latex3 (12mar13)

git-svn-id: svn://tug.org/texlive/trunk@29361 c570f23f-e606-0410-a88d-b1316a301751

94 files changed, 6395 insertions, 7218 deletions

diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3dt/l3dt.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3dt/l3dt.pdf
index e76c8fc915d..48bcd348b37 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3dt/l3dt.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3dt/l3dt.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3sort/l3sort.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3sort/l3sort.pdf
index 951db575eb5..58839db8756 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3sort/l3sort.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3sort/l3sort.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3flag.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3flag.pdf
index 44d306b2dc4..45893cbfaf5 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3flag.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3flag.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3regex.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3regex.pdf
index cbfc130822e..7d1eb3d244f 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3regex.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3regex.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-convert.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-convert.pdf
new file mode 100644
index 00000000000..f3963ef30bc
--- /dev/null
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-convert.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-format.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-format.pdf
index bc091420db4..3fa7baa9ca8 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-format.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str-format.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str.pdf
index 95eb5e88b2d..4d5a154cb26 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3str.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-analysis.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-analysis.pdf
index bd1b99ac1d0..6dff4edf002 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-analysis.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-analysis.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-build.pdf b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-build.pdf
index 35924b0610d..4aea8a37103 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-build.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/l3str/l3tl-build.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/xcoffins/xcoffins.pdf b/Master/texmf-dist/doc/latex/l3experimental/xcoffins/xcoffins.pdf
index 9c7873a883d..fc11336eef5 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/xcoffins/xcoffins.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/xcoffins/xcoffins.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/xgalley/l3galley.pdf b/Master/texmf-dist/doc/latex/l3experimental/xgalley/l3galley.pdf
index b6e7442ac3f..1401845d3c5 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/xgalley/l3galley.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/xgalley/l3galley.pdf
diff --git a/Master/texmf-dist/doc/latex/l3experimental/xgalley/xgalley.pdf b/Master/texmf-dist/doc/latex/l3experimental/xgalley/xgalley.pdf
index 75f98b13eac..75c826c159b 100644
--- a/Master/texmf-dist/doc/latex/l3experimental/xgalley/xgalley.pdf
+++ b/Master/texmf-dist/doc/latex/l3experimental/xgalley/xgalley.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/expl3.pdf b/Master/texmf-dist/doc/latex/l3kernel/expl3.pdf
index 820c38f6400..77eb63f6116 100644
--- a/Master/texmf-dist/doc/latex/l3kernel/expl3.pdf
+++ b/Master/texmf-dist/doc/latex/l3kernel/expl3.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/interface3.pdf b/Master/texmf-dist/doc/latex/l3kernel/interface3.pdf
index 0de151d8703..cec74ab1a1c 100644
--- a/Master/texmf-dist/doc/latex/l3kernel/interface3.pdf
+++ b/Master/texmf-dist/doc/latex/l3kernel/interface3.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/interface3.tex b/Master/texmf-dist/doc/latex/l3kernel/interface3.tex
deleted file mode 100644
index 4c0a2761e92..00000000000
--- a/Master/texmf-dist/doc/latex/l3kernel/interface3.tex
+++ /dev/null
@@ -1,89 +0,0 @@
-% \iffalse meta-comment
-%
-%% File: interfaces3.tex Copyright (C) 1990-2011 The LaTeX3 Project
-%%
-%% It may be distributed and/or modified under the conditions of the
-%% LaTeX Project Public License (LPPL), either version 1.3c of this
-%% license or (at your option) any later version.  The latest version
-%% of this license is in the file
-%%
-%%    http://www.latex-project.org/lppl.txt
-%%
-%% This file is part of the "l3kernel bundle" (The Work in LPPL)
-%% and all files in that bundle must be distributed together.
-%%
-%% The released version of this bundle is available from CTAN.
-%%
-%% -----------------------------------------------------------------------
-%%
-%% The development version of the bundle can be found at
-%%
-%%    http://www.latex-project.org/svnroot/experimental/trunk/
-%%
-%% for those people who are interested.
-%%
-%%%%%%%%%%%
-%% NOTE: %%
-%%%%%%%%%%%
-%%
-%%   Snapshots taken from the repository represent work in progress and may
-%%   not work or may contain conflicting material!  We therefore ask
-%%   people _not_ to put them into distributions, archives, etc. without
-%%   prior consultation with the LaTeX3 Project.
-%%
-%% -----------------------------------------------------------------------
-%
-% \fi
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%
-% This document will typeset the LaTeX3 interface descriptions a single
-% document. This will produce quite a large file (more than 170 pages
-% currently).
-%
-% There is also a full version of the sources (source3.tex) which additionally
-% also typesets the command implementations.
-%
-% Do not forget to generate the index (as explained on the terminal output
-% near the end of the run)!
-%
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-
-\documentclass{l3doc}
-\listfiles
-
-\begin{document}
-
-\title{The \LaTeX3 Interfaces}
-\author{%
- The \LaTeX3 Project\thanks
-   {%
-     E-mail:
-       \href{mailto:latex-team@latex-project.org}
-         {latex-team@latex-project.org}%
-   }%
-}
-
-\pagenumbering{roman}
-\maketitle
-
-%
-% First load all modules and typeset the documentation parts
-%
-
-\input{source3body}    % all the individual modules
-
-\clearpage
-
-\begingroup
-  \def\endash{--}
-  \catcode`\-\active
-  \def-{\futurelet\temp\indexdash}
-  \def\indexdash{\ifx\temp-\endash\fi}
-  \DelayPrintIndex
-\endgroup
-
-\end{document}
-
-
diff --git a/Master/texmf-dist/doc/latex/l3kernel/l3docstrip.pdf b/Master/texmf-dist/doc/latex/l3kernel/l3docstrip.pdf
index 0bd4285bf37..37e876db28b 100644
--- a/Master/texmf-dist/doc/latex/l3kernel/l3docstrip.pdf
+++ b/Master/texmf-dist/doc/latex/l3kernel/l3docstrip.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.pdf b/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.pdf
index ec18c58a785..82960bc1a10 100644
--- a/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.pdf
+++ b/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex b/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex
deleted file mode 100644
index 6a3a9d122e6..00000000000
--- a/Master/texmf-dist/doc/latex/l3kernel/l3styleguide.tex
+++ /dev/null
@@ -1,242 +0,0 @@
-\iffalse meta-comment
-
-File l3styleguide.tex Copyright (C) 2011,2012 The LaTeX3 Project
-
-It may be distributed and/or modified under the conditions of the
-LaTeX Project Public License (LPPL), either version 1.3c of this
-license or (at your option) any later version.  The latest version
-of this license is in the file
-
-   http://www.latex-project.org/lppl.txt
-
-This file is part of the "l3kernel bundle" (The Work in LPPL)
-and all files in that bundle must be distributed together.
-
-The released version of this bundle is available from CTAN.
-
-\fi
-
-\documentclass{l3doc}
-\usepackage{svn-multi}
-
-\svnid{$Id: l3styleguide.tex 2772 2011-09-07 15:07:41Z joseph $}
-\def\filedate{\svnfileyear/\svnfilemonth/\svnfileday}
-
-\title{%
-  The \LaTeX3 kernel: style guide for code authors%
-    \thanks
-      {%
-        This file describes v\svnfilerev,
-        last revised \filedate.
-      }%
-}
-\author{%
-  The \LaTeX3 Project\thanks
-    {%
-      E-mail:
-      \href{mailto:latex-team@latex-project.org}%
-        {latex-team@latex-project.org}%
-    }%
-}
-\date{Released \filedate}
-
-\begin{document}
-
-\maketitle
-
-\tableofcontents
-
-\section{Introduction}
-
-This document is intended as a style guide for authors of code and
-documentation for the \LaTeX3 kernel. It covers both aspects of coding
-style and the formatting of the sources. The aim of providing these
-guidelines is help ensure consistency of the code and sources from
-different authors. Experience suggests that in the long-term this helps
-with maintenance. There will of course be places where there are
-exceptions to these guidelines: common sense should always be
-applied!
