From: Hironori Kitagawa <h_kitagawa2001@yahoo.co.jp>
Date: Tue, 15 Nov 2011 05:29:41 +0000 (+0900)
Subject: Updated the draft for post-proceedings.
X-Git-Url: http://git.osdn.jp/view?a=commitdiff_plain;h=a8ccaef258cd958b4cc629c92a2d58537679a66d;p=luatex-ja%2Fluatexja.git

Updated the draft for post-proceedings.
---

diff --git a/doc/ajt-devel-ltja.tex b/doc/ajt-devel-ltja.tex
index a91f5ac..15be69d 100644
--- a/doc/ajt-devel-ltja.tex
+++ b/doc/ajt-devel-ltja.tex
@@ -16,7 +16,7 @@
 \lstset{basicstyle=\ttfamily\small, width=0.3\textwidth, basewidth=.5em}
 
 \usepackage{mflogo,booktabs}
-\definecolor{gray10}{gray}{0.9}
+\definecolor{grayx}{gray}{0.85}
 
 %%% Verbatim environment
 \usepackage{fancyvrb}
@@ -56,20 +56,23 @@ internal processing methods of \LuaTeX-ja.
 \section{Introduction}
 \subsection{History}
 To typeset Japanese documents with \TeX, ASCII p\TeX~\cite{ptex} has
-been widely used in Japan.  There are other methods---for example, using Omega
-and OTP~\cite{omega}, or with the CJK package---to do so, however,
-these alternative methods did not become a majority. On the one hand,
-p\TeX\ enables us to produce high-quality documents. 
-
-On the other hand, p\TeX\ is left behind from the extensions of \TeX\
+been widely used in Japan.  There are other methods---for example, using
+Omega and OTP~\cite{omega}, or with the CJK package---to do so, however,
+these alternative methods did not become a majority.  The author thinks
+that this is because p\TeX\ enables us to produce high-quality documents
+(e.g.,~supporting vertical typesetting), and the appearance of p\TeX\ is
+earlier than alternatives described above.
+
+However, p\TeX\ has been left behind from the extensions of \TeX\
 such as \eTeX\ and \pdfTeX, and the diffusion of UTF-8 encoding.  In
 recent years, the situation become better, because of developments
 of |ptexenc|~\cite{ptexenc} by Nobuyuki Tsuchimura (\hbox{土村展之}),
 $\varepsilon$-p\TeX~\cite{eptex} by the author,~and up\TeX~\cite{uptex}
 by Takuji Tanaka (田中琢爾). However, continuing this approach, namely, to develop
 an engine extension localized for Japanese, is not wise. This approach
-needs lots of work for \emph{each} engine, and \LuaTeX\ has an ability
-to hook \TeX's internal process by using Lua callbacks.
+needs lots of work for \emph{each} engine, and since \LuaTeX\ has an ability
+to hook \TeX's internal process by using Lua callbacks, the necessity of
+an engine extension is getting smaller.
 
 
 There were several experimental attempts to typeset
@@ -111,7 +114,8 @@ In this point, previous attempts of Japanese typesetting with \LuaTeX\
 
 p\TeX\ has some flexibility of typesetting, by changing internal
      parameters such as |\kanjiskip| or |\prebreakpenalty|, and by using
-     custom JFM (Japanese TFM). 
+     custom JFM (Japanese TFM). Therefore we decided to include these
+     functionality to \LuaTeX-ja.
 
 \item\emph{\LuaTeX-ja isn't mere re-implementation or porting of p\TeX;
      some (technically and/or conceptually) inconvenient features of
@@ -132,7 +136,7 @@ that the materials in this section have good applications.
 This \LuaTeX-ja project is hosted by SourceForge.jp. The official wiki
 is located on
 \url{http://sourceforge.jp/projects/luatex-ja/wiki/FrontPage}.  There is
-no stable version at Oct.\ 11, 2011, however the development source can be
+no stable version at Oct.\ 15, 2011, however the development source can be
 obtained from the git repository.  Members of the project are as follows
 (in random order): Hironori Kitagawa, Kazuki Maeda, Takayuki Yato,
 Yusuke Kuroki, Noriyuki Abe, Munehiro Yamamoto, Tomoaki Honda,
@@ -142,7 +146,7 @@ and~Shuzaburo Saito.
 \section{Major differences with \pTeX}
 In this section, we look at several major differences between p\TeX\
 and our \LuaTeX-ja.  For general information of Japanese typesetting and the
-overview of p\TeX, please see Okumara~\cite{ptexjp}.
+overview of p\TeX, please see Okumura~\cite{ptexjp}.
 
