
United States Court of Appeals for the Federal Circuit

                                           99-1584, 00-1005


                                    INSITUFORM TECHNOLOGIES, INC.,
                                    INSITUFORM (Netherlands) B.V.,
                                   and INSITUFORM GULF SOUTH, INC.,

                                                   Plaintiffs-Cross Appellants,

                                                  v.

                                        CAT CONTRACTING, INC.,
                             FIRSTLINER U.S.A., INC., and GUILIO CATALLO,

                                                   Defendants-Appellants,

                                                 and

                                 MICHIGAN SEWER CONSTRUCTION COMPANY,

                                                   Defendant-Appellant,

                                                 and

                             KANAL SANIERUNG HANS MUELLER GmbH & CO. KG,

                                                   Defendant-Appellee.


      Harold James, Epstein Drangel Bazerman & James LLP, of New York, New York, for plaintiffs-
cross appellants.

      Arnold Anderson Vickery, of Houston, Texas, for CAT Contracting, Inc., et al.

      N. Elton Dry, Dry & Tassin, LLP, of Houston, Texas, for defendant-appellant Michigan Sewer
Construction Company.

      Richard L. Stanley, Howrey Simon Arnold & White, LLP, of Houston, Texas, for defendant-
appellee Kanal Sanierung Hans Mueller GmbH & Co., KG.  With him on the brief was Albert B. Deaver,
Jr.

On remand from the Supreme Court of the United States


                        United States Court of Appeals for the Federal Circuit




                                           99-1584, 00-1005

                                    INSITUFORM TECHNOLOGIES, INC.,
                                    INSITUFORM (NETHERLANDS) B.V.,
                                   and INSITUFORM GULF SOUTH, INC.,

                                     Plaintiffs-Cross Appellants,

                                                  v.

                                        CAT CONTRACTING, INC.,
                             FIRSTLINER U.S.A., INC., and GIULIO CATALLO,

                                             Defendants-Appellants,


                                  and


                                 MICHIGAN SEWER CONSTRUCTION COMPANY,

                                                          Defendant-Appellant,

                                                 and

                             KANAL SANIERUNG HANS MUELLER GmbH & CO. KG,

                                             Defendant-Appellee.


                       __________________________

                       DECIDED:  October 4, 2004
                       __________________________

Before MAYER, Chief Judge, MICHEL, and SCHALL, Circuit Judges.

SCHALL, Circuit Judge.

      Defendants Cat Contracting,  Inc.  (“CAT”),  Firstliner  U.S.A.,  Inc.  (“Firstliner”),  Giulio
Catallo (sometimes referred to  as  “Catallo”),  and  Michigan  Sewer  Construction  Company  (“MSC”)
(“defendants”) appeal the judgment of the United States District Court for the Southern  District  of
Texas holding them liable for infringement of United States Patent No. 4,366,012 (“the ‘012  patent”)
and  awarding  plaintiffs  Insituform  Technologies,  Inc.  (“Insituform  Technologies”),  Insituform
(Netherlands) B.V. (“Insituform Netherlands”), and Insituform Gulf South,  Inc.  (“Insituform  Gulf”)
(“plaintiffs”) damages for that infringement.  Insituform Techs., Inc. v. Cat Contracting, Inc.,  No.
H-90-1690, slip op. (S.D. Tex. Aug. 31, 1999) (“District Court  Opinion”).   Defendants  also  appeal
the joinder of Insituform Netherlands as a plaintiff.  Id. at 21-22.  In addition,  CAT,  Firstliner,
and Catallo appeal the district court’s joinder of Catallo as a defendant.  Insituform  Techs.,  Inc.
v. Cat Contracting, Inc., No. H-90-1690, slip op. at 9 (Aug. 30, 1999) (“Joinder Order”).  For  their
part, plaintiffs cross-appeal the ruling of the district court  declining  to  hold  defendant  Kanal
Sanierung Hans Mueller GmbH & Co. KG (“KS”) vicariously  liable  to  plaintiffs  under  an  alter-ego
theory of induced infringement.  District Court Opinion, slip op. at 44-45.
      We affirm the judgment of infringement with respect to all  defendants.   We  also  affirm  the
district court’s joinder of Insituform Netherlands as a plaintiff, its joinder of Giulio  Catallo  as
a defendant, and its ruling declining  to  hold  KS  vicariously  liable  for  induced  infringement.
However, we vacate the judgment that the infringement of CAT and Firstliner was  willful  and  remand
for further proceedings on the issue of willful infringement.  We also vacate  the  district  court’s
damages award and remand for further proceedings  to  determine  damages  based  on  when  defendants
ceased selling the pipe repair process that was found to infringe the ‘012 patent.   Accordingly,  we
affirm-in-part, vacate-in-part, and remand.
                                              BACKGROUND
                                                  I.
      Underground pipes, such as sewer pipes, are often subject to great stress.  As a  result,  over
time, the pipes develop cracks and other structural defects, which can result  in  leakage.   In  the
past, the only way to rehabilitate a section of underground pipe was to dig  up  the  broken  section
and replace it.  Eric Wood, the sole inventor named on the  ‘012  patent,  pioneered  a  process  for
rehabilitating underground pipe without digging it up.
      The ‘012 patent discloses Wood’s invention.  The patent relates to a method for performing pipe
repair without removing the damaged pipe from the ground.  The method  involves  installing  a  liner
into the pipe.  Claim 1 of the patent, the only claim at issue, claims a process for  impregnating  a
flexible tube liner with resin prior to insertion of the liner into a damaged pipe.   The  liner  has
an impermeable film on the outside and a resin-absorbent, felt layer on  the  inside.   A  vacuum  is
applied to the inside of the liner by cutting a window into the outer, impermeable film,  applying  a
cup (a “vacuum cup”) to the outside of the window, and connecting the other  end  of  the  cup  to  a
vacuum source.  Using the created vacuum, a section of the inside of the liner  is  impregnated  with
resin, which is drawn through the liner.  The vacuum cup is then moved  to  another  section  of  the
liner while the previously used window is sealed.  This  process  for  impregnating  the  liner  with
resin allows for impregnation at the jobsite, eliminating the need to transport  a  heavier,  already
impregnated liner to the site.
                                                 II.
      This case has a lengthy procedural history.  The issues before us arise from a  complex  series
of trials, appeals, and cross-appeals that now span nearly fourteen years.  We  briefly  review  each
significant decision in turn.
A. Plaintiffs’ suit for patent infringement
      The original defendants in this action were CAT, Inliner U.S.A., Inc. (“Inliner”), MSC, and KS.
 Inliner subsequently changed its name to Firstliner U.S.A., Inc., and we refer to this defendant  as
Firstliner throughout.  Firstliner and CAT are in the business of  rehabilitating  and  restructuring
various types of pipes, including sanitary, storm sewer, water main, conduit,  and  industrial  pipe.
District Court Opinion, slip  op.  at  5.   Firstliner  oversees  the  marketing  of  its  trenchless
procedure for pipe rehabilitation to potential licensees.  Id.  In addition, Firstliner  manufactures
pipeliners and related materials, which it sells to CAT and its licensees.  Id.  CAT  is  responsible
for marketing, bidding for, and negotiating  contracts  with  customers  and  managing  its  pipeline
rehabilitation contracts.  Id.  Giulio Catallo, who was subsequently added as  a  defendant,  is  the
individual principal of both CAT and Firstliner.  MSC is also in the  pipe  rehabilitation  business.
CAT was involved in a joint venture with MSC for performing the accused processes.
      KS is a German sewer rehabilitation company owned by Hans Mueller.  After  reading  about  KS’s
proprietary sewer rehabilitation technology in a trade  magazine,  Giulio  Catallo  contacted  KS  to
obtain a license for that technology.  Id.  Catallo subsequently  acquired  the  rights  to  use  the
accused processes from Kanal Mueller Gruppe International GmbH &  Co.  (“Gruppe”),  a  German  export
licensing company also owned by Hans Mueller.  Although KS stated in a  letter  written  on  November
10, 1989, that CAT was a “qualified Licensee for  our  KM-INLINER  sewer  relining  process  for  the
territories of the USA,” there was no formal license agreement executed by the parties.   Id.  at  6.
An actual license agreement, however, was later executed between Gruppe  and  Firstliner,  permitting
CAT’s use of the accused process.  Id.  This license agreement stated that “[t]he licensee  has  been
informed of a threat of a possible claim for infringing the INSITUFORM method.”  Id.
      The original accused process used by defendants—referred to as the “Multiple  Cup  Process”  or
“Process 1”—was a method of tube liner impregnation involving the serial application of vacuum  cups.
 In Process 1, from four to six cups were used to draw a vacuum from a corresponding number of  slits
in the tube liner.  As a result, when the cup closest to the advancing resin  was  removed,  and  its
slit was sealed, the remaining downstream cups continued to draw a vacuum in the tube liner.
      At some point in either 1991 or early 1992, on the advice of counsel, defendants switched to an
alternate process.  In the  alternate  process—referred  to  as  the  “Multiple  Needle  Process”  or
“Process 2”—the multiple cups were replaced with multiple metal tubes, known as needles.  In  Process
2, the needles are inserted through the layers of the impregnated  tube  liner,  rather  than  merely
placed over holes in the wall of the liner.  Defendants did not develop Process  2  until  after  the
first phase of the case had already been tried to a jury.
      The original action for infringement of the ‘012 patent was  brought  in  February  1990.   The
original plaintiffs  were  Insituform  of  North  America,  Inc.;  Insituform  Licensees,  B.V.;  and
Insituform Gulf.  Insituform Licensees, B.V. was the owner of the ‘012 patent at the commencement  of
the suit.  As explained more fully below, Insituform Licensees, B.V. subsequently assigned  the  ‘012
patent to Insituform Netherlands, along with the right to  sue  for  past  infringement.   Insituform
Netherlands  was  thus  eventually  substituted  for  Insituform  Licensees,  B.V.  as  a  plaintiff.
Insituform Technologies, Inc. (“ITI”) is the parent company and administrative headquarters  for  the
Insituform organization, including Insituform Gulf.  Id. at 4.  Insituform Gulf is authorized  to  do
business in Louisiana, Mississippi, and Texas  and  licensed  to  perform  Insituform  technology  in
designated regions throughout the United States.[1]  Id. at 5.  Insituform of North America, Inc.  is
no longer a party to the suit.
      Only claim 1 of the ‘012 patent was asserted at trial.  It recites
                 1. A method of impregnating with a curable resin an inner layer of  resin  absorbent
           material disposed in an elongate flexible  tube  having  an  outer  layer  formed  by  an
           impermeable film, the method comprising the steps of
                 (1) introducing into one end of the elongate  tube  a  mass  of  the  curable  resin
           sufficient to impregnate the entire resin absorbent inner layer of the tube,
                 (2) forming a window in the impermeable outer layer of the tube at a  distance  from
           said one end of the tube,
                 (3) drawing through the window a vacuum in the interior of the  tube  downstream  of
           said one end by disposing over the window a cup connected by a flexible hose to a  vacuum
           source which cup prevents ingress of air into the interior of the tube while the tube  is
           being evacuated, the outer layer of the tube being substantially impermeable to air,
                 (4) beginning at or near the end at which the curable  resin  mass  was  introduced,
           passing the tube between squeezing members which force the  resin  to  flow  towards  the
           region of vacuum application as the tube progresses through the squeezing members,
                 (5) when the resin reaches  the  vicinity  of  the  region  of  vacuum  application,
           removing the cup and sealing the window,
                 (6) providing another window in the impermeable layer of the tube downstream of  the
           previously formed window,
                 (7) drawing through the new window a vacuum  in  the  interior  of  the  tube  while
           progressively moving the tube through the squeezing members to force the  resin  to  flow
           toward the new region of vacuum application, and
                 (8) repeating steps 5, 6, and 7, where necessary  to  impregnate  the  entire  resin
           absorbent inner layer of the flexible tube.


