  United States Court of Appeals
      for the Federal Circuit
             __________________________

              (Interference No. 105,642)
   ELIYAHOU HARARI, ROBERT D. NORMAN,
         AND SANJAY MEHROTRA,
                Appellants
                          v.
    ROGER LEE AND FERNANDO GONZALEZ,
                 Appellees.
             __________________________

                     2010-1075
             __________________________

    Appeal from the United States Patent and Trademark
Office, Board of Patent Appeals and Interferences.
                __________________________

              (Interference No. 105,645)
   ELIYAHOU HARARI, ROBERT D. NORMAN,
         AND SANJAY MEHROTRA,
                Appellants,
                          v.
    ANDREI MIHNEA, JEFFREY KESSENICH,
             AND CHUN CHEN,
                 Appellees.
             __________________________

                      2010-1076
HARARI   v. LEE                                          2


                  __________________________

    Appeal from the United States Patent and Trademark
Office, Board of Patent Appeals and Interferences.
               ___________________________

                  Decided: September 1, 2011
                  ___________________________

    WILLIAM A. BIRDWELL, Davis Wright Tremaine, LLP,
of Portland, Oregon, argued for appellants. With him on
the brief were TIMOTHY R. VOLPERT and SCOTT E.
WARNICK.

    MEGAN S. WOODWORTH, Dickstein Shapiro LLP, of
Washington, DC, argued for appellees. With her on the
brief were ERIC OLIVER and THOMAS J. D’AMICO.
               __________________________

  Before PROST, MOORE, and O’MALLEY, Circuit Judges.
MOORE, Circuit Judge.
    Eliyahou Harari et al. (Harari) appeals separate deci-
sions of the Board of Patent Appeals and Interferences
(Board) in two interferences involving Harari’s U.S.
Patent Application No. 09/056,398 (’398 application) and
several patents assigned to Micron Technology, Inc.
(Micron). 1 In the Lee interference, the Board entered
judgment against Harari on Count 1 of the interference
(Harari’s corresponding claims are 63-66) on the grounds
that there was no written description support for Harari’s
claims in the specification as filed. Harari argued that it
had incorporated by reference its own earlier application,

   1   We will refer to appeal 2010-1075 as Lee, and ap-
peal 2010-1076 as Mihnea.
3                                             HARARI   v. LEE


U.S. Patent Application No. 07/337,579 (’579 application),
and that this application provided the necessary written
description support. The Board held that the ’579 appli-
cation was not incorporated by reference, and that even if
it were, the incorporation was not sufficiently specific in
identifying the material Harari needs from the ’579
application.
     In the Mihnea interference, the Board entered judg-
ment against Harari on Count 1 of the interference (Ha-
rari’s corresponding claims 68, 70, 71, etc.), also on the
grounds that there was no written description support for
Harari’s claims in the specification as filed because the
necessary portions of the ’579 application were not incor-
porated by reference. The Board in Mihnea also con-
cluded that even if the entire ’579 application were
incorporated, Micron had shown that some of the claims
at issue still lacked written description support.
    There was an intervening decision from this court on
the incorporation by reference of this patent, Harari v.
Hollmer, 602 F.3d 1348, 1351 (Fed. Cir. 2010). In light of
that decision, and after thorough review of the applica-
tions, we conclude that the Board erred in its analysis
regarding the incorporation by reference of the ’579
application. The Board also erred in its claim construc-
tion in Lee. Under the proper claim construction, in light
of the Board’s factual findings, we affirm the Board’s
judgment that Harari’s claims in Lee lack written descrip-
tion support. In Mihnea, however, we vacate and remand
the Board’s judgment for determination of unresolved
factual issues.
                      BACKGROUND
    Harari’s ’398 application descends through a chain of
continuations and a divisional from U.S. Patent Applica-
tion No. 07/337,566 (the ’566 application). Harari filed
HARARI   v. LEE                                           4