 
 \subsection{Names of Control Sequences}
@@ -153,7 +157,7 @@ primitive |\prebreakpenalty|$\langle\hbox{\it
 char\_code}\rangle$|[=]|$\langle\hbox{\it penalty}\rangle$ in p\TeX\
 sets the amount of penalty inserted before a character whose code is
 $\langle\hbox{\it char\_code}\rangle$ to $\langle\hbox{\it
-penalty}\rangle$, and |\prebreakpenalty|$\langle\hbox{\it
+penalty}\rangle$, and this form |\prebreakpenalty|$\langle\hbox{\it
 char\_code}\rangle$ can be also used for retrieving the value.
 
 Moreover, there are some parameters which values of them at the end of a
@@ -178,13 +182,13 @@ of most parameters in \LuaTeX-ja are summarized into the following
       a string.
 \end{itemize}
 
-\subsection{Line Break after a Japanese Character}
+\subsection{Line-break after a Japanese Character}
 \label{ssec-line} 
 
 Japanese texts can break lines almost everywhere, in contrast with
 alphabetic texts can break lines only between words (or use
 hyphenation). Hence, p\TeX's input processor is modified so that a
-line break after a Japanese character doesn't emit a space. However,
+line-break after a Japanese character doesn't emit a space. However,
 there is no way to customize the input processor of \LuaTeX, other than
 to hack its CWEB-source. All a macro package can do is to modify an input line before
 when \LuaTeX\ begin to process it, inside the |process_input_buffer|
@@ -202,11 +206,11 @@ judgement whether a comment letter will be appended the line is done
 
 Figure~\ref{fig-linebreak} shows an example of this situation; the
 command at the first line marks most of Japanese characters as
-non-Japanese characters. In other words, from that command onward, the
+`non-Japanese characters'. In other words, from that command onward, the
 letter `あ' will be treated as an alphabetic character by
-\LuaTeX-ja. Then, it is natural to occur a space between `あ' and `y' in
+\LuaTeX-ja. Then, it is natural to have a space between `あ' and `y' in
 the output, where the actual output in the figure does not so.  This is
-because `あ' is considered to be a Japanese character by \LuaTeX-ja,
+because `あ' is considered a Japanese character by \LuaTeX-ja,
 when \LuaTeX-ja does a decision whether U+FFFFF will be added to the
 input line~2.
 
@@ -226,7 +230,7 @@ Japanese character.}\label{fig-linebreak}
 Traditionally, most Japanese fonts used in typesetting are not
 proportional, that is, most glyphs have same size (in most cases,
 square-shaped). Hence, it is not rare that the contents of different
-JFMs are totally same, and only differ in their names. For example,
+JFMs are essentially same, and only differ in their names. For example,
 |min10.tfm| and |goth10.tfm|, which are JFMs shipped with p\TeX\ for
 seriffed \emph{mincho} family and sans-seriffed \emph{gothic} family,
 differ their |FAMILY| and |FACE| only. Moreover, |jis.tfm| and
@@ -235,7 +239,8 @@ used in \emph{jsclasses}~\cite{jsclasses} by Haruhiko Okumura (奥村晴彦),
 are totally same as binary files.  Considering this situation, we
 decided to separate `real' fonts and metrics used for them in
 \LuaTeX-ja. Typical declarations of Japanese fonts in the style of plain
-\TeX\ are shown in Figure~\ref{fig-jfdef}.
+\TeX\ are shown in Figure~\ref{fig-jfdef}. We would like to add several
+remarks:
 \begin{itemize}
 \item A control sequence |\jfont| must be used for Japanese fonts, instead of |\font|.
 \item \LuaTeX-ja automatically loads the \emph{luaotfload} package, so
@@ -250,9 +255,9 @@ decided to separate `real' fonts and metrics used for them in
       fonts. When one display a pdf with these fonts, actual fonts which
       will be used for them depend on a pdf reader. 
 \end{itemize}
-The specification of a metric used in \LuaTeX-ja is similar to that of a
-JFM (see \cite{ptexjp}); characters are grouped into several classes,
-the size information of characters are specified for each class, and
+The specification of a metric for \LuaTeX-ja is similar to that of a JFM
+(see \cite{ptexjp}); characters are grouped into several classes, the
+size information of characters are specified for each class, and
 glue/kern insertions are specified for each pair of classes. Although
 the author have not tried, it may be possible to develop a program that
 `converts' a JFM to a metric for \LuaTeX-ja.  \LuaTeX-ja offers three
@@ -277,7 +282,7 @@ clash with glue/kern informations from the metric.
 