‘012 patent, col. 6, l. 37 – col. 7, l. 6.
      The case was first tried to a jury in June 1991.  The jury returned a  verdict  that  the  ‘012
patent was not invalid and was infringed, both literally and via equivalents, by Process 1, the  only
accused process  then  at  issue.   The  district  court  granted  defendants’  motion  for  judgment
notwithstanding the verdict (“JNOV”) with respect to literal infringement and ordered a new trial  as
to infringement under the doctrine of equivalents.  In June  1994,  the  case  was  reassigned  to  a
different judge.  A bench trial was held in February 1995, and in November of  that  year  the  court
held that Process 1 and Process 2 (which had been introduced after  the  1991  trial)  infringed  the
‘012 patent under the doctrine of equivalents.  The court held defendants CAT,  Firstliner,  and  MSC
liable for direct infringement.   The  court  also  found  CAT  and  Firstliner  liable  for  induced
infringement.  Additionally, the court found that KS  also  had  induced  infringement  of  the  ‘012
patent.  Defendants appealed.
B. Insituform I
      On appeal, we ruled that claim 1 of the ‘012 patent, which recites use of a single cup moved to
different windows along the tube to draw a vacuum, did not encompass the  accused  methods  of  using
several cups or several needles attached at different  points  along  the  tube,  and  thus  was  not
literally infringed by either Process 1 or Process 2.  Insituform Techs., Inc.  v.  Cat  Contracting,
Inc., 99 F.3d 1098, 1106-07 (Fed. Cir. 1996) (“Insituform I”).  We also ruled  that  plaintiffs  were
not barred by prosecution  history  estoppel  from  asserting  infringement  under  the  doctrine  of
equivalents.  Id. at 1107-08.  Finally, we ruled that the district  court  had  erred  in  construing
claim 1.  We therefore vacated the judgment of infringement with respect to both processes under  the
doctrine of equivalents and remanded the case for  new  findings  regarding  infringement  under  the
doctrine of equivalents under the correct claim construction.  Id.  Because we vacated  the  judgment
of direct infringement, we did not reach the issue of whether KS  had  induced  infringement  of  the
‘012 patent.
C. Insituform II
      On remand, the district court again held that claim 1 of the ‘012 patent was infringed by  both
Process 1 and Process  2  under  the  doctrine  of  equivalents.   Insituform  Techs.,  Inc.  v.  Cat
Contracting, Inc., CA No. H-90-1690 (S.D. Tex. Dec.  31,  1996).   The  court  subsequently  enjoined
defendants from practicing those processes.  In addition, the court ruled again that KS  had  induced
infringement of the ‘012 patent.  Defendants again appealed.
      On the second appeal to us, we  reaffirmed  that  prosecution  history  estoppel  did  not  bar
plaintiffs from asserting infringement under the doctrine of equivalents.   Insituform  Techs.,  Inc.
v. Cat Contracting, Inc., 166 F.3d 688, 692 (Fed. Cir. 1998) (“Insituform II”).  On the  infringement
issue, insofar as Process 1 was concerned, we affirmed the district court’s holding that the  process
infringed claim 1 of the ‘012 patent under the doctrine of equivalents.  Id. at 693.   However,  with
respect to Process 2, we held that there were substantial differences between the claimed single  cup
process and the accused multiple needle process.  Id. at 694.  Accordingly, we reversed  the  court’s
holding that Process 2 infringed.  Id.
      Turning to the liability  of  KS[2]  for  induced  infringement,  we  noted  that  “a  separate
corporation related to [KS] licensed the infringing technology to [Firstliner]  after  [KS]  received
notice of the ‘012 patent.”  Id. at 695.  That corporation was Gruppe.   Because  Gruppe  was  not  a
party to the case, and because “there were no findings that this affiliate was [KS]’s alter ego,”  we
vacated the district court’s holding and remanded for further proceedings on  the  inducement  issue.
Id.
D. Insituform III
      On remand, the district court determined that Gruppe was not the alter ego of KS and  that  KS,
therefore, was not liable for  induced  infringement.   District  Court  Opinion,  slip  op.  at  45.
Additionally, the district court joined Giulio Catallo in his personal capacity as a  defendant,  and
held him jointly liable for damages.  Joinder Order, slip op. at 9.   With  both  the  liability  and
damages trials now concluded, the court awarded damages  for  infringement  of  the  ‘012  patent  by
Process 1 under the doctrine of equivalents.  District Court Opinion, slip op. at 62.   Additionally,
the court found CAT and Firstliner’s infringement to be willful and thus enhanced the actual  damages
award by fifty percent, id. at 55, and awarded Insituform attorney fees, id. at 57.
      Defendants appealed, raising  a  number  of  different  issues.   These  included  (1)  whether
Insituform Netherlands, the new assignee of  the  ‘012  patent,  had  been  improperly  joined  as  a
plaintiff; (2) whether Giulio Catallo, as  president  of  CAT,  had  been  improperly  joined  as  an
individual defendant jointly and severally liable for damages; (3) whether  the  district  court  had
properly assessed damages following our decision in Insituform II; (4)  whether  the  district  court
had erred in holding that the infringement that was found in the case was willful;  and  (5)  whether
the district court had  erred  in  determining  the  extent  to  which  accused  infringers  CAT  and
Firstliner instructed, and therefore induced, their licensees to use  the  infringing  process.   For
their part, plaintiffs cross-appealed the district court’s ruling that Gruppe was not the  alter  ego
of KS and that KS therefore was not vicariously liable for induced infringement.
      After oral argument in the appeal, defendants filed motions asking us to apply our  holding  in
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 234 F.3d 558 (Fed. Cir.  2000)  (en  banc)
(“Festo I”).  In Festo I, we ruled that a narrowing amendment  to  a  claim  limitation  made  for  a
substantial reason related to patentability completely  bars  the  application  of  the  doctrine  of
equivalents to that amended claim limitation.  Id. at 569.  Because our Festo I decision  represented
an intervening change in controlling authority, we revisited our infringement holdings in  Insituform
I and II.  Insituform Techs., Inc. v. Cat Contracting, Inc., 10 Fed. Appx. 871, 877 (Fed. Cir.  2001)
(unpublished) (“Insituform III”).
      After reexamining the prosecution history of the ‘012 patent, we determined that,  under  Festo
I, Insituform had made a narrowing amendment to claim 1 of the ‘012 patent.  Insituform III, 10  Fed.
Appx. at 879-80.  The claim was narrowed, we pointed out, because claim 1 in its  original  form  did
not limit the number of cups that could be used to create a vacuum, whereas claim 1  in  its  amended
form was limited to the use of one cup.  Id.  Accordingly, we held  that  “Insituform  cannot  assert
any range of equivalents for this claim limitation [and] Process 1, which uses multiple cups,  cannot
infringe under the doctrine of equivalents,  the  only  finding  of  infringement  affirmed  by  this
court.”  Id. at 880.  We therefore reversed the district court’s  final  judgment  of  liability  and
damages, and remanded the case with instructions “(i) to vacate all orders entered after the  finding
of infringement as moot, including those relating to damages and Catallo’s joinder as defendant;  and
(ii) to dismiss the case as to all parties.”  Id.  We thus did  not  address  the  several  remaining
issues noted above that originally were on appeal to us in  Insituform  III.   Plaintiffs  petitioned
the Supreme Court for a writ of certiorari, as did the plaintiff in Festo I.
E. Remand from the Supreme Court
      The Supreme Court vacated and remanded our decision  in  Festo  I.   Festo  Corp.  v.  Shoketsu
Kinzoku Kogyo Kabushiki Co., Ltd., 525 U.S.  722  (2002)  (“Festo  II”).   In  Festo  II,  the  Court
overruled the complete bar we established in Festo I, establishing a flexible bar  instead.   Id.  at
738 (“[W]e have consistently applied the doctrine [of equivalents] in a flexible  way,  not  a  rigid
one.”).  The Court also held, inter alia, that where the equivalent was “unforeseeable  at  the  time
of the amendment” or the rationale underlying the amendment bore “only a peripheral relation” to  the
equivalent,  the  patentee  could  rebut  the  so-called  “Festo-presumption.”   Id.  at  740.   That
presumption is that a narrowing amendment made for a reason of patentability  surrenders  the  entire
territory between the original and  the  amended  claim  limitation.   Id.   Accordingly,  the  Court
vacated our decision in Insituform III and remanded the case to us for further proceedings  in  light
of its decision in Festo II.  Insituform Techs.,  Inc.  v.  Cat  Contracting,  Inc.,  535  U.S.  1108
(2002).
F. Festo III
      After the Supreme Court remanded Festo to us, we rendered our second en banc  decision  in  the
case.  Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 344  F.3d  1359  (Fed.  Cir.  2003)
(“Festo III”).  In Festo III, we summarized the three ways in which the  Supreme  Court  stated  that
the Festo presumption could be rebutted.  Id. at 1369.  First,  the  patentee  may  demonstrate  that
“the alleged equivalent would have been unforeseeable at the time of the narrowing  amendment.”   Id.
Second, the patentee may demonstrate that “the rationale underlying the narrowing amendment  bore  no
more than a tangential relation to the equivalent in question.”  Id.  Finally, there  may  be  “‘some
other reason’ suggesting that the patentee could not reasonably have been expected to have  described
the alleged equivalent.”  Id. (citing Festo II, 535 U.S. at 740-41).
                                               ANALYSIS
      The following issues are now before us on direct appeal:  (1)  whether  plaintiffs  are  barred
from asserting infringement under the doctrine  of  equivalents  by  reason  of  prosecution  history
estoppel in light of Festo II and Festo III; (2) whether Insituform Netherlands, the new assignee  of
the ‘012 patent, was improperly joined as a plaintiff; (3) whether Giulio Catallo, president of  CAT,
was improperly joined as an individual defendant and held jointly and severally liable  for  damages;
(4) whether the district court properly assessed damages following our  decision  in  Insituform  II;
(5) whether the district court erred in holding that the infringement that was  found  in  this  case
was willful; and (6) whether the district court erred in determining  the  extent  to  which  accused
infringers CAT and Firstliner instructed their licensees to use the infringing  process.   On  cross-
appeal, we consider whether the district court erred in ruling that Gruppe was not the alter  ego  of
KS, and that KS therefore was not vicariously  liable  for  induced  infringement.   We  address  the
parties’ contentions in turn, beginning with the Festo issue.
                                                  I.
      With the complete bar of Festo I overturned, we asked the parties to give us their views as  to
how we should decide the case in light of Festo II and Festo III.  In response, both  plaintiffs  and
defendants urged us to decide the Festo issue on the record now before us.   We  of  course  are  not
bound by the wishes of the parties on a question such as this.  However, because  resolution  of  the
issue turns on whether Insituform’s rationale underlying the narrowing amendment bore no more than  a
tangential relation to accused Process 1, and because the record has been  fully  developed  on  this
point, we agree that we can decide the issue.  See Festo  III,  344  F.3d  at  1370  (“[W]hether  the
patentee has established a merely tangential reason for a narrowing amendment is  for  the  court  to
determine from the prosecution history  record  without  the  introduction  of  additional  evidence,
except, when necessary, testimony from those skilled in the art as  to  the  interpretation  of  that
record.”).
      Plaintiffs urge that nothing in either Festo II or Festo III invalidates Insituform  II,  where
we determined that plaintiffs  were  not  barred  by  prosecution  history  estoppel  from  asserting
infringement under  the  doctrine  of  equivalents.   Plaintiffs  contend  that  any  presumption  of
surrender is rebutted because the rationale underlying the amendment narrowing claim 1  to  a  single
cup process bears at most a tangential relation to the infringing equivalent—the multiple-cup  method
of Process 1.  Specifically, plaintiffs assert that the reason for the amendment was to overcome  the
prior art teaching of a single vacuum source at the far end of the tube liner.  As  such,  plaintiffs
argue, the amendment is, at most, only tangentially related to Process 1, which places multiple  cups
near the resin front.
      For their part, defendants note that claim 1, as originally  filed,  covered  a  process  using
single or multiple cups at any location downstream of the resin front.  See Insituform I, 99 F.3d  at
1108.  They also note that we construed claim 1, as amended, to cover  a  single  vacuum  cup,  which
inherently creates a discontinuous vacuum.  Id. at 1106.  Defendants thus argue that accused  Process
1 falls squarely within the territory surrendered by the narrowing amendment.
      For the reasons which follow, we hold that plaintiffs have rebutted the Festo presumption  that
a narrowing amendment made for a reason of patentability surrenders the entire territory between  the
original claim limitation and the amended claim limitation.  See Festo II, 535 U.S.  at  740-41.   We
reach this conclusion because  we  conclude  that  the  prosecution  history  establishes  that  “the
rationale underlying” the amendment narrowing the scope of literal claim coverage from multiple  cups
to a single cup bears “no more than a tangential relation to the  equivalent  in  question,”  accused
Process 1.  Id.  Therefore, application of the doctrine of equivalents in this case was  not  barred.
Accordingly, we again affirm the judgment of the district court that Process 1 infringed claim  1  of
the ‘012 patent under the doctrine of equivalents.[3]
      In Insituform I, we construed claim 1 of the ‘012 patent as limited to “a  process  using  only
one vacuum cup which inherently creates a discontinuous vacuum.”   Id.  at  1106.   Based  upon  that
construction, we affirmed the district court’s JNOV that Firstliner’s Process 1,  employing  multiple
cups beyond the resin, did not literally infringe claim 1.  Id.  As noted,  we  also  held,  however,
that Insituform was not barred  by  prosecution  history  estoppel  from  asserting  that  Process  1
infringed claim 1 under the doctrine of equivalents.  Id. at 1109.  In so holding,  we  first  looked
at the original claims in Insituform’s application.  Of those, only the first four  are  relevant  to
this appeal.  Those claims recited:
           1. A method of impregnating a flexible tube comprising an inner layer of resin  absorbent
           material and an outer layer in the  form  of  an  impermeable  film,  wherein  the  resin
           absorbent layer is impregnated with a curable resin by applying a vacuum to the inside of
           a flexible tube whilst the resin is brought into  impregnation  contact  with  the  resin
           absorbent material, the impermeable film serving as a means to  prevent  ingress  of  air
           into the interior of the tube, whilst the impregnation process is taking place.