the ’398 application as a photocopy of the original ’566
application along with a preliminary amendment cancel-
ing the ’566 application’s claims and adding new claims
that it stated “are substantial copies” of claims in Lee’s
U.S. Patent No. 5,619,454 (the Lee patent). Lee J.A. 657.
Harari later added more claims it asserted “are either
exact copies or near exact copies” of claims in Mihnea’s
U.S. Patent Nos. 6,426,898 and 6,493,280 (the Mihnea
patents). Mihnea J.A. 917.
    On June 23, 2008, the United States Patent and
Trademark Office (USPTO) declared Patent Interference
No. 105,642 against Lee. Lee J.A. 54-55. Several weeks
later, the USPTO declared Patent Interference No.
105,645 between Harari and Mihnea. Mihnea J.A. 52-53.
In both interferences, Micron – the real party in interest
representing Lee and Mihnea – filed threshold motions to
dismiss, alleging that Harari’s involved claims were
unpatentable for lack of written description support.
Harari asserted that the allegedly incorporated ’579
application supported the involved claims. Micron, how-
ever, argued that Harari’s ’398 application failed to incor-
porate the ’579 application by reference.
    Micron did not dispute that Harari’s original ’566 ap-
plication properly identified the ’579 application as “co-
pending U.S. patent application[] . . . entitled ‘Multistate
EEprom Read and Write Circuits and Techniques,’ filed
on the same day as the present application, by Sanjay
Mehrotra and Dr. Eliyahou Harari.” Lee J.A. 695 (em-
phasis added). Because the ’566 and ’579 applications
were filed on the same day and were not yet assigned
serial numbers, referencing the ’579 application by inven-
torship and title was appropriate.
    Micron argued instead that, even though it was a pho-
tocopy of the ’566 application, Harari’s later-filed ’398
5                                              HARARI   v. LEE


application failed to identify the ’579 application. Micron
asserted that the phrase “the same day as the present
application” should be interpreted to mean the same day
that the ’398 application was filed, not the original ’566
application’s filing date. Both Board panels agreed, and
determined that the allegedly incorporated material was
instead new matter. Because Harari relied on this mate-
rial to support the claims at issue, the two Board panels
held that Harari’s claims lacked written description
support.
    The Board panels further concluded that even if the
’398 application adequately identified the ’579 application
as the target application, it failed to identify with suffi-
cient specificity the portions of the ’579 application relied
upon by Harari. The Mihnea Board also held that even if
the entire ’579 application was incorporated, Micron had
shown that certain claims, the “offset erase verify bias”
claims, still lacked written description support. In con-
trast, the Lee Board concluded that Micron had failed to
show that the claims at issue lacked written description
support if the entire ’579 application was incorporated by
reference. The two Board panels thus granted Micron’s
threshold motions to dismiss and entered judgment on
priority against Harari. Harari appeals both cases, and
we have jurisdiction under 28 U.S.C. § 1295(a)(4)(A) and
35 U.S.C. § 141.
    After the Board panels entered judgment for Micron
in the Lee and Mihnea interferences, we decided Harari v.
Hollmer, which involved another Harari application
similarly descended from the ’566 application. 602 F.3d
at 1350. Like the ’398 application at issue, the Harari
application in Hollmer was filed as a photocopy of the
original ’566 application along with a preliminary
amendment canceling the photocopied claims, adding new
claims, updating the cross-references to related applica-
HARARI   v. LEE                                          6


tions, and inserting text and drawings from the incorpo-
rated ’579 application. Id. at 1350-51. In Hollmer, we
held that the same incorporation language that is before
us in Lee and Mihnea was sufficient to identify the ’579
application. Id. at 1351-52. Micron now concedes that,
under Hollmer, Harari’s ’398 application adequately
identified the ’579 application for incorporation. The
parties still dispute, however, how much of the ’579
application was incorporated.
                            DISCUSSION
                  I.   Incorporation by Reference
    Whether and to what extent a patent application in-
corporates material by reference is a question of law we
review de novo. Hollmer, 602 F.3d at 1351. In making
that determination, the standard is whether one reasona-
bly skilled in the art would understand the application as
describing with sufficient particularity the material to be
incorporated. Zenon Envtl., Inc. v. U.S. Filter Corp., 506
F.3d 1370, 1378-79 (Fed. Cir. 2007).
     Harari argues that in Hollmer we held that the entire
’579 application was incorporated by reference. We
disagree. The parties in Hollmer disputed only whether
the incorporation language adequately identified the ’579
application, and we had no occasion to determine whether
all or only some of the application was incorporated. 602
F.3d at 1352 & n.1. Accordingly, Hollmer holds only that
the photocopied incorporation language is sufficient to
identify the ’579 application when considered by a “rea-
sonable examiner in light of the documents presented.”
Id. at 1353. Hollmer did not address the extent of the
incorporation. Because the parties dispute the extent of
incorporation, we must now perform that analysis.
7                                               HARARI   v. LEE