-
-\section{Documentation style}
-
-\LaTeX3 source and documentation should be written using the document
-class \cls{l3doc} in \file{dtx} format. This class provides a number
-of logical mark up elements, which should be used where possible.
-In the main, this is standard \LaTeX{} practice, but there are a
-few points to highlight:
-\begin{itemize}
-  \item
-    Where possible, use \cs{cs} to mark up control sequences
-    rather than using a verbatim environment.
-  \item
-    Arguments which are given in braces should be marked using
-    \cs{Arg} when code-level functions are discussed, but using
-    \cs{marg} for document functions.
-  \item
-    The names \TeX{}, \LaTeX{}, \emph{etc}.\ use the normal logical mark
-    up followed by an empty group (|{}|), with the exception of |\LaTeX3|,
-    where the number should follow directly.
-  \item
-    Where in line verbatim text is used, it should be marked up
-    using the \verb=|...|= construct (\emph{i.e.}~vertical bars delimit
-    the verbatim text).
-  \item In line quotes should be marked up using the \cs{enquote}
-    function.
-  \item
-    Where numbers in the source have a mathematical meaning,
-    they should be included in math mode. Such in-line math mode
-    material should be marked up using |$...$| and  \emph{not}
-    |\(...\)|.
-\end{itemize}
-
-Line length in the source files should to be under $80$
-characters where possible, as this helps keep everything on the screen
-when editing files. In the \file{dtx} format, documentation lines start
-with a \texttt{\%}, which is usually followed by a space to leave a
-\enquote{comment margin} at the start of each line.
-
-As with code indenting (see later), nested environments and arguments
-should be indented by (at least) two spaces to make the nature of the nesting
-clear. Thus for example a typical arrangement for the \env{function}
-environment might be
-\begin{verbatim*}
-\begin{function}{\seq_gclear:N, \seq_gclear:c}
-  \begin{syntax}
-    \cs{seq_gclear:N} \meta{sequence}
-  \end{syntax}
-  Clears all entries from the \meta{sequence} globally.
-\end{function}
-\end{verbatim*}
-The \enquote{outer} \verb*|% \begin{function}| should have the customary
-space after the |%| character at the start of the line.
-
-In general, a single \env{function}  or \env{macro} environment should be
-used for a group of closely-related functions, for example argument
-specification variants. In such cases, a comma-separated list should be
-used, as shown in the preceding example.
-
-\section{Format of the code itself}
-
-The requirement for less than $80$ characters per line applies to the code
-itself as well as the surrounding documentation. A number of the general
-style principals for \LaTeX3 code apply: these are described in the following
-paragraph and an example is then given.
-
-With the exception of simple runs of parameter (|{#1}|, |#1#2|,
-\emph{etc.}), everything should divided up using spaces to make the code
-more readable. In general, these will be single spaces, but in some
-places it makes more sense to align parts of the code to emphasise
-similarity. (Tabs should not be used for introducing white space.)
-
-Each conceptually-separate step in a function should be on a separate
-line, to make the meaning clearer. Hence the \texttt{false} branch
-in the example uses two lines for the two auxiliary function uses.
-
-Within the definition, a two-space indent should be used to show each
-\enquote{level} of code. Thus in the example \cs{tl_if_empty:nTF} is
-indented by two spaces, but the two branches are indented by four
-spaces. Within the \texttt{false} branch, the need for multiple lines
-means that an additional two-space indent should be used to show that
-these lines are all part of the brace group.
-
-The result of these lay-out conventions is code which will in general
-look like the example:
-\begin{verbatim*}
-\cs_new:Npn \module_foo:nn #1#2
-  {
-    \tl_if_empty:nTF {#1}
-      { \module_foo_aux:n { X #2 } }
-      {
-        \module_foo_aux:nn {#1} {#2}
-        \module_foo_aux:n {#1#2}
-      }
-  }
-\end{verbatim*}
-
-\section{Code conventions}
-
-All code-level functions should be \enquote{long} if they accept any
-arguments, even if it seems \enquote{very unlikely} that a \cs{par} token
-will be passed. Thus \cs{cs_new_nopar:Npn} and so forth should only be used
-to create functions which accept no arguments at all.
-
-The expandability of each function should be well-defined. Functions which
-cannot be fully expanded must be \texttt{protected}. This means that expandable
-functions must themselves only contain expandable material. Functions which
-use any non-expandable material must be defined using \cs{cs_new_protected:Npn}
-or similar.
-
-When using \cs{cs_generate_variant:Nn}, group related variants together
-to make the pattern clearer. A common example is variants of a function
-which has an \texttt{N}-type first argument:
-\begin{verbatim}
-  \cs_generate_variant:Nn \foo:Nn {     NV , No }
-  \cs_generate_variant:Nn \foo:Nn { c , cV , co }
-\end{verbatim}
-
-There are cases where omitting braces from \texttt{o}-type arguments
-is desirable for performance reasons. This should only be done if the
-argument is a single token, thus for example
-\begin{verbatim}
-  \tl_set:No \l_some_tl \l_some_other_tl
-\end{verbatim}
-remains clear and can be used where appropriate.
-
-\section{Private and internal functions}
-
-Private functions (those starting \cs{__}) should not be used between modules.
-The only exception is where a \enquote{family} of modules share some
-\enquote{internal} methods: this happens most obviously in the kernel itself.
-Any internal functions or variables \emph{must} be documented in the same way
-as public ones.
-
-The \pkg{l3docstrip} method should be used for internal functions in a module.
-This requires a line
-\begin{quote}
-  \ttfamily
-  \%<@@=\meta{module}>
-\end{quote}
-at the start of the source (\texttt{.dtx}) file, with internal functions
-then written in the form
-\begin{verbatim}
-  \cs_new_protected:Npn \@@_function:nn #1#2
-    ...
-\end{verbatim}
-
-\section{Auxiliary functions}
-
-In general, the team encourage the use of descriptive names in \LaTeX3 code.
-Thus many helper functions will have names which describe briefly what they do,
-rather than simply indicating that they are auxiliary to some higher-level
-function. However, there are places where one or more \texttt{aux} functions
-are required. Where possible, these should be differentiated by signature
-\begin{verbatim}
-  \cs_new_protected:Npn \@@_function:nn #1#2
-    {
-      ...
-    }
-  \cs_new_protected:Npn \@@_function_aux:nn #1#2
-    {
-      ...
-    }
-  \cs_new_protected:Npn \@@_function_aux:w #1#2 \q_stop
-    {
-      ...
-    }
-\end{verbatim}
-Where more than one auxiliary shares the same signature, the recommended naming
-scheme is \texttt{auxi}, \texttt{auxii} and so on.
-\begin{verbatim}
-  \cs_new_protected:Npn \@@_function_auxi:nn #1#2
-    {
-      ...
-    }
-  \cs_new_protected:Npn \@@_function_auxii:nn #1#2
-    {
-      ...
-    }
-\end{verbatim}
-The use of \texttt{aux_i}, \texttt{aux_ii}, \emph{etc.}\ is discouraged as this
-conflicts with the convention used by \cs{use_i:nn} and related functions.
-
-\end{document}
diff --git a/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.pdf b/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.pdf
index 8e6903f95a5..2b7d6cc8b35 100644
--- a/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.pdf
+++ b/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.tex b/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.tex
deleted file mode 100644
index 4dfc70e0e97..00000000000
--- a/Master/texmf-dist/doc/latex/l3kernel/l3syntax-changes.tex
+++ /dev/null
@@ -1,110 +0,0 @@
-\iffalse meta-comment
-
-File l3syntax-changes.tex Copyright (C) 2011-2012 The LaTeX3 Project
-
-It may be distributed and/or modified under the conditions of the
-LaTeX Project Public License (LPPL), either version 1.3c of this
-license or (at your option) any later version.  The latest version
-of this license is in the file
-
-   http://www.latex-project.org/lppl.txt
-
-This file is part of the "l3kernel bundle" (The Work in LPPL)
-and all files in that bundle must be distributed together.