           2. A method according to claim 1, wherein the resin is introduced into  one  end  of  the
           tube in a quantity calculated effectively  to  impregnate  all  of  the  resin  absorbent
           material of the tube, and the vacuum is applied to the interior of the  tube,  downstream
           of the resin mass, so that the resin will tend to flow  towards  the  vacuum  application
           region.


           3. A method according to claim 2, wherein the lining tube containing the mass of resin is
           fed through a pressure applying nip, such as may be  defined  by  a  nip  roller,  which,
           together with the movement of the tube, squeezes the resin in  a  direction  towards  the
           region of the application of the vacuum,  at  the  same  time  flattening  the  tube  and
           assisting in the even distribution of the resin.


           4. A method according to claim 2, wherein the vacuum is applied through a window  in  the
           film in the wall of the tube by means of a cup applied to said window and connected to  a
           source of vacuum by means of a flexible hose, whereby the cup  can  move  with  the  tube
           during its movement relative to said nip, the cup being moved and applied to  a  position
           spaced downstream from the previous window, said previous window being sealed by means of
           a patch or the like, whereby the process is repeated for respective lengths of  the  tube
           until the entire tube length has been impregnated.


As can be seen, the position and number of vacuum cups were not specified  in  independent  claim  1.
Neither did claim 1 specify the location of the vacuum source.  Dependent claim  2  referred  to  the
vacuum being applied to the interior of the tube, “downstream of the  resin  mass,”  while  dependent
claim 3 stated that the resin is squeezed “in a direction towards the region of  the  application  of
the vacuum.”  It was only in dependent claim 4 that the inventor recited application  of  the  vacuum
through a window in the wall of the tube by means of  a  cup  applied  to  the  window,  as  well  as
repositioning of the cup.  All four claims were rejected over United States Patent No.  4,182,262  to
Everson (“Everson”).
      We stated in Insituform I that the original four claims  “were  rejected  over  Everson,  which
discloses both the use of a continuous vacuum and the creation of that  vacuum  from  only  a  single
vacuum source at the far end of the tube opposite the resin source.”  Id.  at  1108.   The  objection
was overcome by amending claim 1 to include,  in  a  different  form,  the  limitations  of  original
dependent claims 2-4.  Further examining the prosecution history, we determined that  Insituform  had
stated to the examiner that the problem with Everson was that Everson’s method was  ineffective  when
dealing with a long length of tube because it required an exceedingly large suction  compressor.   We
pointed out that Insituform solved this problem by placing the suction source  closer  to  the  resin
front, thus allowing the use of a smaller suction compressor.  Id.  Based on our examination  of  the
prosecution history, we concluded that Insituform was not  estopped  from  asserting  that  Inliner’s
multiple cup process infringed claim 1 of the ‘012 patent under the doctrine of equivalents:
           [I]t cannot  be  said  that  a  reasonable  competitor  could  conclude  that  Insituform
           relinquished coverage of processes using either multiple vacuum sources or  a  continuous
           vacuum.  At no point did Insituform indicate that the Everson  problem  could  be  solved
           only in the manner used by Insituform, i.e., Insituform never  stated  that  the  problem
           could not be solved by using more than one vacuum source or a continuous vacuum.  Rather,
           the only express limitation put on the invention by Insituform was the use  of  a  vacuum
           source close to the resin.