    The parties’ dispute focuses on two passages in the
’398 application, i.e., the photocopy of the ’566 application.
The application first discusses incorporation of the ’579
application and another application which is not at issue
here:
    Optimized erase implementations have been dis-
    closed in two copending U.S. patent applications.
    They are copending U.S. patent applications, Se-
    rial No. 204,175, filed June 8, 1988, by Dr. Eliya-
    hou Harari and one entitled “Multistate EEprom
    Read and Write Circuits and Techniques,” filed on
    the same day as the present application, by San-
    jay Mehrotra and Dr. Eliyahou Harari. The dis-
    closures of the two applications are hereby
    incorporate[d] by reference. The Flash EEprom
    cells are erased by applying a pulse of erasing
    voltage followed by a read to verify if the cells are
    erased to the “erased” state. If not, further pulsing
    and verifying are repeated . . . .
Lee J.A. 695 (emphasis added). In a later paragraph, the
application again discusses the two applications, but uses
different and arguably narrower language:
    Optimized implementations of write operation for
    Flash EEprom device have been disclosed in two
    previously cited co-pending U.S. patent applica-
    tions, Serial No. 204,175, and one entitled "Multi-
    State EEprom Read and Write Circuits and Tech-
    niques.” Relevant portions of the disclosures are
    hereby incorporated by reference. Briefly, during
    the write cycle, the controller applies a pulse of
    programming (or writing) voltages. This is fol-
    lowed by a verify read to determine if all the bits
    have been programmed properly. If the bits did
HARARI   v. LEE                                            8


   not verify, the controller       repeats   the   pro-
   gram/verify cycle . . . .
Lee J.A. 706 (emphasis added).
    Harari argues that the first incorporation statement
plainly and unambiguously incorporates the entire ’579
disclosure. According to Harari, the second incorporation
statement shows that the inventors knew how to incorpo-
rate only a portion of the ’579 application and chose not to
do so in the first statement. Harari further argues that
there is no need to use such words as “in its entirety” to
indicate that the entire reference is incorporated. Micron
responds that the Board correctly determined that the
above-quoted language fails to clearly indicate with
detailed particularity that Harari intended to incorporate
all of the ’579 application. Instead, Micron argues, the
incorporation language when read in context indicates
that Harari intended to incorporate only the optimized
erase and optimized write implementations as described
in the short passages following the incorporation lan-
guage. Micron also argues that the second incorporation
statement is superfluous if the first one actually incorpo-
rated the entire ’579 application.
    We agree with Harari that the first incorporation pas-
sage incorporates the entire disclosures of the two appli-
cations rather than just the portions describing optimized
erase implementations. The Board is certainly correct
that the incorporation here occurred during a discussion
of the erase implementations. We nonetheless conclude
that the entire ’579 application disclosure was incorpo-
rated by the broad and unequivocal language: “The
disclosures of the two applications are hereby incorpo-
rate[d] by reference.” We contrast the incorporation
language used here, “the disclosures,” with the incorpora-
tion language used later in the same specification, “rele-
9                                              HARARI   v. LEE


vant portions of the disclosures.” When the drafter in-
tended to incorporate only a portion it did so expressly.
While it may seem redundant, nothing prevents a patent
drafter from later incorporating again certain “relevant
portions” of an application so as to direct the reader to the
exact portion of the incorporated document the drafter
believes relevant. In the context of this specification and
the language used, we conclude that the ’398 application
incorporates the entire disclosure of the ’579 application.
     Even if the ’398 application was limited to the incor-
poration of the optimized erase and optimized write
implementations of the ’579 application, we conclude that
all of the sections at issue – the reprogramming feature
and the indirect read implementation – are part of the
disclosed optimized erase and optimized write. In Lee, the
Board held that the reprogramming feature was not part
of the optimized erase and optimize write implementa-
tions. The Board defined the optimized erase and write
implementations to include only the erase/verify and the
program/verify cycles summarized in brief passages
following the incorporation language. The Board rea-
soned that because “[t]he reprogramming of an erased cell
is described in the disclosure of the ’579 application as
being drawn to a ‘different aspect’ and ‘different feature’
of the disclosed invention,” the reprogramming feature is
“something other than the substantive material properly
identified for incorporation by reference.” Lee J.A. 32-33
(misquoting the ’579 application by twice substituting the
word “different” for “another”).
    On appeal, Micron repeats the Lee Board’s reasoning,
and further asserts that reprogramming occurs only after
a memory cell has been erased. Harari disagrees, and
argues that optimized erase and write necessarily include
the reprogramming feature. We agree with Harari. The
reprogramming feature is part of the optimized erase and
HARARI   v. LEE                                             10