 As described in \cite{luatexref}, \LuaTeX's kerning and ligaturing
 processes are totally different from those of \TeX82.  \TeX82's process is
-done just when a (sequence of) character is appended to current
+done just when a (sequence of) character is appended to the current
 list. Thus we can interrupt this process by writing as
 |f{}irm|. However, \LuaTeX's process is \emph{node-based}, that is, the
 process will be done when a horizontal box or a paragraph is ended, so
@@ -301,7 +306,7 @@ typesetting will be divided into the following three categories:
       justifying each line.
 \end{itemize}
 In p\TeX, these three kinds of glues are treated differently. A JFM glue
-is inserted when a (sequence of) Japanese character is appended to
+is inserted when a (sequence of) Japanese character is appended to the
 current list, same as the case of alphabetic characters in \TeX82. This
 means that one can interrupt the insertion process by saying |{}|.  A
 \emph{xkanjiskip} is inserted just before `hpack' or line-breaking of a
@@ -355,10 +360,10 @@ Now we will take a look inside the insertion process itself, and describe 4~poin
 
 \begin{description}
 \item[Ignored Nodes]
-As noted in the previous subsection, the insertion process in p\TeX\ can be
-	   interrupted by saying |{}| or anything else\footnote{This is
-	   why some tricks like \texttt{ちょ\char`\{\char`\}っと} that
-	   are needed when we use \texttt{min10.tfm} work.}. This leads
+As noted in the previous subsection, the insertion process in p\TeX\ can
+	   be interrupted by saying |{}| or anything else\footnote{This
+	   is why some tricks like \texttt{ちょ\char`\{\char`\}っと} for
+	   \texttt{min10.tfm} and other `old' JFMs work.}. This leads
 	   the second row in Table~\ref{tab-jfmglue}, or
 	   Figure~\ref{fig-ptexjfm}. `The process is interrupted' means
 	   that p\TeX\ does not think the letter `】\inhibitglue' is
@@ -377,14 +382,16 @@ As noted in the previous subsection, the insertion process in p\TeX\ can be
 	   \emph{mark\_node}, \emph{whatsit\_node} and
 	   \emph{penalty\_node}---, as shown in (4).
 
-By the way, around a \emph{glyph\_node} $p$ there may be some nodes
+
+By the way, around a \emph{glyph\_node} $p$ there may be some nld odes
 	   attached to $p$. These are an accent and kerns for
-	   positioning it, and a kern from italic
+	   positioning it, and a kern from the italic
 	   correction\footnote{\TeX82 (and \LuaTeX) does not distinguish
 	   between explicit kern and a kern for italic correction. To
-	   distinguish them, \LuaTeX-ja uses an additional attribute and
+	   distinguish them, an additional subtype for kern is introduced
+	   in p\TeX. On the other hand, \LuaTeX-ja uses an additional attribute and
 	   redefines \texttt{\char`\\/}.} for $p$. It is natural that
-	   these attachments should be ignored in the process. Hence
+	   these attachments should be ignored inside the process. Hence
 	   \LuaTeX-ja takes this approach, as the latest version of
 	   p\TeX\ (p3.2). This explains (2) in the figure.
 