Id. at 1109.  We remanded the case to the district court for further proceedings on  whether  Process
1 infringed claim 1 under the doctrine of equivalents.
      On remand, the district court held that Process 1 infringed  claim  1  under  the  doctrine  of
equivalents, and the case returned to us on appeal in Insituform II.  On  appeal,  Firstliner  argued
that Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997), issued  after  Insituform
I, limited the doctrine of equivalents so that it could not apply in the  case.   Firstliner  pointed
to Warner-Jenkinson’s holding that where no  explanation  is  given  for  an  amendment  made  during
prosecution of a patent, a presumption is to be applied against the patentee that the  amendment  was
made for purposes of patentability.  Firstliner asserted that when  Insituform  amended  claim  1  in
response to the examiner’s 35 U.S.C. § 103 rejection over Everson, it necessarily  gave  up  coverage
of any process in which the vacuum was created at multiple vacuum  sources  because  it  provided  no
explanation for that narrowing  amendment.   Insituform  II,  161  F.3d  at  691.  We  rejected  this
argument, pointing out that,  during  prosecution,  Insituform  had  explained  the  reason  for  the
amendment of claim 1:
           The stated reason . . . for Insituform’s amendment to overcome the Everson reference  was
           to avoid the need to use a large compressor when the  vacuum  is  created  a  significant
           distance from the resin source.  The Warner Jenkinson presumption, therefore, which comes
           into play only when no explanation is given for a claim amendment, is not  applicable  to
           this case because Insituform made clear that the reason for the amendment was to overcome
           the prior art teaching creation of a single source vacuum at the far end of the liner.