-
-The released version of this bundle is available from CTAN.
-
-\fi
-
-\documentclass{l3doc}
-
-\usepackage{svn-multi}
-
-\svnid{$Id: l3syntax-changes.tex 4048 2012-08-02 09:49:10Z joseph $}
-\def\filedate{\svnfileyear/\svnfilemonth/\svnfileday}
-
-\title{%
-  Syntax changes in \LaTeX3 functions
-    \thanks
-      {%
-        This file describes v\svnfilerev,
-        last revised \filedate.
-      }%
-}
-\author{%
-  The \LaTeX3 Project\thanks
-    {%
-      E-mail:
-      \href{mailto:latex-team@latex-project.org}%
-        {latex-team@latex-project.org}%
-    }%
-}
-\date{Released \filedate}
-
-\newcommand{\TF}{\textit{(TF)}}
-
-\begin{document}
-
-\maketitle
-
-This file lists functions whose syntax has changed after August 2011,
-with an approximate date.
-
-\section{August 2011}
-
-\begin{itemize}
-  \item \cs{tl_if_single:n\TF} recognized any non-zero number of
-    explicit spaces as \meta{true}, and did not ignore trailing spaces.
-    Now it is \meta{true} for
-    \[
-      \meta{optional spaces}
-      \meta{normal token or brace group}
-      \meta{optional spaces}.
-    \]
-  \item \cs{tl_reverse:n} stripped outer braces and lost unprotected spaces.
-    Now it keeps spaces, leaves unbraced single tokens unbraced, and
-    braced groups braced.
-  \item \cs{tl_trim_spaces:n} only removed one leading and trailing space.
-    Now removes recursively. Also, on the left it used to strip implicit
-    and explicit spaces with any character code. Now it strips only explicit
-    space characters $(32,10)$.
-\end{itemize}
-
-\section{September 2011}
-
-\begin{itemize}
-\item clist functions which receive an \texttt{n}-type comma list argument
-  now trim spaces from each item in the argument.
-\end{itemize}
-
-\section{June 2012}
-
-\begin{itemize}
-  \item Access to list functions now indexes from~$1$, not from~$0$.
-  This applies to multiple choices in the \pkg{l3keys} module and
-  the \cs{clist_item:Nn}, \cs{seq_item:Nn} and \cs{tl_item:Nn}
-  functions.
-  \item \cs{tl_trim_spaces:n} now requires a variable number of
-  expansions to fully expand, rather than exactly two.  Of course,
-  \texttt{x}-type expansion still correctly evaluates this function.
-\end{itemize}
-
-\section{July 2012}
-
-\begin{itemize}
-  \item The \cs{tl_if_head_eq_meaning:nN}, \cs{tl_if_head_eq_catcode:nN}
-    and \cs{tl_if_head_eq_charcode:nN} conditionals now never match when
-    their first argument is empty.
-\end{itemize}
-
-\section{August 2012}
-
-\begin{itemize}
-  \item \cs{lua_now:x} is now a standard \texttt{x}-type expansion of
-    \cs{lua_now:n}, which does no expansion. Engine-level expansion is moved
-    to \cs{lua_now_x:n}, reflecting the fact that this is non-standard in the
-    same way as for example \cs{str_if_eq_x:nn(TF)}.
-\end{itemize}
-
-
-\end{document}
diff --git a/Master/texmf-dist/doc/latex/l3kernel/source3.pdf b/Master/texmf-dist/doc/latex/l3kernel/source3.pdf
index 3821467a59e..b46ea2254f9 100644
--- a/Master/texmf-dist/doc/latex/l3kernel/source3.pdf
+++ b/Master/texmf-dist/doc/latex/l3kernel/source3.pdf
diff --git a/Master/texmf-dist/doc/latex/l3kernel/source3.tex b/Master/texmf-dist/doc/latex/l3kernel/source3.tex
deleted file mode 100644
index 22c3c44048d..00000000000
--- a/Master/texmf-dist/doc/latex/l3kernel/source3.tex
+++ /dev/null
@@ -1,106 +0,0 @@
-% \iffalse meta-comment
-%
-%% File: source3.tex Copyright (C) 1990-2011 The LaTeX3 Project
-%%
-%% It may be distributed and/or modified under the conditions of the
-%% LaTeX Project Public License (LPPL), either version 1.3c of this
-%% license or (at your option) any later version.  The latest version
-%% of this license is in the file
-%%
-%%    http://www.latex-project.org/lppl.txt
-%%
-%% This file is part of the "l3kernel bundle" (The Work in LPPL)
-%% and all files in that bundle must be distributed together.
-%%
-%% The released version of this bundle is available from CTAN.
-%%
-%% -----------------------------------------------------------------------
-%%
-%% The development version of the bundle can be found at
-%%
-%%    http://www.latex-project.org/svnroot/experimental/trunk/
-%%
-%% for those people who are interested.
-%%
-%%%%%%%%%%%
-%% NOTE: %%
-%%%%%%%%%%%
-%%
-%%   Snapshots taken from the repository represent work in progress and may
-%%   not work or may contain conflicting material!  We therefore ask
-%%   people _not_ to put them into distributions, archives, etc. without
-%%   prior consultation with the LaTeX3 Project.
-%%
-%% -----------------------------------------------------------------------
-%
-% \fi
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%
-% This document will typeset the LaTeX3 sources as a single document.
-% This will produce quite a large file (more than 780 pages).
-%
-% There is also a shorter version (interface3.tex) that only typesets the
-% command % interface descriptions.
-%
-% Do not forget to generate the index (as explained on the terminal output
-% near the end of the run)!
-%
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-\documentclass{l3doc}
-\listfiles
-
-\begin{document}
-
-\title{The \LaTeX3 Sources}
-\author{%
- The \LaTeX3 Project\thanks
-   {%
-     E-mail:
-       \href{mailto:latex-team@latex-project.org}
-         {latex-team@latex-project.org}%
-   }%
-}
-
-\pagenumbering{roman}
-\maketitle
-
-%
-% First load all modules and typeset the documentation parts
-%
-
-\input{source3body}    % all the individual modules
-
-%
-% Now reload all modules and typeset the implementation parts
-%
-
-\part{Implementation}
-
-\def\maketitle{}
-\EnableImplementation
-\DisableDocumentation
-\DocInputAgain
-
-\clearpage
-\pagestyle{headings}
-
-% Make TeX shut up.
-\hbadness=10000
-\newcount\hbadness
-\hfuzz=\maxdimen
-
-\PrintChanges
-\clearpage
-
-\begingroup
-  \def\endash{--}
-  \catcode`\-\active
-  \def-{\futurelet\temp\indexdash}
-  \def\indexdash{\ifx\temp-\endash\fi}
-
-  \DelayPrintIndex
-\endgroup
-
-\end{document}
diff --git a/Master/texmf-dist/doc/latex/l3kernel/source3body.tex b/Master/texmf-dist/doc/latex/l3kernel/source3body.tex
deleted file mode 100644
index c5dbc33a7b3..00000000000
--- a/Master/texmf-dist/doc/latex/l3kernel/source3body.tex
+++ /dev/null
@@ -1,448 +0,0 @@
-% \iffalse meta-comment
-%
-%% File: source3body.tex Copyright (C) 1990-2012 The LaTeX3 Project
-%%
-%% It may be distributed and/or modified under the conditions of the
-%% LaTeX Project Public License (LPPL), either version 1.3c of this
-%% license or (at your option) any later version.  The latest version
-%% of this license is in the file
-%%
-%%    http://www.latex-project.org/lppl.txt
-%%
-%% This file is part of the "l3kernel bundle" (The Work in LPPL)
-%% and all files in that bundle must be distributed together.
-%%
-%% The released version of this bundle is available from CTAN.
-%%
-%% -----------------------------------------------------------------------
-%%
-%% The development version of the bundle can be found at
-%%
-%%    http://www.latex-project.org/svnroot/experimental/trunk/
-%%
-%% for those people who are interested.