optimized write implementations described in the ’579
application and is therefore incorporated into the ’398
application. As a preliminary matter, the fact that the
specification refers to the reprogramming as “another
aspect” or “another feature” of the present invention is not
dispositive of the inquiry. First, we note that the repro-
gramming discussion cited by the Board appears in the
section of the specification entitled: “Read Circuits and
Techniques Using Reference Cells.” The summary of the
invention portion of the patent explains that the inven-
tion is “improvements in EEprom array read and write
circuits and techniques in order to provide multiple
threshold levels that allow accurate reading and writing
of more than two distinct states within each memory cell
over an extended lifetime of the memory cells, so that
more than one bit may be reliably stored in each cell.”
The reprogramming is part of the read circuits and tech-
niques. As the reprogramming discussion cited by the
Board explains, the reprogramming “provides a uniform
starting point for subsequent programming of the cells.”
It makes sure that all of the erased cells are brought to
the same state – the ground state. Harari’s expert ex-
plained that after cells are put into an “erased” state, they
are reprogrammed to the ground state to “‘provide[] a
uniform starting point for subsequent programming of the
cells.’” Lee J.A. 766 (quoting the ’579 application repro-
duced at Lee J.A. 346). As the expert explained, this
helps to ensure that the cells undergo the same number of
cycles, which helps improve cell accuracy and reliability.
Lee J.A. 766-67. The expert concluded, “Harari’s ‘re-
programming’ technique completes the erase sequence, in
order to initialize all cells to the same ‘ground’ level before
data programming commences.” Lee J.A. 795 (emphasis
in original). Therefore, the reprogramming feature is part
of the optimized erase implementation disclosed in the
11                                              HARARI   v. LEE


’579 application and therefore was incorporated by refer-
ence.
     In Mihnea, the Board addressed the incorporation of
material describing adjusting the bias applied to a refer-
ence cell, which is a part of the ’579 application’s disclosed
indirect read implementation.          The ’579 application
describes two read implementations that compare a
memory cell value to the threshold values stored in local
reference cells. Local reference cells are located in each
sector along with the sector’s memory cells and store
copies of the thresholds stored in master reference cells.
Because the local reference cells are subject to the same
conditions and number of cycles as their associated mem-
ory cells, using local reference cells as a basis for compari-
son automatically compensates for changes in cell
performance over time or due to local conditions. Lee J.A.
340, 343-44. The first described read implementation
directly compares the memory cell’s stored value to a
threshold stored in a local reference cell. Lee J.A. 342.
The second read embodiment indirectly compares the
memory cell to the threshold in the local reference cell.
The memory cell is compared to the master reference
cell’s copy of the threshold that has been biased by a value
reflecting the local reference cell’s copy of the threshold.
Lee J.A. 343-45. “[E]very time a sector is read, the master
reference cells [holding the thresholds] are re-biased
relative to the local reference cells, and used for reading
the memory cells in the sector.” Lee J.A. 343-45. Thus,
when using this indirect read implementation, “local
reference cells (which track threshold deviations of the
addressed cells) are used to effectively readjust the
breakpoint thresholds of the master reference cells.” Lee
J.A. 343-44.
    The Mihnea Board determined that the incorporation
language failed to sufficiently identify the material re-
HARARI   v. LEE                                          12


