfies the . . . rule as stated in [an intervening 

Supreme Court decision]”); Hughes Aircraft Co. v. United 

States, 86 F.3d 1566, 1576 (Fed. Cir. 1996), cert. granted, 

judgment vacated on other grounds, 520 U.S. 1183 (1997) 

(holding that intervening law exception to law of the case 

did not apply where “analysis in the court’s prior decision 

is . . . entirely consistent” with intervening en banc decisions); Cal. Fed. Bank v. United States, 395 F.3d 1263, 

1274–75 (Fed. Cir. 2005) (holding that intervening en 

banc decision did not warrant reopening previous decision 

because principles of en banc decision did not apply on the 

facts of the case on appeal). Here, as the Supreme Court 

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recognized in Nautilus, the Supreme Court’s new standard does not always lead to a different result. 134 S. Ct. at 

2130–31 (remanding for consideration of whether claims 

were definite under the new standard).

Each of these requirements was satisfied here. 

First, there can be no serious question that Nautilus

changed the law of indefiniteness. This was indeed the 

very purpose of the Nautilus decision. Prior to Nautilus, 

we applied the following test: 

[W]hat we have asked is that the claims be amenable to construction, however difficult that task 

may be. If a claim is insolubly ambiguous, and no 

narrowing construction can properly be adopted, 

we have held the claim indefinite. If the meaning 

of the claim is discernible, even though the task 

may be formidable and the conclusion may be one 

over which reasonable persons will disagree, we 

have held the claim sufficiently clear to avoid invalidity on indefiniteness grounds.

Exxon, 265 F.3d at 1375. In Nautilus, the Supreme Court 

expressly rejected that “insolubly ambiguous” or “amenable to construction” standard. Nautilus, 134 S. Ct. at 

2124. Rather, the Court “h[e]ld that a patent is invalid for 

indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, 

fail to inform, with reasonable certainty, those skilled in 

the art about the scope of the invention.” Id. The Court 

explained further: “[i]t cannot be sufficient that a court 

can ascribe some meaning to a patent’s claim; the definiteness inquiry trains on the understanding of a skilled 

artisan at the time of the patent application, not that of a 

court viewing matters post hoc.” Id. at 2130. 

Nautilus emphasizes “the definiteness requirement’s 

public-notice function.” 134 S. Ct. at 2130; see also id. at 

2129 (“[A] patent must be precise enough to afford clear 

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notice of what is claimed, thereby ‘appris[ing] the public 

of what is still open to them’” (quoting Markman v. 

Westview Instruments, Inc., 517 U.S. 370, 373 (1996)) 

(alterations in original)). Although the Court recognized 

that “[s]ome modicum of uncertainty” may be tolerated, 

id. at 2128, the patent and prosecution history must 

disclose a single known approach or establish that, where 

multiple known approaches exist, a person having ordinary skill in the art would know which approach to select. 

See Teva, 789 F.3d at 1341, 1344–45 (holding claim indefinite where molecular weight could be measured three 

different ways and would yield different results and the 

patent and prosecution history did not provide guidance 

as to which measure to use). Particularly this is so where 

different approaches to measurement are involved. See id.

at 1341, 1344–45. Thus, contrary to our earlier approach,

under Nautilus, “[t]he claims, when read in light of the 

specification and the prosecution history, must provide 

objective boundaries for those of skill in the art.” Interval 

Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1371 (Fed. 

Cir. 2014) (citing Nautilus, 134 S. Ct. at 2130 & n.8). 

Second, there is also no question that our original decision applied pre-Nautilus law. Dow argues that our 

opinion in the previous appeal was not inconsistent with 

Nautilus and that we did not apply the “amenable to 

construction” or “insolubly ambiguous standard.” But the 

fact that we did not include that particular language does 

not mean that we were not applying the prevailing legal 

standard. We cited Exxon, see Dow, 458 F. App’x at 917,

which Nautilus specifically cited as exemplary of the 

rejected Federal Circuit standard. See Nautilus, 134 S. Ct. 

at 2130 n.9. Applying Exxon, we explained that a patent

is definite under § 112 ¶ 2 if:

“one skilled in the art would understand the 

bounds of the claim when read in light of the specification.” A claim is not indefinite merely because 

it is difficult to construe. To be indefinite, a claim 

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term must be such that “no narrowing construction can properly be adopted” to interpret the 

claim.