-%%
-%%%%%%%%%%%
-%% NOTE: %%
-%%%%%%%%%%%
-%%
-%%   Snapshots taken from the repository represent work in progress and may
-%%   not work or may contain conflicting material!  We therefore ask
-%%   people _not_ to put them into distributions, archives, etc. without
-%%   prior consultation with the LaTeX3 Project.
-%%
-%% -----------------------------------------------------------------------
-%
-% \fi
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%
-% This file is used by
-%
-%  source3.tex            % documentation including implementation
-%
-%  interface3.tex         % only interface documentation
-%
-%
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-
-\begin{abstract}
-
-\setlength\parindent{0pt}
-\setlength\parskip{\baselineskip}
-
-\noindent
-This is the reference documentation for the \pkg{expl3}
-programming environment. The \pkg{expl3} modules set up an experimental
-naming scheme for \LaTeX{} commands, which allow the \LaTeX{} programmer
-to systematically name functions and variables, and specify the argument
-types of functions.
-
-The \TeX{} and \eTeX{} primitives are all given a new name according to
-these conventions. However, in the main direct use of the primitives is
-not required or encouraged: the \pkg{expl3} modules define an
-independent low-level \LaTeX3 programming language.
-
-At present, the \pkg{expl3} modules are designed to be loaded on top of
-\LaTeXe{}. In time, a \LaTeX3 format will be produced based on this code.
-This allows the code to be used in \LaTeXe{} packages \emph{now} while a
-stand-alone \LaTeX3 is developed.
-
-\begin{bfseries}
-  While \pkg{expl3} is still experimental, the bundle is now regarded as
-  broadly stable. The syntax conventions and functions provided are now
-  ready for wider use. There may still be changes to some functions, but
-  these will be minor when compared to the scope of \pkg{expl3}.
-
-  New modules will be added to the distributed version of \pkg{expl3} as
-  they reach maturity.
-\end{bfseries}
-
-\end{abstract}
-
-\clearpage
-
-{%
-  \def\\{:}% fix "newlines" in the ToC
-  \tableofcontents
-}
-
-\clearpage
-\pagenumbering{arabic}
-
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%
-% Each of the following \DocInput lines includes a file with extension
-% .dtx. Each of these files may be typeset separately. For instance
-%   pdflatex l3box.dtx
-% will typeset the source of the LaTeX3 box commands. If you use the
-% Makefile, the index will be generated automatically; e.g.,
-%   make doc F=l3box
-%
-% If this file is processed, each of these separate dtx files will be
-% contained as a part of a single document.
-%
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
-\makeatletter
-\def\partname{Part}
-\def\maketitle{\clearpage\part{\@title}}
-\let\thanks\@gobble
-\let\DelayPrintIndex\PrintIndex
-\let\PrintIndex\@empty
-\makeatother
-
-\part{Introduction to \pkg{expl3} and this document}
-
-This document is intended to act as a comprehensive reference manual
-for the \pkg{expl3} language. A general guide to the \LaTeX3
-programming language is found in \href{expl3.pdf}{expl3.pdf}.
-
-\section{Naming functions and variables}
-
-\LaTeX3 does not use \texttt{@} as a \enquote{letter} for defining
-internal macros.  Instead, the symbols |_| and \texttt{:}
-are used in internal macro names to provide structure. The name of
-each \emph{function} is divided into logical units using \texttt{_},
-while \texttt{:} separates the \emph{name} of the function from the
-\emph{argument specifier} (\enquote{arg-spec}). This describes the arguments
-expected by the function. In most cases, each argument is represented
-by a single letter. The complete list of arg-spec letters for a function
-is referred to as the \emph{signature} of the function.
-
-Each function name starts with the \emph{module} to which it belongs.
-Thus apart from a small number of very basic functions, all \pkg{expl3}
-function names contain at least one underscore to divide the module
-name from the descriptive name of the function. For example, all
-functions concerned with comma lists are in module \texttt{clist} and
-begin \cs{clist_}.
-
-Every function must include an argument specifier. For functions which
-take no arguments, this will be blank and the function name will end
-\texttt{:}. Most functions take one or more arguments, and use the
-following argument specifiers:
-\begin{description}
-  \item[\texttt{D}] The \texttt{D} specifier means \emph{do not use}.
-    All of the \TeX{} primitives are initially \cs{let} to a \texttt{D}
-    name, and some are then given a second name.  Only the kernel
-    team should use anything with a \texttt{D} specifier!
-  \item[\texttt{N} and \texttt{n}] These mean \emph{no manipulation},
-    of a single token for \texttt{N} and of a set of tokens given in
-    braces for \texttt{n}. Both pass the argument through exactly as
-    given. Usually, if you use a single token for an \texttt{n} argument,
-    all will be well.
-  \item[\texttt{c}] This means \emph{csname}, and indicates that the
-    argument will be turned into a csname before being used. So
-    So \cs{foo:c} |{ArgumentOne}| will act in the same way as \cs{foo:N}
-    \cs{ArgumentOne}.
-  \item[\texttt{V} and \texttt{v}] These mean \emph{value
-    of variable}. The \texttt{V} and \texttt{v} specifiers are used to
-    get the content of a variable without needing to worry about the
-    underlying \TeX{} structure containing the data. A \texttt{V}
-    argument will be a single token (similar to \texttt{N}), for example
-    \cs{foo:V} \cs{MyVariable}; on the other hand, using \texttt{v} a
-    csname is constructed first, and then the value is recovered, for
-    example \cs{foo:v} |{MyVariable}|.
-  \item[\texttt{o}] This means \emph{expansion once}. In general, the
-    \texttt{V} and \texttt{v} specifiers are favoured over \texttt{o}
-    for recovering stored information. However, \texttt{o} is useful
-    for correctly processing information with delimited arguments.
-  \item[\texttt{x}] The \texttt{x} specifier stands for \emph{exhaustive
-    expansion}: every token in the argument is fully expanded until only
-    unexpandable ones remain. The \TeX{} \tn{edef} primitive carries out
-    this type of expansion. Functions which feature an \texttt{x}-type
-    argument are in general \emph{not} expandable, unless specifically
-    noted.
-  \item[\texttt{f}] The \texttt{f} specifier stands for \emph{full
-    expansion}, and in contrast to \texttt{x} stops at the first
-    non-expandable item (reading the argument from left to right) without
-    trying to expand it. For example, when setting a token list
-    variable (a macro used for storage), the sequence
-    \begin{verbatim}
-      \tl_set:Nn \l_mya_tl { A }
-      \tl_set:Nn \l_myb_tl { B }
-      \tl_set:Nf \l_mya_tl { \l_mya_tl \l_myb_tl }
-    \end{verbatim}
-    will leave |\l_mya_tl| with the content |A\l_myb_tl|, as |A| cannot
-    be expanded and so terminates expansion before |\l_myb_tl| is considered.
-  \item[\texttt{T} and \texttt{F}] For logic tests, there are the branch
-    specifiers \texttt{T} (\emph{true}) and \texttt{F} (\emph{false}).
-    Both specifiers treat the input in the same way as \texttt{n} (no
-    change), but make the logic much easier to see.
-  \item[\texttt{p}] The letter \texttt{p} indicates \TeX{}
-    \emph{parameters}. Normally this will be used for delimited
-    functions as \pkg{expl3} provides better methods for creating simple
-    sequential arguments.
-  \item[\texttt{w}] Finally, there is the \texttt{w} specifier for
-    \emph{weird} arguments. This covers everything else, but mainly
-    applies to delimited values (where the argument must be terminated
-    by some arbitrary string).
-\end{description}
-Notice that the argument specifier describes how the argument is
-processed prior to being passed to the underlying function. For example,
-\cs{foo:c} will take its argument, convert it to a control sequence and
-pass it to \cs{foo:N}.
-
-Variables are named in a similar manner to functions, but begin with
-a single letter to define the type of variable:
-\begin{description}
-  \item[\texttt{c}] Constant: global parameters whose value should not
-    be changed.