Id. at 692 (citation omitted, emphasis in original).  Having rejected Inliner’s  prosecution  history
estoppel argument, we went on to affirm the district  court’s  judgment  of  infringement  under  the
doctrine of equivalents.  Id. at 692-93.  As noted  above,  however,  we  subsequently  reversed  the
judgment of infringement in Insituform III based on our short-lived complete bar rule arising out  of
Festo I.
      In our view, Insituform has rebutted the Festo presumption.  The prosecution  history  and  our
discussion of that history in Insituform I and II compel the conclusion that the  amendment  limiting
the literal scope of claim 1 to a single cup process bears “only a  tangential  relation,”  if  that,
“to the equivalent in question,” a process using multiple cups.  The  question  we  must  address  is
“whether the reason for the narrowing amendment was peripheral, or  not  directly  relevant,  to  the
alleged equivalent.”  Festo III, 344 F.3d at 1365.  As the discussion above indicates, the  narrowing
amendment in this case was for the purpose of distinguishing the invention over Everson.   Insituform
made it clear that the difference between its process and Everson was that its process did  not  have
the disadvantage of the Everson process of a large compressor at the end of the liner.  There  is  no
indication in the prosecution history of any relationship  between  the  narrowing  amendment  and  a
multiple cup process, which is the alleged equivalent in this case.  Thus, we  hold  that  plaintiffs
have successfully rebutted the Festo presumption by establishing that  the  amendment  narrowing  the
claimed invention from multiple cups to a single cup was tangential to accused Process 1, which  used
multiple cups attached at different points along the liner tube.  We therefore  affirm  the  judgment
of infringement under the doctrine of equivalents.
      Because we have sustained the judgment of infringement, we must consider the several additional
issues that were mooted when we reversed the judgment of infringement under the short-lived  complete
bar rule arising out of Festo I.
                                                 II.
      We consider first the issues raised by defendants in their direct  appeal.   Defendants  appeal
(1) the joinder of Insituform Netherlands, (2) the joinder of Catallo  in  his  individual  capacity,
(3) the  damages  award  for  infringement  by  Process  1,  (4)  the  district  court’s  willfulness
determination, and (5) the extent to which CAT/Firstliner induced infringement by their licensees.
A. Joinder of Insituform Netherlands
      Defendants appeal the joinder of Insituform Netherlands.  According to defendants, the  current
owner of the ‘012 patent, Insituform Netherlands, never filed suit and was named to  this  litigation
only because of a misrepresentation to the district court in 1994, after the case was  reassigned  to
a new judge.  They assert that the district court’s 1994 decision adding Insituform Netherlands as  a
party was in error and that no properly named party has standing  to  sue  for  damages.   Plaintiffs
respond that the district court acted well within its discretion  (i)  in  granting  the  joint  1994
motion that Insituform Netherlands be added as a party, and (ii) in refusing to alter  that  decision
in 1999.
      The original corporate plaintiff, and owner of the ‘012 patent, was Insituform  Licensees  B.V.
Insituform Licensees B.V. filed this lawsuit in 1990.  In 1992, the case  went  to  trial.   At  that
time, the plaintiffs  were  Insituform  Licensees  B.V.;  Insituform  of  North  America,  Inc.;  and
Insituform Gulf South, Inc.  The defendants were CAT, MSC, KS, and Firstliner.
      Following a jury trial, a verdict, and after a new trial was ordered, Insituform Licensees B.V.
assigned the ‘012 patent to Insituform Netherlands.  The assignment included the  right  to  sue  for
past infringement.  At the time of the assignment, Insituform Netherlands was  not  a  party  to  the
lawsuit, and it did nothing to join the suit for two  years.   On  November  30,  1994,  the  parties
entered a joint motion asking the court to make Insituform Netherlands a party.   The  motion  stated
that “legal title to the patent in suit has  been  transferred  from  Insituform  Licensees  B.V.  to
Insituform (Netherlands) BV.”  Plaintiffs also represented to defendants and to  the  district  court
that Insituform Licensees B.V. had  changed  its  name  to  Insituform  Netherlands.   This  was  not
technically true.  While ownership of the patent had, indeed,  changed  hands,  Insituform  Licensees
B.V. was still an existing corporate entity at the time of the motion.   After  the  motion  to  join
Insituform Netherlands was granted, defendants discovered the alleged misrepresentation and, on  that
basis, now challenge Insituform Netherlands’ standing.
      Probably to remedy what they perceived to be a potential defective parties problem, plaintiffs,
in 1999, sought leave to amend their pleadings to include Insituform North America, Inc.[4]  and,  if
necessary, Insituform Netherlands as parties under Fed. R. Civ. P. 15(a) and 21.  The district  court
stated that “[Insituform Netherlands] was made a party to  this  suit  by  order  of  this  court  on
November 30, 1994.”  District Court Opinion, slip op. at 21.  The court also stated that “the  rights
of the legal patent owner have been at issue since the inception of this case and . .  .  [Insituform
Netherlands] has presented evidence of recoverable monetary damages that Defendants  have  been  able
to rebut at trial.  Therefore, Defendants would not be  prejudiced  if  [Insituform  Netherlands]  is
recognized as a party plaintiff in this suit.”  Id. at 21-22.  In other  words,  the  district  court
ruled that it had already joined Insituform Netherlands as a party in November 1994, and  it  refused
to change that decision in 1999, despite the arguments of defendants.
      Because the joinder issue is not unique to patent  law,  we  apply  the  law  of  the  regional
circuit.  McGinley v. Franklin Sports, Inc., 262 F.3d  1339,  1357  (Fed.  Cir.  2001)  (“A  district
court’s decision to grant or deny a motion for leave to join a party involves a  procedural  question
that raises no  special  issues  relating  to  patent  law,  and  therefore  [regional  circuit]  law
applies.”); Datascope Corp. v. SMEC, Inc., 962 F.2d 1043, 1045 (Fed.  Cir.  1992)  (Regional  circuit
law determines “the standard for determining whether the district  court  abused  its  discretion  in
denying [the patentee] leave to amend” its complaint to add a new party.).  Rule 15(a) provides  that
a party may amend its pleadings “only by leave of court or by written consent of the  adverse  party;
and leave shall be freely given when justice so requires.”  Fed. R. Civ. P. 15(a).   Rule  21  states
that “parties may be dropped or added by order of the court on motion of any  party  or  of  its  own
initiative at any stage of the action and on such terms as are  just.”   Fed.  R.  Civ.  P.  21.   In
applying Rule 21, the court is governed by the  liberal  amendment  standards  of  Rule  15(a).   See
McLellan v. Miss. Power & Light, 526 F.2d 870, 873 (5th Cir. 1976).  The decision to grant or deny  a
motion for leave to amend thus lies within the sound discretion of  the  trial  court.   Jacobsen  v.
Osborne, 133 F.3d 315, 318 (5th Cir. 1998); Datascope Corp., 962 F.2d at  1045.   The  Fifth  Circuit
has stated that leave should be granted “in the absence of any apparent or  declared  reason—such  as
undue delay, bad faith or dilatory motive on the  part  of  the  movant,  repeated  failure  to  cure
deficiencies by amendments previously allowed, undue prejudice to the opposing  party  by  virtue  of
allowance of the amendment, [or] futility of amendment.”  Jacobsen, 133 F.3d at 318.
      The district court exercised its discretion in this case fully  aware  of  plaintiffs’  alleged
misrepresentation in the 1994 joint motion and determined that defendants would suffer  no  prejudice
were Insituform Netherlands joined as a party.  District  Court  Opinion,  slip  op.  at  21-22.   We
discern no abuse of discretion in this decision, and thus affirm the district court’s ruling.[5]   We
have considered the defendant’s other arguments on this point and find them not persuasive.
B. Joinder of Giulio Catallo
      Defendants appeal the joinder of Giulio Catallo as a  defendant  in  his  individual  capacity.
According to defendants, the addition of Catallo as a party to this suit  violated  due  process  and
was contrary to the Supreme Court’s decision in Nelson v. Adams U.S.A., Inc., 529  U.S.  460  (2000).
For their part, plaintiffs distinguish Nelson and rely on  our  decision  in  Fromson  v.  Citiplate,
Inc., 886 F.2d 1300 (Fed. Cir. 1989).  Plaintiffs assert that Catallo is the main  executive  officer
of both CAT and Firstliner and (1) had controlling authority of their day-to-day operations, (2)  was
directly and  actively  involved  in  all  aspects  of  the  litigation,  and  (3)  was  individually
responsible for all of the conduct that  led  the  district  court  to  increase  damages  and  award
attorney’s fees.  As explained below, the district court’s ruling on this point is supported  by  our
decision in Fromson, and we see no clear error in  the  court’s  interpretation  of  the  facts.   We
accordingly affirm the court’s decision on this point.
      Giulio Catallo is the sole owner of defendants CAT and Firstliner.  He  also  is  president  of
both corporations.  Plaintiffs first attempted to join Catallo in his individual capacity in  January
of 1991, before the first infringement trial in the case.  That motion was denied  without  prejudice
and without opinion.  Plaintiffs renewed their motion after the infringement  trial  (the  trial  for
damages was bifurcated) in July 1991.  This motion also was  denied  without  prejudice  and  without
opinion.  In each case, the reason asserted for the joinder of Catallo  was  that  he  was  “directly
responsible for all of the activities of CAT and INLINER [and] was clearly the  moving  force  behind
infringement [and] personally financially  benefited  from  the  payments  made  [under  one  of  the
contracts found to be infringing.]”  Additionally, plaintiffs asserted that Catallo was personally  a
licensee of the accused process because he signed a license agreement twice,  on  behalf  of  himself
and as President of Firstliner.
      The damages portion of the case was tried in September 1997.  After trial, the court found that
defendants’ infringement had been willful.  In July  1999,  plaintiffs  moved  again  to  add  Giulio
Catallo as a defendant.  In so doing, they argued that Catallo’s corporations  were  a  “real  credit
risk.”  They also argued that Catallo was a personal tortfeasor.  Finally, they  urged  that  in  the
intervening years (1991-1999) many facts had come to light that weighed in favor  of  making  Catallo
personally liable as an individual party.
      Defendants acknowledge that a corporate entity may be disregarded  if  doing  so  will  prevent
fraud, illegality, injustice, a contravention of public  policy,  or  prevent  the  corporation  from
shielding someone from criminal liability.  See Manville Sales Corp. v.  Paramount  Sys.,  Inc.,  917
F.2d 544, 552 (Fed. Cir. 1990).  They argue, however, that none of  these  reasons  were  present  in
this case.  They state that Catallo “was merely acting in accordance [with] the duties and  scope  of
his position” and that he “had a good faith belief and basis that  the  Firstliner  process  did  not
infringe any Insituform patents when the contracts were performed.”   In  short,  defendants  contend
that there was no reason to pierce the corporate veil in this case.
      In an August 30, 1999 order, the district court  granted  plaintiffs’  motion  to  join  Giulio
Catallo.  Joinder Order, slip op. at 9.   In  granting  this  third  request  to  add  Catallo  as  a
defendant, the district court recognized that it was faced “with  the  uncommon  situation  where  an
individual is sought to be added as a party after the conclusion of trial.”  Id. at 5.  With  respect
to the propriety of adding Catallo as a defendant, the district court relied on our decision in  Ohio
Cellular Products Corp. v. Adams, U.S.A., Inc., 175 F.3d  1343  (Fed.  Cir.  1999),  rev’d  sub  nom.
Nelson v. Adams, U.S.A., Inc., 529 U.S. 460 (2000), which was,  at  that  time,  pending  before  the
Supreme Court.  The court also pointed to our decision in Fromson.   With  respect  to  the  personal
liability of Catallo, the court relied on Walker v. Federal Deposit Insurance Corp.,  970  F.2d  114,
122 (5th Cir. 1992), where the Fifth Circuit stated that “[a]n officer  is  individually  liable  for
any tortious conduct that he committed in connection with  his  corporate  duties  .  .  .  .   If  a
corporate officer knowingly participates in a tortious act, there is no need to pierce the  corporate
veil in order to impose liability.”  In light  of  the  facts  that  led  to  a  finding  of  willful
infringement, and because the court believed that Catallo “was personally responsible  for  many,  if
not all, of the aggravating facts which  led  this  court  to  award  attorney’s  fees  and  enhanced
damages,” Joinder Order, slip op. at 7, it granted the motion to add Catallo as a  defendant  in  his
individual capacity, id. at 9.
      As noted above, because the amendment of a pleading to add a party is not unique to patent law,
we apply the law of the regional circuit.  McGinley, 262 F.3d at 1357.  We  thus  review  a  district
court’s decision to add a party pursuant to Rules 15 and 21 of the Federal Rules of  Civil  Procedure
for an abuse of discretion.  Jacobsen, 133 F.3d at 318.  Our decision in Ohio  Cellular,  upon  which
the district court relied, was subsequently overturned by the Supreme Court.   Nelson,  529  U.S.  at
472.  Resolution of this issue thus turns on whether the facts of this case fall more  closely  under
the Supreme Court’s decision in  Nelson,  or  our  decision  in  Fromson,  which  the  Supreme  Court
distinguished in Nelson.  If the facts are closer to Nelson, then  the  district  court  decision  is
incorrect as a matter of law, and Catallo  was  improperly  joined.   If  the  facts  are  closer  to
Fromson, then the district court decision should be affirmed.
      In Nelson, Ohio Cellular Products Corp. (“OCP”) sued Adams, U.S.A., Inc. (“Adams”)  for  patent
infringement.  Eventually, the action was dismissed and Adams was awarded costs  and  attorney  fees.
Nelson, 529 U.S. at 462.  Adams, fearful that OCP  would  be  unable  to  pay,  moved  to  amend  its
pleadings pursuant to Fed. R. Civ. P. 15 to include Nelson, the sole shareholder of OCP, as a  party.
 Id.  The district court granted the motion and simultaneously subjected Nelson to  the  judgment,  a
decision we subsequently affirmed in Ohio Cellular.
      The Supreme Court reversed our decision in Ohio Cellular on due  process  grounds.   The  Court
determined that Nelson was never afforded a proper opportunity to respond to the claim  against  him.
Id. at 467.  He was never served with an  amended  pleading,  nor  was  any  such  pleading  actually
composed and filed in the court.  Id. at 466.  Nor, after the amendment naming him as  a  party,  was
Nelson accorded ten days to state his defenses against personal liability for costs  and  fees.   Id.
Instead, judgment was entered against him the moment permission to amend the  pleading  was  granted.
Id.  The Court stated that “appeal after judgment, in the circumstances this case presents,  did  not
provide an adequate opportunity to defend against the imposition of liability.”   Id.   Finally,  the
Court noted that Adams never once sought to sue Nelson individually until after judgment was  entered
against Ohio Cellular.  Id. at 467.
      In Fromson, Citiplate, Inc. (“Citiplate”) was sued by Howard A. Fromson (“Fromson”) for  patent
infringement.  Fromson moved before trial to add the  individual  owners  of  Citiplate  as  parties,
because he suspected that the defendant corporation might not be able to pay a judgment  against  it.
Fromson, 886 F.2d at 1301.  The district court initially  denied  the  motion  because  of  defendant
Citiplate’s assurances that its financial condition was sound.  Id.  These assurances turned  out  to
be false.  After judgment had  been  entered,  the  court  allowed  Fromson  to  amend  its  original
complaint to add the individual owners of Citiplate as parties pursuant to Fed.  R.  Civ.  P.  15(c).
Id. at 1302.
      We affirmed the district court’s decision.  In so doing, we relied upon the test articulated by
the Supreme Court in Schiavone v. Fortune, Inc.,  477  U.S.  21  (1986),  to  determine  whether  the
requirements of Rule 15(c) had been met.  In Schiavone, the Court articulated a four-part test:
           Relation back is dependent upon four factors, all of which must  be  satisfied:  (1)  the
           basic claim must have arisen out of the conduct set forth in the original  pleading;  (2)
           the party to be brought in must have received such notice that it will not be  prejudiced
           in maintaining its defense; (3) that party must or should have  known  that,  but  for  a
           mistake concerning identity, the action would have been brought against it; and  (4)  the
           second and third requirements must have been fulfilled within the prescribed  limitations
           period.