Dow, 458 F. App’x at 917 (quoting Exxon, 265 F.3d at 

1375). We also explained that “the test for indefiniteness 

is not whether the scope of the patent claims is easy to 

determine, but whether ‘the meaning of the claim is 

discernible, even though the task may be formidable and 

the conclusion may be one over which reasonable persons 

will disagree.’” Id. at 920 (quoting Exxon, 265 F.3d at 

1375). This language corresponds exactly to the “amenable to construction” or “insolubly ambiguous” standard 

rejected in Nautilus. 

Third, as we now discuss, our original decision would 

have been different under the new Nautilus standard. 

II

The claim term at issue here provides for “a slope of 

strain hardening coefficient greater than or equal to 1.3.” 

’053 patent col. 16 ll. 19–20; ’023 patent col. 16 ll. 29–30. 

The patents provide that the “slope of strain hardening 

coefficient” (“SHC”) is calculated according to the following equation: 

SHC = (slope of strain hardening)*(I2)0.25

where I2=melt index in grams/10 minutes. ’053 patent col. 

6 ll. 45–50; ’023 patent col. 7 ll. 22–28. “The SHC coefficient is a new Dow construct, not previously known in the 

art . . . .” Dow, 458 F. App’x at 918. 

Strain hardening is a property wherein a material becomes harder as it is stretched. The ’053 and ’023 patents 

teach that tensile properties, including strain hardening, 

may be tested using a device called the Instron Tensile 

Tester. The Instron Tensile Tester subjects a sample to an 

increasing load, stretching it until it breaks. The machine 

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measures the force, or load, applied to the sample and the 

length that the sample stretches. 

The measurements taken by the Instron Tensile Tester are then plotted on a graph. The resulting curve is 

called the “tensile curve” or “stress/strain curve.” On the 

stress/strain curve, the force (or load) applied to the 

sample is plotted on the y-axis, and the resulting elongation (or displacement) of the sample is plotted on the xaxis. The behavior of the material claimed by the patent 

changes as it is stretched, and those changes are shown 

on the stress/strain curve. A figure from the prior art

utilized in Dow’s brief illustrates a typical stress/strain 

curve. 

Appellee’s Br. 7; J.A. 10493.

There are three main phases of behavior, corresponding to regions I, III, and IV on the figure. At first, when 

an increasing force is applied to a sample of the compound 

claimed by the patent, the sample pulls its initial load

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and has little or no elongation. In other words, when an 

increasing force is initially applied, the sample stretches 

very little, if at all. This is shown in region I in the figure 

above. Then, after the sample has been subjected to the 

initial load, it stretches a relatively large amount in 

response to little or no increase in force. The portion of the 

stress/strain curve showing these latter effects is called 

the “drawing region.” The drawing region has a lower, or 

relatively flat, slope because the force increases little (or 

not at all), while the elongation increases significantly. 

The drawing stage is shown as region III in the figure 

above.7

After the drawing stage, there is a third phase—the 

strain hardening region—which corresponds to region IV 

in the figure above. The strain hardening region is the 

focus of the claim term at issue here. In the strain hardening region, the material hardens, and it stretches much 

less in response to an increased force than in the drawing 

region. At first, in the strain hardening region, there is 

still some drawing effect. As the material continues to 

stretch, the strain hardening effect increases and the 

drawing effect decreases. When plotted, the strain hardening region is curved in most instances. Because the 

strain hardening region is typically curved, it does not 

have a single slope. Typically, the curve will get steeper 

as more force is applied. 

NOVA argues that the term “slope of strain hardening 

coefficient,” ’053 patent col. 16 l. 19, is indefinite because 

the patent fails to teach with reasonable certainty where 

7 Region II in the figure corresponds to a region 

where the force decreases and is not relevant here. 