-  \item[\texttt{g}] Parameters whose value should only be set globally.
-  \item[\texttt{l}] Parameters whose value should only be set locally.
-\end{description}
-Each variable name is then build up in a similar way to that of a
-function, typically starting with the module\footnote{The module names are
-  not used in case of generic scratch registers defined in the data
-  type modules, e.g., the
-  \texttt{int} module contains some scratch variables called \cs{l_tmpa_int},
-  \cs{l_tmpb_int}, and so on. In such a case adding the module name up front
-  to denote the module
-  and in the back to indicate the type, as in
-  \cs{l_int_tmpa_int} would be very unreadable.}  name
-and then a descriptive part.
-Variables end with a short identifier to show the variable type:
-\begin{description}
-  \item[\texttt{bool}] Either true or false.
-  \item[\texttt{box}] Box register.
-  \item[\texttt{clist}] Comma separated list.
-  \item[\texttt{coffin}] a \enquote{box with handles} --- a higher-level data
-     type for carrying out |box| alignment operations.
-  \item[\texttt{dim}] \enquote{Rigid} lengths.
-  \item[\texttt{fp}] floating-point values;
-  \item[\texttt{int}] Integer-valued count register.
-  \item[\texttt{prop}] Property list.
-  \item[\texttt{seq}] \enquote{Sequence}: a data-type used to implement lists
-    (with access at both ends) and stacks.
-  \item[\texttt{skip}] \enquote{Rubber} lengths.
-  \item[\texttt{stream}] An input or output stream (for reading from or
-    writing to, respectively).
-  \item[\texttt{tl}] Token list variables: placeholder for a token list.
-\end{description}
-
-\subsection{Terminological inexactitude}
-
-A word of warning. In this document, and others referring to the \pkg{expl3}
-programming modules, we often refer to \enquote{variables} and
-\enquote{functions} as if they
-were actual constructs from a real programming language.  In truth, \TeX{}
-is a macro processor, and functions are simply macros that may or may not take
-arguments and expand to their replacement text.  Many of the common variables
-are \emph{also} macros, and if placed into the input stream will simply expand
-to their definition as well~--- a \enquote{function} with no arguments and a
-\enquote{token list variable} are in truth one and the same.  On the other
-hand, some \enquote{variables} are actually registers that must be
-initialised and their values set and retrieved with specific functions.
-
-The conventions of the \pkg{expl3} code are designed to clearly separate the
-ideas of \enquote{macros that contain data} and
-\enquote{macros that contain code}, and a
-consistent wrapper is applied to all forms of \enquote{data} whether they be
-macros or
-actually registers.  This means that sometimes we will use phrases like
-\enquote{the function returns a value}, when actually we just mean
-\enquote{the macro expands to something}. Similarly, the term
-\enquote{execute} might be used in place of \enquote{expand}
-or it might refer to the more specific case of
-\enquote{processing in \TeX's stomach}
-(if you are familiar with the \TeX{}book parlance).
-
-If in doubt, please ask; chances are we've been hasty in writing certain
-definitions and need to be told to tighten up our terminology.
-
-\section{Documentation conventions}
-
-This document is typeset with the experimental \pkg{l3doc} class;
-several conventions are used to help describe the features of the code.
-A number of conventions are used here to make the documentation clearer.
-
-Each group of related functions is given in a box. For a function with
-a \enquote{user} name, this might read:
-\begin{function}{\ExplSyntaxOn, \ExplSyntaxOff}
-  \begin{syntax}
-    \cs{ExplSyntaxOn} \dots{} \cs{ExplSyntaxOff}
-  \end{syntax}
-  The textual description of how the function works would appear here. The
-  syntax of the function is shown in mono-spaced text to the right of
-  the box. In this example, the function takes no arguments and so the
-  name of the function is simply reprinted.
-\end{function}
-
-For programming functions, which use \texttt{_} and \texttt{:} in their name
-there are a few additional conventions: If two related functions are given
-with identical names but different argument specifiers, these are termed
-\emph{variants} of each other, and the latter functions are printed in grey to
-show this more clearly. They will carry out the same function but will take
-different types of argument:
-\begin{function}{\seq_new:N, \seq_new:c}
-  \begin{syntax}
-    \cs{seq_new:N} \meta{sequence}
-  \end{syntax}
-  When a number of variants are described, the arguments are usually
-  illustrated only for the base function. Here, \meta{sequence} indicates
-  that \cs{seq_new:N} expects the name of a sequence. From the argument
-  specifier, \cs{seq_new:c} also expects a sequence name, but as a
-  name rather than as a control sequence. Each argument given in the
-  illustration should be described in the following text.
-\end{function}
-
-\paragraph{Fully expandable functions}
-\hypertarget{expstar}{Some functions are fully expandable},
-which allows it to be used within
-an \texttt{x}-type argument (in plain \TeX{} terms, inside an \cs{edef}),
-as well as within an \texttt{f}-type argument.
-These fully expandable functions are indicated in the documentation by
-a star:
-\begin{function}[EXP]{\cs_to_str:N}
-  \begin{syntax}
-    \cs{cs_to_str:N} \meta{cs}
-  \end{syntax}
-  As with other functions, some text should follow which explains how
-  the function works. Usually, only the star will indicate that the
-  function is expandable. In this case, the function expects a \meta{cs},
-  shorthand for a \meta{control sequence}.
-\end{function}
-
-\paragraph{Restricted expandable functions}
-\hypertarget{rexpstar}{A few functions are fully expandable} but cannot be fully expanded within
-an \texttt{f}-type argument. In this case a hollow star is used to indicate
-this:
-\begin{function}[rEXP]{\seq_map_function:NN}
-  \begin{syntax}
-    \cs{seq_map_function:NN} \meta{seq} \meta{function}
-  \end{syntax}
-\end{function}
-
-\paragraph{Conditional functions}
-\hypertarget{explTF}{Conditional (\texttt{if}) functions}
-are normally defined in three variants, with
-\texttt{T}, \texttt{F} and \texttt{TF} argument specifiers. This allows
-them to be used for different \enquote{true}/\enquote{false} branches,
-depending on
-which outcome the conditional is being used to test. To indicate this
-without repetition, this information is given in a shortened form:
-\begin{function}[EXP,TF]{\xetex_if_engine:}
-  \begin{syntax}
-    \cs{xetex_if_engine:TF} \Arg{true code} \Arg{false code}
-  \end{syntax}
-  The underlining and italic of \texttt{TF} indicates that
-  \cs{xetex_if_engine:T}, \cs{xetex_if_engine:F} and
-  \cs{xetex_if_engine:TF} are all available. Usually, the illustration
-  will use the \texttt{TF} variant, and so both \meta{true code}
-  and \meta{false code} will be shown. The two variant forms \texttt{T} and
-  \texttt{F} take only \meta{true code} and \meta{false code}, respectively.
-  Here, the star also shows that this function is expandable.
-  With some minor exceptions, \emph{all} conditional functions in the
-  \pkg{expl3} modules should be defined in this way.
-\end{function}
-
-Variables, constants and so on are described in a similar manner:
-\begin{variable}{\l_tmpa_tl}
-  A short piece of text will describe the variable: there is no
-  syntax illustration in this case.
-\end{variable}
-
-In some cases, the function is similar to one in \LaTeXe{} or plain \TeX{}.
-In these cases, the text will include an extra \enquote{\textbf{\TeX{}hackers
-note}} section:
-\begin{function}[EXP]{\token_to_str:N}
-  \begin{syntax}
-    \cs{token_to_str:N} \meta{token}
-  \end{syntax}
-  The normal description text.
-  \begin{texnote}
-    Detail for the experienced \TeX{} or \LaTeXe\ programmer. In this
-    case, it would point out that this function is the \TeX{} primitive
-    \cs{string}.
-  \end{texnote}
-\end{function}
-
-\section{Formal language conventions which apply generally}
-
-As this is a formal reference guide for \LaTeX3 programming, the descriptions
-of functions are intended to be reasonably \enquote{complete}. However, there
-is also a need to avoid repetition. Formal ideas which apply to general
-classes of function are therefore summarised here.