garding adjusting the bias applied to a reference cell.
Mihnea J.A. 35. The Board reasoned that adjusting the
bias is part of the indirect read implementation, and that
only the direct read implementation is used to verify a
cell’s status during the erase/verify and program/verify
cycles. The Board relied on a portion of the ’579 applica-
tion that states that the “local reference cells are used
directly to read or program/erase verify the sector’s
memory cells,” while in the indirect read embodiment,
“‘the local reference cells are used indirectly to read the
addressed memory cells.’” Mihnea J.A. 33-34 (quoting the
’579 application as reproduced at Lee J.A. 342) (emphases
added by Board).
    On appeal, Micron repeats the Board’s reasoning and
further argues that adjusting the bias applied to a master
reference cell is performed only to track and compensate
for changes to the memory cells over time, and is there-
fore of little use in the “micro- or nano-seconds between
the erasure of the cell and its verification.” Mihnea
Appellee’s Br. 38-39. Harari responds that verifying is
performed by either of the two read embodiments dis-
closed in the ’579 application.
    We again agree with Harari. The ’579 application ex-
plains that both read embodiments are used to verify. It
unambiguously states that local reference cells “are used
directly or indirectly to erase verify, program verify or
read the sector’s addressed memory cells.” Lee J.A. 342.
Furthermore, immediately after describing the indirect
read implementation, the ’579 application explains that
“the read circuits and operation described are also em-
ployed in the programming and erasing of the memory
cells, particularly in the verifying part of the operation.”
Lee J.A. 345 (emphases added). The ’579 application itself
thus expressly states that the described read circuits, the
very ones at issue, are part of the verifying process. Even
13                                             HARARI   v. LEE


though Micron argues that adjusting the bias for each
read is unnecessary, the ’579 application explains that
“every time a sector is read, the master reference cells are
re-biased relative to the local reference cells.” Lee J.A.
345. Micron also repeats its arguments from Lee regard-
ing the reprogramming feature, which are similarly
unavailing in Mihnea. Accordingly, we conclude that the
material at issue in Mihnea was incorporated as part of
the described optimized erase and write implementations.
    In summary, we conclude that the ’579 application
was incorporated in its entirety, and that, moreover, the
portions of the ’579 application that Harari argues pro-
vide the written description support for its claims are part
of the optimized erase and write implementations.
        II. Harari v. Mihnea: Written Description
    The claims at issue can be divided into two categories:
those with an “offset erase verify bias” limitation and
those without. In Mihnea, the Board held that if the ’579
application was incorporated by reference, the claims
without an “offset erase verify bias” limitation, such as
claim 68, were supported by the specification. On appeal,
Micron does not dispute that those claims – those not
reciting the offset erase verify bias limitation – are sup-
ported if the disputed portions of ’579 application were
indeed incorporated by reference. With regard to those
claims reciting an “offset erase verify bias” limitation, the
Board held that they lacked written description support
even if all of the ’579 application was incorporated by
reference. Harari disputes this determination.
    Harari’s claim 70 illustrates the offset erase verify
bias claims at issue here:
     70. The method of claim 68, wherein said erasing
     step comprises:
HARARI   v. LEE                                          14


        offsetting an erase verify bias used to deter-
   mine if the flash memory cells are in first of said
   at least two data states;
     applying at least one erase pulse to each flash
   memory cell;
       determining whether contents of the cells are
   erased using the offset erase verify bias; and
       repeating said applying and determining steps
   until all of the cells are erased to a state other
   than one of at least two data states.
Mihnea J.A. 757, 909-18 (emphases added). The applying,
determining, and repeating steps of claim 70 recite an
erase/verify cycle at least similar to that described in the
’579 application. Memory cells are alternately pulsed
with an erase voltage and then verified by comparing to a
threshold to see if they are in a non-data state, which
Harari’s specification calls the “erased” state (which is
similar to the “over-erased” condition described in
Mihnea). See Lee J.A. 345-46; 695-96; Mihnea patent
col.6 l.20 - col.7 l.61. 2
    In Mihnea, the Board’s determination turned on
whether the second read implementation could be used to
verify the cells. The Board’s reasoning echoed its incorpo-
ration by reference reasoning: the indirect read – along
with its description of adjusting the bias of master refer-
ence cells – applied only to the read operation and not the
verify operation. Mihnea J.A. 36. Thus, the Board con-
cluded, even assuming the indirect read implementation
was incorporated, Harari could not rely on it to support
the erase verify bias claims. Mihnea J.A. 36.