@@ -408,11 +415,11 @@ If the above input is processed by p\TeX, since the insertion process is
 \mc 明朝）\hbox{}\gt （ゴシック
 \end{quote}
 However this seems to be unnatural, since two Japanese fonts in the
-	   output uses the same metric, \emph{i.e.}, the same
+	   output use the same metric, i.e.,~the same
 	   typesetting rule.  Hence, we decided that Japanese fonts with
 	   the same metric are treated as one font in the insertion
 	   process of \LuaTeX-ja. Thus, the output from the above input
-	   in \LuaTeX-ja is:
+	   in \LuaTeX-ja looks like:
 \begin{quote}
 \mc 明朝）\gt （ゴシック
 \end{quote}
@@ -453,11 +460,11 @@ We thought that amounts of spaces between parentheses in above output
     \small\vrule height .5ex depth .5ex\hrulefill\ \lower.5ex\hbox{$a$}\ 
     \hrulefill\vrule height .5ex depth .5ex\cr}}}}%
 \imagfm{\jstrut ）\inhibitglue}%
-\imagfm{\jstrut\hbox to .5\zw{\hss\normalsize (1)\hss}}%
+\hbox to .5\zw{\hss\normalsize (1)\hss}%
 \imagfm{\jstrut\inhibitglue\gt （}%
 \imagfm{\jstrut\gt æ¼¢}%
 \imagfm{\jstrut\gt ）\inhibitglue}%
-\imagfm{\jstrut\hbox to .55\zw{\hss\normalsize (2)\hss}}%
+\hbox to .55\zw{\hss\normalsize (2)\hss}%
 \imagfm{\fontsize{48}{48}\selectfont\jstrut\gt\inhibitglue （}%
 \imagfm{\fontsize{48}{48}\selectfont\jstrut\smash{%
   \vtop{\lineskiplimit=\maxdimen\lineskip2pt\halign{#\cr\gt 大\cr
@@ -480,7 +487,7 @@ In p\TeX, the value of \emph{xkanjiskip} is controlled by a skip named
 
 Considering this situation of p\TeX, \LuaTeX-ja can use the value of
 	   \emph{xkanjiskip} that specified in a metric. If the value of
-	   \emph{xkanjiskip} on the user side (this is the
+	   \emph{xkanjiskip} on user side (this is the
 	   \textsf{xkanjiskip} parameter in |\ltjsetparameter|) is
 	   |\maxdimen|, then the \LuaTeX-ja use the specification from
 	   the current used metric as the actual value of
@@ -493,7 +500,7 @@ This description also applies for \emph{kanjiskip}.
 At the moment, \LuaTeX-ja can be used under plain \TeX, and under
 \LaTeXe. Generally speaking, one only has to read |luatexja.sty|, by |\input|
 command or |\usepackage| (in~\LaTeXe), if you merely want to typeset
-Japanese character.  We look more detail by parts.
+Japanese characters.  We look more detail by parts.
 
 \subsection{`Engine Extension'}
 The lowest part of \LuaTeX-ja corresponds the p\TeX\ extension as
@@ -509,7 +516,7 @@ described are the followings:
 	   assignment of |\kcatcode| can be done by a Unicode
 	   block\footnote{There are some exceptions. For example,
 	   U+FF00--FFEF (Halfwidth and Fullwidth Forms) are divided into
-	   three blocks in up\TeX.}.
+	   three blocks in recent up\TeX.}.
 
 \LuaTeX-ja uses a slightly different approach. Because there are many
 	   Unicode blocks already in Basic Multilingual Plane which are
@@ -634,9 +641,10 @@ As described in the previos subsection, \LuaTeX-ja can customize the
 range of Japanese characters.  \LuaTeX-ja predefines 8~character ranges,
 as shown in Table~\ref{tab-chrrng}.  Almost of these ranges are just the
 union of Unicode blocks, and determined from the Adobe-Japan1-6 character
-correction, and JIS~X~0208.  And, among these 8~ranges, the ranges~2, 3, 6, 7,
-and~8 are considered ranges of Japanese characters, and others are
-considered ranges of alphabetic characters.
+collection~\cite{aj16}, and JIS~X~0208.  And, among these 8~ranges, the
+	   ranges~2, 3, 6, 7, and~8 are considered ranges of Japanese
+	   characters, and others are considered ranges of alphabetic
+	   characters.
 