Schiavone, 477 U.S. at 29.  Based on this  test,  we  determined  that  the  “identity  of  interests
between Citiplate and [its individual owners] is virtually complete and that [the individual  owners]
should have known all along that joinder  was  a  possibility.”   Fromson,  886  F.2d  at  1304.   We
concluded that the owners of Citiplate “themselves created the ‘mistake’ respecting the  identity  of
the proper party rightfully to be sued and capable of responding to damages.”  Id.
      The original 1991 motions to add Giulio Catallo presumably were  denied  because  the  district
court believed defendants’ assertions that Catallo  “was  merely  acting  in  accordance  [with]  the
duties and scope of his position” and that he “had a good faith belief and  basis  that  the  Inliner
process did not infringe any Insituform patents when the contracts were  performed.”   When  all  the
facts were determined following the 1997 damages trial, the court  concluded  that  these  assertions
were not true, finding that Catallo “was  personally  responsible  for  many,  if  not  all,  of  the
aggravating facts which led this court to award  attorney’s  fees  and  enhanced  damages.”   Joinder
Order, slip op. at 7.  Furthermore, the court found that “Catallo diligently  acted  to  protect  his
interests at every stage of the proceedings.”  Id.  The court subsequently exercised  its  discretion
and granted the motion requesting that Catallo be added as a defendant.
      Applying the Fifth Circuit’s abuse of discretion standard, we  cannot  say  that  the  district
court abused its discretion in adding Catallo as a defendant in  his  individual  capacity.   In  our
view, the controlling case is Fromson, which the  Supreme  Court  distinguished  in  Nelson.   As  in
Fromson, plaintiffs in this case sought from the very beginning to add Catallo as a defendant in  his
individual capacity on the theory that he was liable as an individual  tortfeasor.   We  have  stated
that “it is well settled that corporate officers  who  actively  aid  and  abet  their  corporation’s
infringement may be personally liable for inducing infringement under § 271(b) regardless of  whether
the corporation is the alter ego of the corporate officer.”  Orthokinetics,  Inc.  v.  Safety  Travel
Chairs, Inc., 806 F.2d 1565, 1579 (Fed. Cir. 1986).  The facts of this case  are  closer  to  Fromson
than to Nelson.  Accordingly, we affirm the decision of the district court.
C. Damages
      The overarching issue with respect  to  damages  is  the  propriety  of  the  district  court’s
procedure in reassessing damages  in  light  of  our  decision  in  Insituform  II.   The  issues  of
infringement and damages were bifurcated  in  the  case.   The  damages  trial  concluded  while  the
appealed infringement decision still was pending before us in Insituform II.  The damages  trial  was
conducted under the assumption that Process 1  (using  cups)  and  Process  2  (using  needles)  both
infringed the ‘012 patent.  We determined, however, that only Process 1 infringed and that Process  2
did not.  Insituform II, 161 F.3d at 694.  Not knowing that the damages trial had already  concluded,
we stated that “the bifurcated  damages  trial  will  determine  for  what  amount  [defendants  are]
actually responsible . . . .”  Id. at 695.
      Following our decision in Insituform II, the district court, over the objection of  defendants,
chose to allow only limited discovery to address the issue of damages, instead of  again  opening  up
trial proceedings.  District Court Opinion, slip op. at 3-4.  The primary issue on  which  the  final
damages award turned was one of fact.  Specifically, the district court had to determine the date  on
which defendants stopped using infringing Process 1 and started using the non-infringing  Process  2.
Id. at 35-36.  To that end, the court turned to the June 1991  trial  testimony  of  Giulio  Catallo,
which indicated that defendants switched to Process 2 “sometime after June of 1991.”  Id.  at  35.[6]
Defendants urged the court to rely instead on Catallo’s  February  1995  trial  testimony,  where  he
indicated that defendants had shifted to needles exclusively by  March  of  1991.   Id.   During  the
discovery period, defendants presented deposition testimony of two additional  witnesses  to  support
their assertion that February 14, 1991, was the actual date by which they had stopped  using  Process
1.  This testimony was offered to establish a specific date and to buttress Catallo’s  February  1995
testimony.  Id. at 35-36.
      Based on Catallo’s previous testimony at the  1991  and  1995  trials,  and  the  new  evidence
presented during discovery, the district court amended its damages ruling.   The  court  stated  that
the deposition testimony of the two additional witnesses “do[es] nothing to persuade the  Court  that
needles were actually being used for production purposes during the first quarter of 1991.”  Id.   In
conclusion, the court found that “the totality of the testimony  of  these  witnesses  does  make  it
appear credible that Defendants had switched to needles for production by the end of 1991  .  .  .  .
Therefore, for purposes of these damages calculations, the court finds that a  preponderance  of  the
evidence necessitates that the Court enter a finding that Defendants  had  switched  to  the  use  of
Process 2 for production by the beginning of 1992.”  Id. at 36.
      Defendants argue on appeal that rendition of judgment without a trial specifically focusing  on
damages relating to Process 1 violated their due process rights and our  mandate  in  Insituform  II.
For their part, plaintiffs respond that there  was  no  procedural  error  in  the  district  court’s
damages calculation because, in their view, the district  court  did  not  make  credibility  choices
except as to Catallo’s testimony in open court.  Additionally, plaintiffs argue that the due  process
requirements in a civil case, where only property interests are at stake,  are  much  less  stringent
than in criminal cases.
      We agree with defendants that “the procedure chosen by the district  court  in  this  case  was
tantamount to a ‘trial by affidavit’  which  has  long  been  disapproved  in  our  federal  judicial
system.”  Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255  (1986).   Defendants  characterize  the
trial court’s action as  a  “de  facto  summary  judgment”  proceeding  because  the  district  court
essentially ruled based on deposition and affidavit testimony without the opportunity to  observe  or
assess the credibility of  the  new  witnesses.   We  agree  with  defendants’  characterization  and
accordingly review the district court’s decision on this point under the summary  judgment  standard.