 

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and how the “slope of strain hardening” should be measured. 8

Although the patents state that “FIG. 1 shows the 

various stages of the stress/strain curve used to calculate 

the slope of strain hardening,” ’053 patent col. 6 ll. 40–41; 

’023 patent col. 7 ll. 18–19, the patents do not contain the

FIG. 1 referenced in those passages. Nor do the patents 

include any other figure showing the stress/strain curve. 

The specification of the ’053 and ’023 patents teach that 

“[t]he slope of strain hardening is calculated from the 

resulting tensile curve by drawing a line parallel to the 

strain hardening region of the . . . stress/strain curve.” 

’053 patent col. 6 ll. 27–29; ’023 patent col. 7 ll. 5–7. 

At trial, Dow’s expert Dr. Hsiao testified that “one of 

ordinary skill in the art would know that the slope of the 

hardening curve would have to be measured at its maximum value, which reflects the best tensile performance of 

the material.” Dow, 458 F. App’x at 919. We may assume 

that, as Dr. Hsiao testified and as Dow repeatedly argues, 

it was known that the maximum slope should be measured. 

But three methods existed to determine the maximum 

slope, each providing, as Dow admits, “simply a different 

way of determining the maximum slope.” Appellee’s Br. 45 

(emphasis added). Dow admitted that those three methods “all typically occur at the same place—at the end of 

the curve where the maximum slope is located.” Id. We 

refer to these methods as the “10% secant tangent method,” “final slope method,” and “most linear method.” 

8 NOVA also argues that the claim is indefinite because it failed to identify the units for the slope of strain 

hardening. In light of our disposition we need not reach 

this issue. 

 

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The 10% secant tangent method is taught by a later 

Dow patent, U.S. Patent No. 6,723,398 (the “’398 patent”). 

Under the 10% secant tangent method, “[t]he slope of 

strain hardening is conveniently taken as the line representing a 10 percent secant tangent which is calculated 

from the failure point to the point at 10 percent extension 

before the failure point (where 10 percent extension 

before is equal to 90 percent of the total extension or 

strain).” ’398 patent col. 11 ll. 6–11. In other words, a line 

is drawn between two points, one at the failure point and 

one at 10% before the failure point. The slope of that line 

is then calculated. See id. FIG. 2. In the final slope method, the “slope of strain hardening [is] calculated from the 

slope of [a] tensile curve just prior to break.” J.A. 6662. In 

the most linear method, “[t]he slope of the strain hardening region (SSH) was measured by manually selecting two 

points in the most linear part of the [strain hardening] 

region” and dividing the change in force by the change in 

elongation. J.A. 6704. The constant slope region closely 

precedes the breaking point. 

For purposes of this case, Dr. Hsiao developed yet another method—of his own invention—to calculate the 

slope of strain hardening. Dr. Hsiao’s testing produced 

curves with 1,500 data points representing the force 

applied to a sample and the sample’s elongation. He then 

analyzed subsets of fifty data points. For each set of fifty 

data points, Dr. Hsiao used a computer to apply a linear 

regression routine to fit a line to the fifty points and 

calculate a slope of the resulting line. He then selected the 

highest of those resulting slopes in order to find the 

maximum slope. 

There is no question that each of these four methods 

may produce different results, i.e., a different slope. Dr. 

Hsiao testified that the 10% secant tangent method, the 

final slope method, the most linear method, and the 

method he invented could produce different results. In 

comparison to the three other methods, Dr. Hsiao’s methCase: 14-1431 Document: 63-2 Page: 22 Filed: 08/28/2015
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od would produce a higher value. Because the methods do 

not always produce the same results, the method chosen 

for calculating the slope of strain hardening could affect 

whether or not a given product infringes the claims. 

Neither the patent claims nor the specification here 

discusses the four methods or provides any guidance as to 

which method should be used or even whether the possible universe of methods is limited to these four methods. 