 This default setting is suitable for Japanese-based documents, however it
 	   causes that other packages which use Unicode fonts do not work
@@ -645,7 +653,7 @@ This default setting is suitable for Japanese-based documents, however it
 	   to the range~8, and |\textendash| provided by the |EU2|
 	   encoding used in the \emph{fontspec} package is the
 	   character U+2013, which belongs to the range~3. hence, these
-	   charatcer cannot be typeset with the default range setting.
+	   character cannot be typeset correctly with the default range setting.
 
 \begin{table}
 \caption{Predefined ranges in \LuaTeX-ja}
@@ -655,7 +663,7 @@ This default setting is suitable for Japanese-based documents, however it
 1&(Additional) Latin characters which is not belonged in the range~8.\\
 2&Greek and Cyrillic letters.\\
 3&Punctuations and miscellaneous symbols.\\
-4&Unicode blocks which does not intersect with Adobe-Japan1.\\
+4&Unicode blocks which does not intersect with Adobe-Japan1-6.\\
 5&Surrogates and supplementary private use Areas.\\
 6&Characters used in Japanese typesetting.\\
 7&Characters possibly used in CJK typesetting, but not in Japanese.\\
@@ -683,12 +691,13 @@ The control sequence |\fontfamily| in p\LaTeXe\ changes the current alphabetic
 \end{itemize}
 The same criterion is used for changing Japanese font family.
 
-To work this behavior well, a list of all encodings defined already in the
-	   document is needed. Since \LuaTeX-ja is loaded as a package,
-	   \LuaTeX-ja cannot have this list.  Hence \LuaTeX-ja adopted different
-	   approach, namely |\fontfamily{|$\langle\hbox{\it
-	   arg\/}\rangle$|}| changes the current alphabetic font family
-	   to $\langle\hbox{\it arg\/}\rangle$, if and only if:
+To work this behavior well, a list of all (alphabetic) encodings defined
+	   already in the document is needed. However, since \LuaTeX-ja
+	   is loaded as a package, \LuaTeX-ja cannot have this list.
+	   Hence \LuaTeX-ja adopted a different approach, namely
+	   |\fontfamily{|$\langle\hbox{\it arg\/}\rangle$|}| changes the
+	   current alphabetic font family to $\langle\hbox{\it
+	   arg\/}\rangle$, if and only if:
 \begin{itemize}
 \item An alphabetic font family named $\langle\hbox{\it arg\/}\rangle$ in
       the current alphabetic encoding $\langle\hbox{\it enc\/}\rangle$.
@@ -724,28 +733,30 @@ the former two packages.
 \item[The \emph{fontspec} package] The \emph{fontspec} package is built
 	   on NFSS2, hence control sequences offered by the
 	   \emph{fontspec} package, such as |\setmainfont|, are only
-	   effective for alphabetic fonts if \LuaTeX-ja is
-	   loaded. |luatexja-fontspec.sty| offers these counterparts for
-	   Japanese fonts, with additional `j' in the name of control
-	   sequences, such as |\setmainjfont|.
+	   effective for alphabetic fonts if \LuaTeX-ja is loaded. The
+	   optional package \texttt{luatexja-\penalty0fontspec.sty}
+	   offers these counterparts for Japanese fonts, with additional
+	   `j' in the name of control sequences, such as
+	   |\setmainjfont|.
 