      We review summary judgment de novo.  Merck & Co., Inc. v. Mylan Pharms., Inc., 190  F.3d  1335,
1338 (Fed. Cir. 1999).  Summary judgment is appropriate where the record indicates “that there is  no
genuine issue as to any material fact and that the moving party  is  entitled  to  a  judgment  as  a
matter of law.”  Fed. R. Civ. P. 56(c).   We  believe  that  the  deposition  testimony  of  the  two
additional witnesses, combined with the inconsistent testimony of Catallo at the two  trials  created
a disputed issue of material fact upon which the  quantum  of  damages  turns.   The  district  court
should have resolved this issue with trial-type proceedings.  We therefore vacate and remand on  this
issue so that the trial court may properly weigh the new evidence regarding the  quantum  of  damages
attributable to infringing Process 1.
D. Willful Infringement
      The district court determined that  defendants  CAT  and  Firstliner’s  infringement  had  been
willful.  District Court Opinion, slip op. at  55.   One  crucial  aspect  of  the  district  court’s
willfulness determination was the failure of CAT and Firstliner to  obtain  an  opinion  of  counsel.
Id. at 52-54.  The district court stated  that  “due  to  a  complete  absence  of  competent  advice
regarding possible infringement of the ‘012 patent and a flagrant display  of  deliberate  misconduct
by CAT/[First]liner throughout this proceeding, the Court finds that  actions  of  CAT/[First]liner’s
evidenced the degree of willfulness necessary to support the award of enhanced damages.”  Id.  at  54
(emphasis added).  In our recent en banc decision in Knorr-Bremse Systeme  Fuer  Nutzfahrzeuge,  Gmbh
v. Dana Corp., Nos. 01-1357, -1376, 02-1221, -1256, slip op. at 11 (Fed. Cir.  Sept.  13,  2004),  we
addressed, inter alia, whether the failure of a defendant in a patent infringement suit to obtain  an
opinion of counsel “will provide an inference or evidentiary  presumption  that  such  opinion  would
have been negative.”  We held in Knorr-Bremse that “the failure to obtain an exculpatory  opinion  of
counsel shall no longer provide an adverse inference or presumption that such an opinion  would  have
been unfavorable.”  Id. at 12.  Such an inference was one factor upon which the district court  based
its willfulness determination in this case.  A determination of willfulness is made on  consideration
of the totality of the circumstances.  See Gustafson, Inc. v. Intersystems Indus. Prods.,  Inc.,  897
F.2d 508, 510 (Fed. Cir. 1990).  Because elimination of the adverse inference  arising  from  failure
to obtain an opinion of counsel is a material change in the totality of  the  circumstances  in  this
case, a fresh weighing of the evidence is required.  For this reason, we vacate the district  court’s
willfulness finding and remand for further proceedings.
E. Inducement of Infringement
      The district court determined that CAT and Firstliner  were  liable  for  induced  infringement
under 35 U.S.C. § 271(b) on account of work done by their licensees.  District  Court  Opinion,  slip
op. at 45.  CAT and Firstliner raise two  issues  related  to  their  alleged  induced  infringement.
First, they contend that there was a lack of proof with regard to the  scienter  element  of  induced
infringement.  Second, they contend that there was insufficient  evidence  to  sustain  the  district
court’s determination of damages related to the licensees’ use of infringing Process 1.
      Section 271(b) provides that “[w]hoever actively induces infringement  of  a  patent  shall  be
liable as an infringer.”  In order to succeed on a claim of inducement, the patentee must  show  both
direct infringement and a certain level of intent on the part of the alleged inducer that the  patent
be infringed.  Water Techs. Corp. v. Calco, Ltd., 850 F.2d  660,  668  (Fed.  Cir.  1988).   However,
there is a lack of clarity concerning whether the required  intent  must  be  merely  to  induce  the
specific acts or additionally to cause an infringement.  See Manville Sales Corp. v. Paramount  Sys.,
Inc., 917 F.2d 544, 553 (Fed. Cir. 1990) (“The plaintiff has the burden of showing that  the  alleged
infringer’s actions induced infringing acts and that he knew or should have known his  actions  would
induce actual infringements.”).  But see Hewlett-Packard Co. v. Bausch & Lomb, Inc., 909  F.2d  1464,
1469 (Fed. Cir. 1990) (“Proof of actual intent to cause the acts which  constitute  the  infringement
is a necessary prerequisite to finding active inducement.”).  Nevertheless, we need not  resolve  any
ambiguity in the case law on this point because there is sufficient evidence to support the  district
court’s finding under either standard.
      The  district  court  relied  on  Manville  and  applied  the  stricter  standard  for  induced
infringement, requiring that “the alleged infringer’s actions induced infringing  acts  and  that  he
knew or should have known his actions would induce actual  infringement.”   District  Court  Opinion,
slip op. at 40 (citing Manville, 917 F.2d at 553).  In finding the requisite intent, the court  noted
a response to a questionnaire submitted by one  of  CAT/Firstliner’s  licensees.   Id.  at  47.   The
licensee claimed to have used infringing Process 1 in 100 percent of its  contracts  and  that,  with
regard to how it acquired knowledge of the impregnation process, “[w]e  expected  to  get  directives
from [Firstliner] representatives, and we did.”  Id. at 47-48.  The  district  court  thus  concluded
that defendants taught their licensees to use Process 1.  Additionally, Firstliner did not begin  its
licensing program until 1992, which was after the original June 1991  trial.   CAT  and  Firstliner’s
licensing activity thus occurred with full knowledge that Process 1 had been  accused  of  infringing
the ‘012 patent.  On this evidence, the court determined that the intent requirement was met.
      Intent is a factual determination particularly within the province of the trier of fact and may
be inferred from all of the circumstances.  Water  Techs.,  850  F.2d  at  669.   We  review  factual
determinations by the court for clear error.  Tegal Corp. v.  Tokyo  Electron  Am.,  Inc.,  257  F.3d
1331, 1345-46 (Fed. Cir. 2001).  “A finding is ‘clearly erroneous’ when although  there  is  evidence
to support it, the reviewing court on the  entire  evidence  is  left  with  the  definite  and  firm
conviction that a mistake has been committed.”  United States v. United States Gypsum Co.,  333  U.S.
364, 395 (1948).  There is evidence in the record  to  support  the  district  court’s  finding  that
CAT/Firstliner induced infringement of the ‘012 patent and we are not  left  with  the  definite  and
firm conviction that a mistake has been committed.
      We now turn to the method the district court used to arrive at  the  quantum  of  damages.   To
assess damages, the court had to make findings as to the percentage of CAT/Firstliner licensees  that
were instructed to use infringing Process 1.  The issue before  us  is  whether  the  district  court
correctly determined the extent to which defendants CAT and Firstliner instructed their licensees  to
use the infringing Process 1, thereby inducing infringement under 35 U.S.C. § 271(b).   Specifically,
the issue is whether the district court’s method for determining  the  percentage  of  licensees  who
were instructed to use infringing Process 1 was flawed.  The parties agreed to  resolve  this  aspect
of the lawsuit by licensees’ questionnaire answers, subject to correction  by  deposition  if  either
party so desired.  District Court Opinion, slip op. at 45-46.  It appears  that  the  district  court
resolved this issue on the basis selected by the parties, and properly exercised  its  discretion  in
so doing.  Accordingly, we affirm the district court’s ruling on this point.
      Defendants assert that the district court clearly erred in its methodology in  determining  the
extent to which CAT/Firstliner instructed their licensees to use infringing  Process  1.   Primarily,
defendants argue that plaintiffs failed to carry their burden of proof with respect  to  the  royalty
revenue received by defendants CAT and Firstliner from use of  the  accused  Process  1.   Plaintiffs
respond that the parties stipulated to a procedure for establishing  the  extent  to  which  CAT  and
Firstliner instructed their licensees to use Process 1.  Plaintiffs argue that  the  district  court,
having resolved the issue in the manner selected and stipulated to by the parties,  should  be  given
full deference as the factfinder in the case.
      As part of the stipulated procedure for determining  the  extent  of  induced  infringement,  a
formal questionnaire was prepared and distributed to CAT/Firstliner’s licensees.  Only two  licensees
responded.  The first licensee said it was instructed to use Process 1; the second licensee  said  it
was instructed to use Process 2.  The district court noted that the response  to  the  questionnaires
was “admittedly less than satisfactory.”  District Court Opinion,  slip  op.  at  46.   However,  the
court judged that the poor response “was due in no small part to actions of Defendants in  publishing
statements in trade publications and in disseminating letters which implied that the finding of  this
Court would be  reversed.”   Id.  at  46-47.   The  court  concluded  that  “[b]ecause  this  limited
statistical sampling was caused by no fault of Insituform, the Court will  not,  as  Defendants  have
requested, limit Insituform’s damage claim for lack of supporting proof.   Instead,  the  Court  will
rely on these questionnaires in making its determination regarding the extent to which the  licensees
used the infringing methods and were induced to do so by the Defendants.”  Id. at  47.   Accordingly,
the district court determined that half of CAT and Firstliner’s  licensees  were  instructed  to  use
infringing Process 1, while half used non-infringing Process 2.
      “[C]ertain subsidiary decisions underlying a damage theory are discretionary  with  the  court,
such as . . .  [determining]  the  methodology  for  arriving  at  a  reasonable  royalty  [citations
omitted].  Such  decisions  are,  of  course  reviewed  under  the  abuse  of  discretion  standard.”
SmithKline Diagnostics, Inc. v. Helena Labs. Corp., 926  F.2d  1161,  1164  (Fed.  Cir.  1991).   “[A
court] may . . . adopt in its discretion a reasonable way  to  determine  the  number  of  infringing
units.  Such subsidiary choices are left to the court’s sound discretion under our  precedent.”   Id.
at 1165 n.2.  “Discretion, in this sense, is abused if the record contains  no  basis  on  which  the
district court rationally could have made its decision  or  if  the  judicial  action  is  arbitrary,
fanciful, or clearly unreasonable.”  Datascope Corp. v. SMEC, Inc., 879 F.2d 820, 827-28  (Fed.  Cir.
1989).
      We do not believe  that  CAT/Firstliner  has  shown  an  abuse  of  discretion  in  this  case.
Accordingly, we will not disturb the district court’s  ruling  that  at  least  half  of  defendants’
licensees used Process 1, while the other half used Process 2.  District Court Opinion, slip  op.  at
48.
                                                 III.
      We now address plaintiff’s cross-appeal.   Plaintiffs  appeal  the  district  court’s  decision
declining to hold KS liable for infringement based on an alter-ego theory  of  induced  infringement.
We begin with a brief review of the key entities and the facts  surrounding  the  alleged  alter  ego
relationship.
      KS is a German corporation, and is one of the named defendants in the lawsuit.  As noted above,
it is a sewer rehabilitation company, owned by Hans Mueller.  KS was (legally) using  the  Firstliner
process in Germany under a patent owned by Mueller, United States Patent  No.  4,770,562  (“the  ‘562
patent”).  KS is also the entity that initially met with Giulio Catallo and demonstrated to  him  use
of the accused process in Germany.  At that time, KS informed Catallo that it had  been  involved  in
patent litigation involving certain  European  patents  held  by  one  of  the  Insituform  entities.
Nevertheless, Catallo remained interested in the KS process, and KS signed  a  letter  of  intent  to
license the process to him.  KS also prepared a “To Whom  it  May  Concern”  letter  identifying  Mr.
Catallo as a “qualified licensee” of the process under the ‘562 patent.  It  is  undisputed  that  at
the time of these activities, KS was not aware of the ‘012 patent.  Insituform II, 161 F.3d  at  695.