   2    All citations to a Mihnea patent specification are
to U.S. Patent No. 6,426,898.
15                                               HARARI   v. LEE


    We disagree. As we described above with respect to
incorporation by reference, the ’579 application describes
using both the indirect and the direct read implementa-
tions to perform the verify portion of the erase/verify and
write/verify cycles. The application clearly states that
local reference cells “are used directly or indirectly to
erase verify, program verify or read the sector’s addressed
memory cells.” Lee J.A. 342. Furthermore, immediately
after describing the indirect read implementation, the
’579 application explains that “the read circuits and
operation described are also employed in the program-
ming and erasing of the memory cells, particularly in the
verifying part of the operation.” Lee J.A. 345.
    Micron also argues that Harari’s offset erase verify
bias claims are not supported even if the indirect read
may be used to verify. Specifically, Micron argues that
Harari’s applications never discuss adjusting the thresh-
old of a data state (i.e., offsetting an erase verify bias that
is used to determine if a cell is in the data state) to erase
a memory cell through the data state into a non-data
state as the claims require. Micron asserts that Harari
merely adjusts thresholds stored in master reference cells
to reflect the values stored in local reference cells. Ac-
cording to Micron, this ensures that cells are erased to the
desired state despite memory cell degradation over time.
Mihnea Appellee’s Br. 44. Harari, pointing to the ’579
application’s discussion of “erase margining schemes,”
argues that the application describes bias offsets that are
used to erase the cell deep into the erased state. Mihnea
Reply Br. 25.
    Mihnea’s specification explains that during erase veri-
fying, the memory cell’s value is compared to a threshold
called an erase verify bias to determine if the cell is in the
lowest data state, which it calls the erased state and
corresponds to Harari’s ground state. By changing that
HARARI   v. LEE                                             16


threshold by some amount, i.e., by offsetting the erase
verify bias, the erase/verify cycle will drive the cell’s value
down until the cell is in a non-data state that Mihnea
calls the over-erased state and Harari calls the erased
state. In other words, Mihnea applies erase pulses until
the cell is verified to be past a new threshold value equal
to the erase verify bias including the offset. Mihnea
patent col.8 ll.25-50.
     In contrast, Harari’s ’579 application describes an in-
direct read implementation where the memory cell is
compared to a threshold stored in a master reference cell
that has been biased by a value reflecting another copy of
the same threshold stored in a local reference cell. Lee
J.A. 343-45 (“[E]very time a sector is read, the master
reference cells [holding the thresholds] are re-biased
relative to the local reference cells, and used for reading
the memory cells in the sector.”). Thus, “local reference
cells (which track threshold deviations of the addressed
cells) are used to effectively readjust the breakpoint
thresholds of the master reference cells.” Lee J.A. 343-44.
Because the local reference cells are subject to the same
conditions and number of cycles as their associated mem-
ory cells, this automatically compensates for changes in
cell performance over time or due to local conditions. Lee
J.A. 343-44.
    The ’579 application also discusses margining, a pro-
cedure that can be used to help compensate for charge
retention problems in memory cells. Over time, the stored
charge in a memory cell’s floating gate may diminish
through leakage, which could cause the cell’s voltage to
drop below a threshold into the next lower state. To
compensate, the ’579 application discusses putting the
memory cell further into the desired state by erasing and
programming memory cells past the desired state’s
threshold by a safety margin. Lee J.A. 335, 351-52. For
17                                             HARARI   v. LEE


example, when performing the verification in the
erase/verify cycle, a variable voltage is adjusted down-
ward by an amount corresponding to the safety margin,
causing the cell to be pulsed further into the desired state.
Lee J.A. 352.
     Thus, the dispute is whether the ’579 application’s de-
scription of margining and biasing a master reference cell
relative to a local reference cell provides written descrip-
tion support for the offset erase verify bias claims. We
decline to resolve this technical, fact-intensive question in
the first instance, and instead vacate and remand to the
Board for further proceedings consistent with this opin-
ion.
                      III. Harari v. Lee
     In Lee, the Board determined that, if all of the ’579
application was incorporated by reference, then Micron
failed to show that Harari’s claims 63-66 lack written
description support.    Harari’s independent claim 63,
which Harari asserted is a “substantial cop[y]” of Lee’s
claim 1, recites:
     A method of treating healing at least one over-
     erased EEprom memory cell, comprising:
         a) accessing a number of control gates and ac-
     cessing a bit digit line, thereby activating a said
     number of memory cells, each of said memory cells
     having a source, a drain, and a control gate;
         b) subsequent to accessing said bit digit line,
     sensing the presence of at least one over erased
     activated cell from said number of memory cells
     that is erased to a state other than one of at least
     two data states; and
HARARI   v. LEE                                             18