 \item[The \emph{otf} package]
-This package is widely used for characters which is
+This package is widely used in p\TeX\ for characters which is
 not in JIS~X~0208, and for using more than one weight in \emph{mincho}
 and \emph{gothic} font families. Therefore \LuaTeX-ja supports features
-in the \emph{otf} package, by loading |luatexja-otf.sty|. Note that
-characters by |\UTF{xxxx}| and |\CID{xxxx}| are not appended to the
-current list as a \emph{glyph\_node}, so they are not affected by
-callbacks by the \emph{luaotfload} package. We have another remark; |\CID| does not work
-with TrueType fonts.
+in the \emph{otf} package, by loading \texttt{luatexja-\penalty0otf.sty}
+	   manually. Note that characters by |\UTF{xxxx}| and
+	   |\CID{xxxx}| are not appended to the current list as a
+	   \emph{glyph\_node}, so they are not affected by callbacks by
+	   the \emph{luaotfload} package. We have another remark; |\CID|
+	   does not work with TrueType fonts.
 
 \item[The \emph{listings} package]
-It is well-known that there is a patch of the \emph{listings} package for
-	   p\LaTeXe,\ called |jlisting.sty|. Generally speaking, it also
-	   can be used in \LuaTeX-ja. However, it seems to be that a
-	   Japanese character after a space does not recieve any process
-	   of the \emph{listings} package; this is inconvinient when we
-	   use the \emph{showexpl} package.
+It is well-known that there is a patch |jlisting.sty| of the
+	   \emph{listings} package for p\LaTeXe. Generally speaking, it
+	   also can be used in \LuaTeX-ja. However, it seems to be that
+	   a Japanese character after a space does not recieve any
+	   process of the \emph{listings} package; this is inconvinient
+	   when we use the \emph{showexpl} package.
 \end{description}
 
 
@@ -773,7 +784,7 @@ Subsection~\ref{ssec-pol}.
 As in Figure~\ref{fig-jfdef}, \LuaTeX-ja uses |\jfont| for defining
 Japanese font, as p\TeX.  However, since the information of the current
 Japanese font is stored into an attribute, control sequences defined by
-|\jfont| (\emph{e.g.},~|\foo| and |\bar| in Figure~\ref{fig-jfdef}) is
+|\jfont| (e.g.,~|\foo| and |\bar| in Figure~\ref{fig-jfdef}) is
 not representing a font by the means of \TeX82. In other words, each of
 these control sequences is just an assignment to an attribute, therefore
 they cannot be an argument of |\the|, |\fontname|, or |\textfont|.
@@ -781,7 +792,7 @@ they cannot be an argument of |\the|, |\fontname|, or |\textfont|.
 \subsection{Overview of the Processes}
 Now we describe an outline of the \LuaTeX-ja's process briefly.
 \begin{description}
-\item[Treatment of Linebreaks after Japanese Characters] This part is
+\item[Treatment of Line-breaks after a Japanese Character] This part is
 	   described already in Subsection~\ref{ssec-line}. Done in the
 	   |process_input_buffer| callback.
 \item[Font Replacement] In the |hyphenate| callback, \LuaTeX-ja looks
@@ -793,7 +804,7 @@ Now we describe an outline of the \LuaTeX-ja's process briefly.
 
 Furthermore the subtype of $p$ is subtracted by 1 to suppress
 	   hyphenation around it by \LuaTeX, since later processes of
-	   \LuaTeX-ja take care of all things about Japanese charaters.
+	   \LuaTeX-ja take care of all things about Japanese characters.
 \end{description}
 %
 Following processes are all executed in |pre_linebreak_filter| and
@@ -804,7 +815,7 @@ Following processes are all executed in |pre_linebreak_filter| and
 	   is the content of a horizontal box is traversed, 
 to determine what is the level of \LuaTeX-ja's internal stack at the end
 	   of the list. This is needed because of the place of
-	   |hpack_filter| callback in the source of \LuaTeX. We will discuss more
+	   the |hpack_filter| callback in the source of \LuaTeX. We will discuss more
 	   detail in Subsection~\ref{ssec-stack}.
 