      The non-party to whom plaintiffs are trying to link to KS via their alter ego argument is Kanal
Mueller Gruppe International GmbH & Co, a German corporation also owned by  Hans  Mueller,  which  we
refer to as “Gruppe.”  Gruppe is an export licensing company that was  formed  on  January  1,  1990.
Gruppe is a separate corporate entity from KS.  According to KS, Gruppe took over responsibility  for
licensing the accused process and Catallo, from that point forward, dealt with  Gruppe.   It  appears
that, at all times, Hans Mueller himself owned the relevant German patent and rights to  license  the
accused process.  He did not officially transfer those rights to Gruppe until 1995.
      The present lawsuit was filed on February 2, 1990.  At that time, Gruppe, KS, and Catallo first
became aware of the ‘012 patent.  Despite  the  lawsuit  and  notice  of  the  ‘012  patent,  Catallo
persisted in pursuing a  license  for  the  accused  process,  which  Gruppe  granted.   The  license
agreement was executed in July 1990 and provided that Gruppe was obligated to provide instruction  to
CAT/Firstliner employees sent to Germany, and to  provide  CAT/Firstliner  with  continued  technical
support.  Plaintiffs assert that KS, the sewer rehabilitation company  first  contacted  by  Catallo,
and not Gruppe, would have been the entity to provide  such  instruction  and  technical  support  to
CAT/Firstliner.  In other words, plaintiffs essentially seek to  impute  the  post-lawsuit  licensing
activity of non-party Gruppe to KS, who is the current party in the suit.  In  doing  so,  plaintiffs
argue that KS is the alter ego of Gruppe.
      The issue before the district court, as directed by this court in Insituform  II,  was  whether
Gruppe was the alter ego of KS.  Because the alter ego issue is not unique to patent law, this  court
applies the law of the regional circuit.  Panduit Corp. v. All States  Plastic  Mfg.  Co,  Inc.,  744
F.2d 1564, 1574-75 (Fed. Cir. 1984).  In the Fifth Circuit, “resolution of the  alter  ego  issue  is
heavily fact-specific and, as such, is peculiarly within the province of the  trial  court.”   United
States v. Jon-T Chems.,  Inc.,  768  F.2d  686,  649  (5th  Cir.  1985);  Bridas  Sapic  v.  Gov.  of
Turkmenistan, 345 F.3d 347, 360 (5th Cir. 2003) (“Alter ego determinations are highly fact-based  and
require considering the totality of the circumstances  in  which  the  instrumentality  functions.”).
The Fifth Circuit reviews alter ego determinations only for clear error.  Bridas Sapic, 345  F.3d  at
360.  We will thus reverse only if, after reviewing the evidence as a whole, we are  “left  with  the
definite and firm conviction that a mistake has been committed.”   United  States  v.  United  States
Gypsum Co., 333 U.S. 364, 395 (1948).  “Errors of law,  however,  are  not  entitled  to  deference.”
Bridas Sapic, 345 F.3d at 359.  It is an error of law if a district court fails to take into  account
all of the  aspects  of  the  relationship  between  the  entities  alleged  to  have  an  alter  ego
relationship.  Id. at 359-60.
      The district court correctly noted that, “[u]nder Texas law, a finding by the court  that  [KS]
is the alter ego of [Gruppe] permits the Court ‘to disregard the corporate  fiction  and  pierce  the
corporate veil, thereby attributing [Gruppe’s] infringing conduct to [KS].”  District Court  Opinion,
slip op. at 42 (citing Gundle Lining Constr. Corp. v. Adams County Asphalt, Inc., 85  F.3d  201,  208
(5th Cir. 1996)).  The court noted that “under the alter ego theory,  the  court  may  disregard  the
corporate form ‘where a corporation is organized and operated as a mere  tool  or  business  conduit’
for another entity.”  Id. at 43 (citing Zahra Spiritual Trust v. United States,  910  F.2d  240,  245
(5th Cir. 1990)).  The court  went  on  to  list  a  number  of  factors  typically  considered  when
determining whether an entity is the alter ego of a corporation, noting that resolution of the  issue
is based on the totality of the circumstances.  Stuart v. Spademan, 772 F.2d  1185,  1197  (5th  Cir.
1985).
      The district court then set forth the evidence that plaintiffs presented to show the  alter-ego
relationship:
      (1)   [KS] and [Gruppe] are both 100% owned by Hans Mueller.
      (2)   In 1989, [KS] held itself out as the owner and licensor of the ‘562 patent but in July of
           1990, [Gruppe] held itself out as the owner and licensor, although legal  title  remained
           at all times in Hans Mueller.
      (3)   The German defendants actively participated in and were represented by  counsel  in  this
           litigation throughout its history, and all defendants, German and domestic, used the term
           “Kanal-Mueller” to identify both the German  defendants  [KS]  and  the  German  licensor
           [Gruppe].


District Court Opinion, slip op. at 44.
      The district court concluded that “[t]he evidence does not show that either  [KS]  or  [Gruppe]
owned stock in the other at any relevant time.  Nor did Insituform present any proof  that  [KS]  and
[Gruppe] failed to follow separate corporate formalities.  In fact, Insituform does  not  submit  any
evidence relevant to the [Stuart] factors listed above.  Absent  such  proof,  [KS]  cannot  be  held
liable as the alter ego of [Gruppe].”  Id. at 45.  Thus, the district court essentially pointed to  a
failure of proof on the part of plaintiffs to show that KS was the alter ego of Gruppe.
      The district court accurately stated the law with respect to plaintiffs’ alter  ego  theory  of
induced infringement.  Moreover, although plaintiffs attempt to  characterize  the  district  court’s
ruling as an error of law, they do not tell us exactly what legal error the district court  comitted.
 For that reason, and because we discern no legal error, we are left to review the  district  court’s
factual findings.
      The district court accurately summarized the totality  of  plaintiffs’  evidence.   On  appeal,
plaintiffs appear to merely reargue their version  of  the  facts.   Indeed,  plaintiffs  praise  the
district court for “making no reference whatsoever” to  allegedly  inadmissible  submissions  by  KS.
Given the highly deferential standard of review, we  do  not  disturb  either  the  district  court’s
finding that plaintiffs essentially failed to carry their burden of  proof  or  its  ultimate  ruling
that KS cannot be held liable as the alter ego of Gruppe.
                                              CONCLUSION
   In sum, we decide the issues before us as follows:

      (1)  Because plaintiffs are not barred  from  asserting  infringement  under  the  doctrine  of
equivalents, we affirm the judgment of infringement with respect to
Process 1.
      (2)  We affirm the ruling of the district court  joining  Insituform  Netherlands  as  a  party
plaintiff.
      (3)  We affirm the ruling of the district court joining Giulio Catallo as a party defendant.
      (4)  We affirm the ruling of  the  district  court  with  respect  to  CAT’s  and  Firstliner’s
inducement of infringement, as well as its ruling with  respect  to  the  extent  to  which  CAT  and
Firstliner instructed their licensees to use infringing Process 1.
      (5)  We vacate the outstanding award of damages and remand to the  district  court  for  (i)  a
determination of the factual issue of when  defendants  stopped  using  Process  1  and  began  using
Process 2, and (ii) a calculation of the quantum of damages based upon that determination.
      (6)   We  vacate  the  district  court’s  finding  of  willful  infringement  and  remand   for
reconsideration in light of our en banc decision in Knorr-Bremse.
      (7)  On plaintiffs’ cross-appeal, we affirm the ruling of the district court declining to  hold
KS vicariously liable to plaintiffs under an alter-ego theory of induced infringement.
                                                COSTS
      Each party shall bear its own costs.


                           AFFIRMED-IN-PART, VACATED-IN-PART, and REMANDED

                        United States Court of Appeals for the Federal Circuit


                                           99-1584, 00-1005

                                    INSITUFORM TECHNOLOGIES, INC.,
                                    INSITUFORM (NETHERLANDS) B.V.,
                                   and INSITUFORM GULF SOUTH, INC.,

                                     Plaintiffs-Cross Appellants,

                                                  v.

                                        CAT CONTRACTING, INC.,
                             FIRSTLINER U.S.A., INC., and GIULIO CATALLO,

                                             Defendants-Appellants,


                                  and


                                 MICHIGAN SEWER CONSTRUCTION COMPANY,

                                                          Defendant-Appellant,

                                                 and

                             KANAL SANIERUNG HANS MUELLER GmbH & CO. KG,

                                             Defendant-Appellee.



Before MAYER, Chief Judge, MICHEL, and SCHALL, Circuit Judges.

PER CURIAM
                                                ORDER
      The Supreme Court vacated the judgment in this  case,  Insituform  Technologies,  Inc.  v.  CAT
Contracting, Inc., 10 Fed. Appx. 871 (Fed. Cir. 2001) (non-precedential decision), and  remanded  the
case to this court on June 3, 2002, “for further consideration in light of Festo  Corp.  v.  Shoketsu
Kinzoku Kogyo Kabushiki Co.”  Insituform Techs.,  Inc.  v.  CAT  Contracting,  Inc.,  535  U.S.  1108
(2002).  Following the Supreme Court’s decision in Festo, this court issued a second  en  banc  Festo
decision.  See Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359 (Fed.  Cir.  2003).
Following that decision, we requested that the parties submit briefs addressing the  consequences  of
both the Supreme Court’s decision in Festo and this court’s subsequent  en  banc  decision  for  this
case.
      After considering the parties’ submissions, we  vacated  the  judgment  of  the  United  States
District Court for the Southern District of Texas awarding damages to plaintiffs for infringement  of
United States Patent No. 4,366,012, Insituform Techs., Inc. v. Cat Contracting, Inc., No.  H-90-1690,
slip op. (S.D. Tex. Aug. 31, 1999), and remanded the case for further proceedings  in  light  of  the
Festo cases.  Insituform Techs., Inc. v. CAT Contracting, Inc., 87 Fed. Appx. 180  (Fed.  Cir.  2004)
(nonprecedential order).  After considering the subsequent Petition for Rehearing  and  Response,  we
conclude that the case may be decided on the merits based on the record now before us.
      Accordingly,
      IT IS ORDERED THAT
      (1)  The Petition for Rehearing is granted.
      (2)  The Order vacating the district court’s judgment and remanding for further proceedings  is
hereby withdrawn and the decision attached to this Order is substituted in its place.
                                             FOR THE COURT

_____________________                        _________________________
                 Date                              Jan Horbaly
                                              Clerk
-----------------------
      [1]   The district court ruled that neither Insituform  Gulf  nor  ITI  had  standing  to  sue.
Plaintiffs do not appeal that ruling.
      [2]   In Insituform II, we referred to KS as “KM.”
      [3]   Firstliner’s Process 2 is no longer before us, it having been determined that it does not
infringe claim 1 either literally or under the doctrine of equivalents.
      [4]   As noted above, Insituform North America, Inc. is no longer a party to the suit.
      [5]   Because we affirm the district court’s ruling that Insituform  Netherlands  was  properly
joined as a party, we need not address plaintiffs’ additional argument on appeal  related  to  adding
Insituform North American, Inc. as a party.
      [6]   At that time, the court made no specific finding regarding the actual date of the switch
as both Process 1 and 2 were found to be infringing.