-
-For tests which have a \texttt{TF} argument specification, the test if
-evaluated to give a logically \texttt{TRUE} or \texttt{FALSE} result.
-Depending on this result, either the \meta{true code} or the \meta{false code}
-will be left in the input stream. In the case where the test is expandable,
-and a predicate (|_p|) variant is available, the logical value determined by
-the test is left in the input stream: this will typically be part of a larger
-logical construct.
-
-\section{\TeX{} concepts not supported by \LaTeX3{}}
-
-The \TeX{} concept of an \enquote{\cs{outer}} macro is \emph{not supported}
-at all by \LaTeX3{}. As such, the functions provided here may break when
-used on top of \LaTeXe{} if \cs{outer} tokens are used in the arguments.
-
-\DisableImplementation
-
-\DocInput{l3bootstrap.dtx}
-\DocInput{l3names.dtx}
-\DocInput{l3basics.dtx}
-\DocInput{l3expan.dtx}
-\DocInput{l3prg.dtx}
-\DocInput{l3quark.dtx}
-\DocInput{l3token.dtx}
-\DocInput{l3int.dtx}
-\DocInput{l3skip.dtx}
-\DocInput{l3tl.dtx}
-\DocInput{l3seq.dtx}
-\DocInput{l3clist.dtx}
-\DocInput{l3prop.dtx}
-\DocInput{l3box.dtx}
-\DocInput{l3coffins.dtx}
-\DocInput{l3color.dtx}
-\DocInput{l3msg.dtx}
-\DocInput{l3keys.dtx}
-\DocInput{l3file.dtx}
-\DocInput{l3fp.dtx}
-% To get the various submodules of l3fp to appear in the implementation
-% part only, they have to be added to the documentation list after typesetting
-% the 'user' part just for the main module.
-\ExplSyntaxOn
-\clist_gput_right:Nn \g_docinput_clist
-  {
-    l3fp-aux.dtx ,
-    l3fp-traps.dtx ,
-    l3fp-round.dtx ,
-    l3fp-parse.dtx ,
-    l3fp-logic.dtx ,
-    l3fp-basics.dtx ,
-    l3fp-extended.dtx ,
-    l3fp-expo.dtx ,
-    l3fp-trig.dtx ,
-    l3fp-convert.dtx ,
-    l3fp-assign.dtx ,
-    l3fp-old.dtx ,
-  }
-\ExplSyntaxOff
-\DocInput{l3luatex.dtx}
-
-\DocInput{l3candidates.dtx}
-
-\endinput
diff --git a/Master/texmf-dist/doc/latex/l3packages/l3keys2e/l3keys2e.pdf b/Master/texmf-dist/doc/latex/l3packages/l3keys2e/l3keys2e.pdf
index 68329876230..8874180a75c 100644
--- a/Master/texmf-dist/doc/latex/l3packages/l3keys2e/l3keys2e.pdf
+++ b/Master/texmf-dist/doc/latex/l3packages/l3keys2e/l3keys2e.pdf
diff --git a/Master/texmf-dist/doc/latex/l3packages/xfrac/xfrac.pdf b/Master/texmf-dist/doc/latex/l3packages/xfrac/xfrac.pdf
index e29e940df36..af8bac1e2ac 100644
--- a/Master/texmf-dist/doc/latex/l3packages/xfrac/xfrac.pdf
+++ b/Master/texmf-dist/doc/latex/l3packages/xfrac/xfrac.pdf
diff --git a/Master/texmf-dist/doc/latex/l3packages/xparse/xparse.pdf b/Master/texmf-dist/doc/latex/l3packages/xparse/xparse.pdf
index edb43daa4a5..9763d473dec 100644
--- a/Master/texmf-dist/doc/latex/l3packages/xparse/xparse.pdf
+++ b/Master/texmf-dist/doc/latex/l3packages/xparse/xparse.pdf
diff --git a/Master/texmf-dist/doc/latex/l3packages/xtemplate/xtemplate.pdf b/Master/texmf-dist/doc/latex/l3packages/xtemplate/xtemplate.pdf
index f72208d5866..fa4a5766134 100644
--- a/Master/texmf-dist/doc/latex/l3packages/xtemplate/xtemplate.pdf
+++ b/Master/texmf-dist/doc/latex/l3packages/xtemplate/xtemplate.pdf
diff --git a/Master/texmf-dist/makeindex/l3kernel/l3doc.ist b/Master/texmf-dist/makeindex/l3kernel/l3doc.ist
deleted file mode 100644
index 781c87e50f2..00000000000
--- a/Master/texmf-dist/makeindex/l3kernel/l3doc.ist
+++ /dev/null
@@ -1,72 +0,0 @@
-%%
-%% This is file `l3doc.ist',
-%% generated with the docstrip utility.
-%%
-%% The original source files were:
-%%
-%% l3doc.dtx  (with options: `docist')
-%% 
-%% 
-%% EXPERIMENTAL CODE
-%% 
-%% Do not distribute this file without also distributing the
-%% source files specified above.
-%% 
-%% Do not distribute a modified version of this file.
-%% 
-%% 
-%% File: l3doc.dtx Copyright (C) 1990-2012 The LaTeX3 project
-%%
-%% It may be distributed and/or modified under the conditions of the
-%% LaTeX Project Public License (LPPL), either version 1.3c of this
-%% license or (at your option) any later version.  The latest version
-%% of this license is in the file
-%%
-%%    http://www.latex-project.org/lppl.txt
-%%
-%% This file is part of the "l3kernel bundle" (The Work in LPPL)
-%% and all files in that bundle must be distributed together.
-%%
-%% The released version of this bundle is available from CTAN.
-%%
-%% -----------------------------------------------------------------------
-%%
-%% The development version of the bundle can be found at
-%%
-%%    http://www.latex-project.org/svnroot/experimental/trunk/
-%%
-%% for those people who are interested.
-%%
-%%%%%%%%%%%
-%% NOTE: %%
-%%%%%%%%%%%
-%%
-%%   Snapshots taken from the repository represent work in progress and may
-%%   not work or may contain conflicting material!  We therefore ask
-%%   people _not_ to put them into distributions, archives, etc. without
-%%   prior consultation with the LaTeX3 Project.
-%%
-%% -----------------------------------------------------------------------
-actual '='
-quote '!'
-level '#'
-preamble
-"\n \\begin{theindex} \n \\makeatletter\\scan@allowedfalse\n"
-postamble
-"\n\n \\end{theindex}\n"
-item_x1   "\\efill \n \\subitem "
-item_x2   "\\efill \n \\subsubitem "
-delim_0   "\\pfill "
-delim_1   "\\pfill "
-delim_2   "\\pfill "
-lethead_prefix   "{\\bfseries\\hfil "
-lethead_suffix   "\\hfil}\\nopagebreak\n"
-lethead_flag       1
-heading_prefix   "{\\bfseries\\hfil "
-heading_suffix   "\\hfil}\\nopagebreak\n"
-headings_flag       1
-
-page_precedence "rnaA"
-%% 
-%%
-%% End of file `l3doc.ist'.
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3dt/l3dt.dtx b/Master/texmf-dist/source/latex/l3experimental/l3dt/l3dt.dtx
index 984739d1efd..63a3218f06a 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3dt/l3dt.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3dt/l3dt.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File l3dt.dtx Copyright (C) 2011,2012 The LaTeX3 Project
+%% File l3dt.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -36,7 +36,7 @@
 %
 %<*driver|package>
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3dt.dtx 4190 2012-09-03 00:23:31Z bruno $
+\GetIdInfo$Id: l3dt.dtx 4420 2013-01-08 20:00:04Z joseph $
   {L3 Experimental data tables}
 %</driver|package>
 %<*driver>
@@ -1195,7 +1195,7 @@
   }
 %    \end{macrocode}
 %   The second iteration is along the row. This is basically the same as
-%   \cs{prop_if_in:NnTF} with the \cs{q_@@} in place of \cs{q_prop}.