        c) subsequent to sensing the presence of said
   over erased cell, applying a first voltage to said bit
   digit line, a second voltage to said control gate of
   at least said over-erased cell, and a third voltage
   to said source of at least said over-erased cell, said
   first and second voltages being higher than said
   third voltage.
Lee J.A. 657, 759; Lee patent claim 1. 3 The Board deter-
mined that the broadest reasonable construction of Ha-
rari’s claim 63 encompassed accessing more than one bit
line to activate multiple memory cells. Lee J.A. 35-36.
The Board reasoned that nothing in the claim language
precluded such a meaning, and viewed using a single bit
line as a species within the genus of using one or more bit
lines. Lee J.A. 36-37. The Board concluded that Micron
failed to show that Harari’s disclosure of accessing multi-
ple bit lines does not provide written description support.
Lee J.A. 37.
    As an alternative ground for affirming, Micron argues
on appeal that the Board’s claim construction is incorrect,
and that under the correct claim construction Harari’s
claims lack written description support. According to
Micron, the plain language of Harari’s claim 63 requires
that multiple memory cells are activated by accessing
their control gates and a single bit line. Harari replies
that because “a bit line” means one or more bit lines, the
Board’s claim construction is correct.
                  A. Claim Construction

   Claim construction is a matter of law we review de
novo. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448,
1455-56 (Fed. Cir. 1998) (en banc). Because this is an

   3     The strikethroughs and underlines reflect Ha-
rari’s edits to Lee’s claim.
19                                            HARARI   v. LEE


interference and Harari substantially copied Lee claim 1,
we give the claim its broadest reasonable construction in
light of the Lee patent specification. Agilent Techs., Inc.
v. Affymetrix, Inc., 567 F.3d 1366, 1375 (Fed. Cir. 2009)
(discussing the rule of In re Spina, 975 F.2d 854, 856
(Fed. Cir. 1992)). To satisfy the written description
requirement, the properly construed claim must be sup-
ported by Harari’s specification. Id. at 1378-79. Micron,
as the moving party, bears the burden of proof to demon-
strate that Harari’s claims as properly construed lack
written description support. See 37 C.F.R. § 41.121(b).
Compliance with the written description requirement is a
question of fact that we review under the substantial
evidence standard. Chen v. Bouchard, 347 F.3d 1299,
1304 (Fed. Cir. 2003).
     Harari’s arguments rely on our rule that the indefi-
nite article “a” means “‘one or more’ in open-ended claims
containing the transitional phrase ‘comprising.’” Lee
Appellant’s Br. 21 (quoting Baldwin Graphic Sys., Inc. v.
Siebert, Inc., 512 F.3d 1338, 1342 (Fed. Cir. 2008)). In
Baldwin, we construed a claim reciting a system compris-
ing “a pre-soaked fabric roll” and a “means for locating
said fabric roll.” 512 F.3d at 1340. We concluded that the
claim encompassed systems with more than one fabric
roll. Id. at 1343.
    Baldwin, however, does not set a hard and fast rule
that “a” always means one or more than one. Instead, we
read the limitation in light of the claim and specification
to discern its meaning. Insituform Techs., Inc. v. Cat
Contracting, Inc., 99 F.3d 1098, 1105-06 (Fed. Cir. 1996)
(analyzing the “claims, specification and file history” to
determine that “a vacuum cup” means one and only one
vacuum cup). When the claim language and specification
indicate that “a” means one and only one, it is appropriate
HARARI   v. LEE                                           20


to construe it as such even in the context of an open-ended
“comprising” claim.
    In this case, the relevant independent claim does not
recite a memory device having “a” bit line. Instead, it
recites a method comprising accessing a number of control
gates and a bit line to activate a number of cells. The
plain language of the claim clearly indicates that only a
single bit line is used when accessing a number of cells.
     As in Insituform, nothing in the text of Harari’s claim
63 suggests accessing more than one bit line when acti-
vating the number of memory cells. For example, step a)
expressly distinguishes between the singular and plural
by reciting “accessing a number of control gates” while
“accessing a bit line” to activate “a number of memory
cells.” Step b) further reinforces the difference between
singular and plural by reciting “subsequent to accessing
said bit line, sensing the presence of at least one activated
cell.” And finally, step c) again distinguishes between
singular and plural by applying “a first voltage to said bit
line,” while applying other voltages to the source and
control gate of “at least said erased cell.”
    We also note that Lee’s claim 1 recites “accessing a
number of control gates and accessing a digit line, thereby
activating said number of memory cells.” Lee patent,
claim 1 (emphasis added). Lee’s claim 1 expressly links
the number of activated cells to the number of control
gates accessed in the row corresponding to the accessed
digit 4 line. Therefore, the number of memory cells acti-
vated must be the same as the number of control gates
accessed. The Lee patent explains that the drains of the
cells in one row are all connected to a single digit line. A
subset of the cells in the row can be accessed by applying