 \item[Insertion of Glues/Kerns for Japanese Typesetting]
@@ -814,7 +825,7 @@ This part is already described at Subsection~\ref{ssec-jglue}.
 We will discuss the detail about this in Subsection~\ref{ssec-width}.
 \end{description}
 
-The callbacks by the \emph{luaotfload} package, e.g., replacement of
+The callbacks by the \emph{luaotfload} package, e.g.,~replacement of
 glyphs according to font features, are executed just after `Examination
 of Stack Level' above. 
 
@@ -848,7 +859,7 @@ void package(int c)
 
 Figure~\ref{fig-ltsrc} is an extract of a CWEB-source
 \texttt{tex/packaging.w} of \LuaTeX\ (SVN revision 4358). This function
-is called just when explicit |\hbox{...}| or |\vbox{...}| is ended, and
+is called just when an explicit |\hbox{...}| or |\vbox{...}| is ended, and
 the function |filtered_hpack()| is where the |hpack_filter| and then the
 actual `hpack' process are performed. Notice that the |unsave()|
 function is called before |filtered_hpack()|. This is the problem;
@@ -860,12 +871,12 @@ Lua codes in \cite{stack-mail}. Furthermore, \emph{whatsit} nodes whose
 \emph{user\_id} is 30112 (\emph{stack\_node}, for short) will be
 appended to the current horizontal list each time the current stack
 level is incremented, and their values are the values of
-|\currentgrouplevel| at that time. In the beginning of |hpack_filter|
+|\currentgrouplevel| at that time. In the beginning of the |hpack_filter|
 callback, the list in question is traversed to determine whether the
 stack level at the end of the list and that outside the box coincides.
 
 Let $x$ be the value of |\currentgrouplevel|, and $y$ be the current
-stack level, both inside the |hpack_filter| callback, i.e., outside a
+stack level, both inside the |hpack_filter| callback, i.e.,~outside a
 horizontal box. Consider a list which represents the content of the box,
 then we have:
 \begin{itemize}
@@ -914,7 +925,7 @@ same time.
 \begin{center}\unitlength=9pt\small
 \begin{picture}(15,12)(-1,-3)
 
-\color{gray10}% real glyph
+\color{grayx}% real glyph
 \put(-1,-1.5){\vrule width 6\unitlength height 7\unitlength depth 2.5\unitlength}
 
 \color{black}% real glyph :step1
@@ -923,6 +934,7 @@ same time.
 \put(5,-1.5){\line(0,1){7}\line(0,-1){2.5}}
 \put(-1,5.5){\line(1,0){6}}
 \put(-1,-4){\line(1,0){6}}
+\put(-1,0){\makebox(0,0)[r]{\strut$R$\,}}
 
 \thicklines
 \put(0,0){\vector(0,1){9}\line(0,-1){3}\vector(1,0){12}}
@@ -966,7 +978,7 @@ glyph is aligned `middle'; this setting is useful for the full-width
 middle dot `・'. We have other settings, namely, `left' and `right'.
 After that, it is shifted according to the value of |left| and |down|,
 which are specified in the metric. The final position of the real glyph
-is shown by the gray rectangle. If the amount of shifting baseline is
+is shown by the gray rectangle~$R$. If the amount of shifting the baseline is
 not zero, $M$ (and hence the real glyph) is shifted by that amount.
 
 We would like to remark briefly about the vertical position of a glyph.
@@ -985,12 +997,16 @@ that this paper and this project contribute the typesetting Japanese,
 and possibly other Asian languages, under \LuaTeX.
 
 
-
 %%% The style of the bibiliogrphy is `amsplain'.
 \providecommand{\bysame}{\leavevmode\hbox to3em{\hrulefill}\thinspace}
 \providecommand{\href}[2]{#2}
 \begin{thebibliography}{99}
 
+\bibitem{aj16}
+Adobe Systems Incorporated, \emph{Adobe-Japan1-6 Character Collection
+	for CID-Keyed Fonts}, Technical Note~\#5078, 2004.
+\url{http://partners.adobe.com/public/developer/en/font/5078.Adobe-Japan1-6.pdf}
+
 \bibitem{ptex}
 ASCII MEDIA WORKS，アスキー日本語\TeX\ (p\TeX)．\url{http://ascii.asciimw.jp/pb/ptex/}