Nor does either party argue that the prosecution history 

provides any guidance. Further, Dr. Hsiao did not testify 

that one of ordinary skill in the art would choose his 

method over the three known methods. Indeed, he was 

not even aware of the other methods at the time he did 

his analysis. He admitted that he applied only his judgment of what a person of ordinary skill would believe and 

did not interview anyone or cite any references discussing 

how a person at the time of the patent application would 

have calculated the slope of strain hardening. 

The question is whether the existence of multiple 

methods leading to different results without guidance in 

the patent or the prosecution history as to which method 

should be used renders the claims indefinite. Before 

Nautilus, a claim was not indefinite if someone skilled in 

the art could arrive at a method and practice that method. 

Exxon, 265 F.3d at 1379. In our previous opinion, relying 

on this standard, we held that the claims were not indefinite, holding that “the mere fact that the slope may be 

measured in more than one way does not make the claims 

of the patent invalid.” Dow, 458 F. App’x at 920. This was 

so because Dow’s expert Dr. Hsiao, a person skilled in the 

art, had developed a method for measuring maximum 

slope. See id. at 919–20.

Under Nautilus this is no longer sufficient. “[A] patent is invalid for indefiniteness if its claims, read in light 

of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, 

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those skilled in the art about the scope of the invention.” 

134 S. Ct. at 2124; see also id. at 2129 (“[W]e read § 112, 

¶ 2 to require that a patent’s claims, viewed in light of the 

specification and prosecution history, inform those skilled 

in the art about the scope of the invention with reasonable certainty.”). Here the required guidance is not provided by the claims, specification, and prosecution history. 

In this respect this case is quite similar to our recent 

decision in Teva, decided under the Nautilus standard. In 

Teva,9 the claim limitation at issue recited the term 

“molecular weight.” 789 F.3d at 1338. But there were

three relevant measures for molecular weight—peak 

average molecular weight (“Mp”), number average molecular weight (“Mn”), and weight average molecular weight 

(“Mw”)—where each was calculated in a different manner 

and each typically had a different value. Id. We looked to 

“the patent record—the claims, specification, and prosecution history—to ascertain if they convey to one of skill in 

the art with reasonable certainty the scope of the invention claimed.” Id. at 1341. Neither the claims nor the 

specification contained an explicit definition of molecular 

weight, id., and the prosecution history contained inconsistent statements, id. at 1342–1344. Therefore, the 

claims were indefinite under Nautilus. Id. at 1344–45. 

This was so even though the patentee’s expert—like Dr. 

Hsiao here—testified that someone skilled in the art could 

determine which method was the most appropriate. Id. at 

1338, 1341. 

9 This case was on remand from the Supreme 

Court, where the Court held that subsidiary factual 

findings made by a district court in claim construction are 

reviewed for clear error. Teva Pharm. USA, Inc. v. 

Sandoz, Inc., 135 S. Ct. 831, 841 (2015).

 

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The claims here are even more clearly indefinite than 

those in Teva. Here, Dr. Hsiao’s chosen method was not 

even an established method but rather one developed for 

this particular case. As we held in Interval Licensing, a 

claim term is indefinite if it “leave[s] the skilled artisan to 

consult the ‘unpredictable vagaries of any one person’s 

opinion.’” 766 F.3d at 1374 (quoting Datamize, LLC v. 

Plumtree Software, Inc., 417 F.3d 1342, 1350 (Fed. Cir. 

2005)).10 The claims here are invalid as indefinite, and the 

award of supplemental damages must be reversed. Under 

these circumstances, we need not address the crossappeal as to enhanced damages.

APPEAL NO. 2014-1431 REVERSED

APPEAL NO. 2014-1462 DISMISSED AS MOOT

COSTS 

Costs to NOVA. 

10 This case is unlike Biosig Instruments, Inc. v. 

Nautilus, Inc., 783 F.3d 1374, 1377 (Fed. Cir. 2015). In 

Biosig, we held that the prosecution history, the language 

of the claims, and the knowledge of one skilled in the art 

demonstrated that “a skilled artisan would understand 

the inherent parameters of the invention as provided in 

the intrinsic evidence” and that the claim term at issue 

“informs a skilled artisan with reasonable certainty of the 

scope of the claim.” Id. at 1382–84. 

 

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