+%   \cs{prop_if_in:NnTF} with the \cs{q_@@} in place of \cs{q__prop}.
 %    \begin{macrocode}
 \cs_new:Npn \@@_if_in_row:nn #1#2
   {
@@ -1204,7 +1204,7 @@
   }
 \cs_new:Npn \@@_if_in_row:nwn #1 \q_@@ #2 \q_@@ #3
   {
-    \str_if_eq:xxTF {#1} {#2}
+    \str_if_eq_x:nnTF {#1} {#2}
       { \@@_if_in_row:N }
       { \@@_if_in_row:nwn {#1} }
   }
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3flag.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3flag.dtx
index d3b17183671..64d23d43896 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3flag.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3flag.dtx
@@ -210,7 +210,7 @@
     \else:
       \exp_after:wN \use_none_delimit_by_q_stop:w
     \fi:
-    \cs_set_eq:cN { @@_#2_#1: } \c_undefined:D
+    \cs_set_eq:cN { @@_#2_#1: } \tex_undefined:D
     \exp_after:wN \@@_clear:ww
     \int_use:N \__int_eval:w \c_one + #1 ;
     #2 \q_stop
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3regex.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3regex.dtx
index 3d25a841a80..7260ca7667f 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3regex.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3regex.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3regex.dtx Copyright (C) 2011-2012 The LaTeX3 Project
+%% File: l3regex.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3regex.dtx 4341 2012-11-27 08:39:42Z bruno $
+\GetIdInfo$Id: l3regex.dtx 4455 2013-01-22 20:38:19Z bruno $
   {L3 Experimental regular expressions}
 %</driver|package>
 %<*driver>
@@ -320,7 +320,11 @@
 % still be escaped without harm. Any escape sequence which matches a
 % single character (|\d|, |\D|, \emph{etc.}) is supported in character
 % classes.  If the first character is |^|, then
-% the meaning of the character class is inverted. Ranges of characters
+% the meaning of the character class is inverted; |^| appearing anywhere
+% else in the range is not special.  If the first character (possibly
+% following a leading |^|) is |]| then it does not need to be escaped
+% since ending the range there would make it empty.
+% Ranges of characters
 % can be expressed using |-|, for instance, |[\D 0-5]| and |[^6-9]| are
 % equivalent.
 %
@@ -712,7 +716,7 @@
 %<*package>
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
-\RequirePackage{l3tl-build, l3tl-analysis, l3flag, l3str}
+\RequirePackage{l3tl-build, l3tl-analysis, l3flag, l3str, l3str-convert}
 %</package>
 %    \end{macrocode}
 %
@@ -911,7 +915,7 @@
 %   This function makes showing regular expressions easier, and lets us
 %   define |\D| in terms of |\d| for instance. There is a subtelty: the
 %   end of the query is marked by $-2$, and will thus match |\D| and
-%   other negated properties; this case is catched by another part of
+%   other negated properties; this case is caught by another part of
 %   the code.
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_item_reverse:n #1
@@ -1375,7 +1379,7 @@
         {
           \__msg_kernel_error:nnx { regex } { x-overflow } {#1}
           \tl_set:Nx \l_@@_internal_b_tl
-            { \if_false: } \fi: \@@_escape_loop:N
+            { \if_false: } \fi:
         }
         {
           \char_set_lccode:nn { \c_zero } {#1}
@@ -1384,7 +1388,6 @@
               \tl_set:Nx \l_@@_internal_b_tl
                 { \if_false: } \fi:
                 \@@_escape_raw:N ^^@
-                \@@_escape_loop:N
             }
         }
     }
@@ -1414,7 +1417,7 @@
   }
 \cs_new:Npn \@@_escape_x_test_two:N #1
   {
-    \if_charcode:w \c_lbrace_str #1
+    \if_charcode:w \c_left_brace_str #1
       \exp_after:wN \@@_escape_x_loop:N
     \else:
       \__str_hexadecimal_use:NTF #1
@@ -1454,7 +1457,7 @@
           { \@@_escape_x_loop:N }
           {
             ;
-            \exp_after:wN \token_if_eq_charcode:NNTF \c_rbrace_str #1
+            \exp_after:wN \token_if_eq_charcode:NNTF \c_right_brace_str #1
               { \@@_escape_loop:N }
               {
                 \if_false: { \fi: }
@@ -1487,9 +1490,7 @@
 %   \end{itemize}
 %   The code is ugly, and highly based on magic numbers and the ascii
 %   codes of characters. This is mostly unavoidable for performance
-%   reasons: testing for instance with \cs{__str_if_contains_char:nN}
-%   would be much slower. Maybe the tests can be optimized a little
-%   bit more.
+%   reasons.  Maybe the tests can be optimized a little bit more.
 %   Here, \enquote{alphanumeric} means \texttt{0}--\texttt{9},
 %   \texttt{A}--\texttt{Z}, \texttt{a}--\texttt{z};
 %   \enquote{special} character means non-alphanumeric
@@ -2111,17 +2112,17 @@
 %   brace, leading to the range $[a,\infty]$ or $[a,b]$, encoded as
 %   $\{a\}\{-1\}$ and $\{a\}\{b-a\}$.
 %    \begin{macrocode}
-\cs_new_protected:cpn { @@_compile_quantifier_ \c_lbrace_str :w }
+\cs_new_protected:cpn { @@_compile_quantifier_ \c_left_brace_str :w }
   {
     \@@_get_digits:NTFw \l_@@_internal_a_int
       { \@@_compile_quantifier_braced_auxi:w }
-      { \@@_compile_quantifier_abort:xNN { \c_lbrace_str } }
+      { \@@_compile_quantifier_abort:xNN { \c_left_brace_str } }
   }
 \cs_new_protected:Npn \@@_compile_quantifier_braced_auxi:w #1#2
   {
     \str_case_x:nnn { #1 #2 }
       {
-        { \@@_compile_special:N \c_rbrace_str }
+        { \@@_compile_special:N \c_right_brace_str }
           {
             \exp_args:No \@@_compile_quantifier_lazyness:nnNN
               { \int_use:N \l_@@_internal_a_int } { 0 }
@@ -2135,28 +2136,28 @@
       }
       {
         \@@_compile_quantifier_abort:xNN
-          { \c_lbrace_str \int_use:N \l_@@_internal_a_int }
+          { \c_left_brace_str \int_use:N \l_@@_internal_a_int }
         #1 #2
       }
   }
 \cs_new_protected:Npn \@@_compile_quantifier_braced_auxii:w #1#2
   {
     \str_if_eq_x:nnTF
-      { #1 #2 } { \@@_compile_special:N \c_rbrace_str }
+      { #1 #2 } { \@@_compile_special:N \c_right_brace_str }
       {
         \exp_args:No \@@_compile_quantifier_lazyness:nnNN
           { \int_use:N \l_@@_internal_a_int } { -1 }
       }
       {
         \@@_compile_quantifier_abort:xNN
-          { \c_lbrace_str \int_use:N \l_@@_internal_a_int , }
+          { \c_left_brace_str \int_use:N \l_@@_internal_a_int , }
         #1 #2
       }
   }
 \cs_new_protected:Npn \@@_compile_quantifier_braced_auxiii:w #1#2
   {
     \str_if_eq_x:nnTF
-      { #1 #2 } { \@@_compile_special:N \c_rbrace_str }
+      { #1 #2 } { \@@_compile_special:N \c_right_brace_str }
       {
         \if_int_compare:w \l_@@_internal_a_int > \l_@@_internal_b_int
           \__msg_kernel_error:nnxx { regex } { backwards-quantifier }
@@ -2173,7 +2174,7 @@
       {
         \@@_compile_quantifier_abort:xNN
           {
-            \c_lbrace_str
+            \c_left_brace_str
             \int_use:N \l_@@_internal_a_int ,
             \int_use:N \l_@@_internal_b_int
           }
@@ -2856,7 +2857,7 @@
 %   to forbid nesting |\c|. Additionally, disable submatch tracking
 %   since groups don't escape the scope of |\c{...}|.