    4   Lee’s digit lines are called bit lines in Harari’s
’398 application.
21                                              HARARI   v. LEE


a voltage to the control gates of only some of the cells in
the row via their control lines, which are connected to the
cells in columns. Lee patent col.3 ll.33-40. Lee further
explains that if any one or more of the cells in the row are
over-erased, the drain voltage (VD) sensed at that row’s
digit line will be positive. Id. col.3 ll.49-50. If only some
of the cells in the row are selected, a positive drain volt-
age on the digit line reveals if any of the selected cells are
over-erased. The Lee patent also discloses, but does not
recite in claim 1, finding which cell of the selected cells is
over-erased. Id. col.3 l.51-64. Lee explains that an over-
erased cell can be “healed” by applying a healing voltage
for a short time to its drain via the digit line and to its
control gate while applying 0 volts to its source. Id. col.3
l.65 - col.4 l.18. Lee does not consider accessing more
than one digit line at a time but instead describes travers-
ing through memory, digit line by digit line. Id. col.3
ll.31-32, col.4 ll.15-20; FIG. 4. The number of cells acti-
vated corresponds to the number of control gates accessed.
Accordingly, we conclude that the correct and only rea-
sonable construction of the claim terms “a bit line” and
“said bit line” as read in light of the Lee specification is
that Harari’s claim 63 requires that a single bit line
activates multiple memory cells.
                  B. Written Description

    This written description decision turned almost en-
tirely on the claim construction. As Micron explains, the
’579 application discloses selecting a single memory cell
by row and column. In short, there is no disclosure in
Harari of a single bit line activating multiple memory
cells.
    On appeal, Harari argues that the ’579 specification
describes selecting a plurality of bit lines simultaneously
using a drain multiplexer. Lee Appellant’s Br. 36 (citing
HARARI   v. LEE                                          22


Lee J.A. 330). According to Harari, when multiple bit
lines are selected using the drain multiplexer, the bit
lines become electrically connected. The Board, however,
made a factual determination that the ’579 application
does not disclose electrically connecting multiple bit lines
to form one bit line. Lee J.A. 38-39. The Board rejected
Harari’s argument as unsupported by the testimony of
any expert witness. The Board, relying on the testimony
of Micron’s expert, found that the ’579 application does
not disclose electrically connecting multiple bit lines to
form one bit line. We conclude that this fact finding is
supported by substantial evidence.
    On appeal, Harari asserts that Micron’s expert testi-
mony is “squarely contradicted” by the specification, and
thus “is simply not credible on this point.” Lee Appellant’s
Br. 37. We disagree. The Board’s factual finding is
supported by substantial evidence, namely, expert testi-
mony that the ’579 application does not disclose or even
suggest that a plurality of bit lines can be electrically
connected together. Lee J.A. 39, 803. Harari points to no
section of its disclosure explaining that such selecting
electrically connects the bit lines. Moreover, accessing
multiple bit lines simultaneously with a multiplexer is not
accessing a single bit line. Similarly, calling multiple bit
lines a “composite bit line” as Harari does in its briefs
does not make it so. Accordingly, we affirm the Board’s
decision granting Lee’s threshold motion alleging unpat-
entability for lack of written description and its judgment
on priority against Harari.
                       CONCLUSION
    For the foregoing reasons, we vacate and remand
Mihnea for further proceedings, and affirm the Board’s
judgment in Lee.
23                                             HARARI   v. LEE


                   Harari v. Lee, 2010-1075
                         AFFIRMED
                            COSTS
     No costs.
                 Harari v. Mihnea, 2010-1076
                 VACATED AND REMANDED
                            COSTS
     No costs.