 %    \begin{macrocode}
-\cs_new_protected_nopar:cpn { @@_compile_c_ \c_lbrace_str :w }
+\cs_new_protected_nopar:cpn { @@_compile_c_ \c_left_brace_str :w }
   {
     \@@_compile:w
       \@@_disable_submatches:
@@ -2875,7 +2876,7 @@
 %   dangling class or group).  Then insert the corresponding test in the
 %   outer regex.
 %    \begin{macrocode}
-\cs_new_protected:cpn { @@_compile_ \c_rbrace_str : }
+\cs_new_protected:cpn { @@_compile_ \c_right_brace_str : }
   {
     \@@_if_in_cs:TF
       {
@@ -2883,7 +2884,7 @@
         \@@_compile_one:x
           { \@@_item_cs:n { \exp_not:o \l_@@_internal_regex } }
       }
-      { \exp_after:wN \@@_compile_raw:N \c_rbrace_str }
+      { \exp_after:wN \@@_compile_raw:N \c_right_brace_str }
   }
 %    \end{macrocode}
 % \end{macro}
@@ -2907,7 +2908,7 @@
     \@@_if_in_class_or_catcode:TF
       { \@@_compile_raw_error:N u #1 #2 }
       {
-        \str_if_eq_x:nnTF {#1#2} { \@@_compile_special:N \c_lbrace_str }
+        \str_if_eq_x:nnTF {#1#2} { \@@_compile_special:N \c_left_brace_str }
           {
             \tl_set:Nx \l_@@_internal_a_tl { \if_false: } \fi:
             \@@_compile_u_loop:NN
@@ -2925,7 +2926,7 @@
       {
         \token_if_eq_meaning:NNTF #1 \@@_compile_special:N
           {
-            \exp_after:wN \token_if_eq_charcode:NNTF \c_rbrace_str #2
+            \exp_after:wN \token_if_eq_charcode:NNTF \c_right_brace_str #2
               { \if_false: { \fi: } \@@_compile_u_end: }
               { #2 \@@_compile_u_loop:NN }
           }
@@ -4733,7 +4734,7 @@
       \tl_clear:N \l_@@_balance_tl
       \@@_escape_use:nnnn
         {
-          \if_charcode:w \c_rbrace_str ##1
+          \if_charcode:w \c_right_brace_str ##1
             \@@_replacement_rbrace:N \else: \__tl_build_one:n \fi: ##1
         }
         { \@@_replacement_escaped:N ##1 }
@@ -4820,7 +4821,7 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_replacement_g:w #1#2
   {
-    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_lbrace_str }
+    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_left_brace_str }
       {
         \int_zero:N \l_@@_internal_a_int
         \@@_replacement_g_digits:NN
@@ -4877,7 +4878,7 @@
       }
       { \@@_replacement_error:NNN c #1#2 }
   }
-\cs_new_protected_nopar:cpn { @@_replacement_c_ \c_lbrace_str :w }
+\cs_new_protected_nopar:cpn { @@_replacement_c_ \c_left_brace_str :w }
   {
     \if_case:w \l_@@_replacement_csnames_int
       \__tl_build_one:n
@@ -4898,7 +4899,7 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_replacement_u:w #1#2
   {
-    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_lbrace_str }
+    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_left_brace_str }
       {
         \if_case:w \l_@@_replacement_csnames_int
           \__tl_build_one:n { \exp_not:n { \exp_after:wN \exp_not:V \cs:w } }
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-convert.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-convert.dtx
new file mode 100644
index 00000000000..1810468ff7d
--- /dev/null
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-convert.dtx
@@ -0,0 +1,3623 @@
+% \iffalse meta-comment
+%
+%% File: l3str-convert.dtx Copyright (C) 2013 The LaTeX3 Project
+%%
+%% It may be distributed and/or modified under the conditions of the
+%% LaTeX Project Public License (LPPL), either version 1.3c of this
+%% license or (at your option) any later version.  The latest version
+%% of this license is in the file
+%%
+%%    http://www.latex-project.org/lppl.txt
+%%
+%% This file is part of the "l3experimental bundle" (The Work in LPPL)
+%% and all files in that bundle must be distributed together.
+%%
+%% The released version of this bundle is available from CTAN.
+%%
+%% -----------------------------------------------------------------------
+%%
+%% The development version of the bundle can be found at
+%%
+%%    http://www.latex-project.org/svnroot/experimental/trunk/
+%%
+%% for those people who are interested.
+%%
+%%%%%%%%%%%
+%% NOTE: %%
+%%%%%%%%%%%
+%%
+%%   Snapshots taken from the repository represent work in progress and may
+%%   not work or may contain conflicting material!  We therefore ask
+%%   people _not_ to put them into distributions, archives, etc. without
+%%   prior consultation with the LaTeX3 Project.
+%%
+%% -----------------------------------------------------------------------
+%
+%<*driver|package>
+\RequirePackage{expl3}
+\GetIdInfo$Id: l3str-convert.dtx 4339 2013-01-08 10:22:00Z bruno $
+  {L3 Experimental string encoding conversions}
+%</driver|package>
+%<*driver>
+\documentclass[full]{l3doc}
+\usepackage{amsmath}
+\begin{document}
+  \tableofcontents
+  \DocInput{\jobname.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+%
+% \title{^^A
+%   The \textsf{l3str-convert} package: string encoding conversions^^A
+%   \thanks{This file describes v\ExplFileVersion,
+%     last revised \ExplFileDate.}^^A
+% }
+%
+% \author{^^A
+%  The \LaTeX3 Project\thanks
+%    {^^A
+%      E-mail:
+%        \href{mailto:latex-team@latex-project.org}
+%          {latex-team@latex-project.org}^^A
+%    }^^A
+% }
+%
+% \date{Released \ExplFileDate}
+%
+% \maketitle
+%
+% \newcommand{\hexnum}[1]{\text{\texttt{\char`\"}#1}}
+% \begin{documentation}
+%
+% \section{Encoding and escaping schemes}
+%
+% Traditionally, string encodings only specify how strings of characters
+% should be stored as bytes. However, the resulting lists of bytes are
+% often to be used in contexts where only a restricted subset of bytes
+% are permitted (\emph{e.g.}, \textsc{pdf} string objects,
+% \textsc{url}s).  Hence, storing a string of characters is done in two
+% steps.
+% \begin{itemize}
+%   \item The code points (\enquote{character codes}) are expressed as
+%     bytes following a given \enquote{encoding}. This can be
+%     \textsc{utf-16}, \textsc{iso 8859-1}, \emph{etc.}  See
+%     Table~\ref{tab:encodings} for a list of supported
+%     encodings.\footnote{Encodings and escapings will be added as they
+%       are requested.}
+%   \item Bytes are translated to \TeX{} tokens through a given
+%     \enquote{escaping}. Those are defined for the most part by the
+%     \texttt{pdf} file format.  See Table~\ref{tab:escapings} for a
+%     list of escaping methods supported.\footnotemark
+% \end{itemize}
+%
+% \begin{table}\centering
+%   \caption{\label{tab:encodings}Supported encodings.
+%     Non-alphanumeric characters are ignored,
+%     and capital letters are lower-cased
+%     before searching for the encoding in this list.}
+%   \begin{tabular}{cc}
+%     \toprule
+%     \meta{Encoding}   & description \\
+%     \midrule
+%     \texttt{utf8}     & \textsc{utf-8} \\
+%     \texttt{utf16}    & \textsc{utf-16}, with byte-order mark \\
+%     \texttt{utf16be}  & \textsc{utf-16}, big-endian \\
+%     \texttt{utf16le}  & \textsc{utf-16}, little-endian \\
+%     \texttt{utf32}    & \textsc{utf-32}, with byte-order mark \\
+%     \texttt{utf32be}  & \textsc{utf-32}, big-endian \\
+%     \texttt{utf32le}  & \textsc{utf-32}, little-endian \\
+%     \midrule
+%     \texttt{iso88591},  \texttt{latin1}  & \textsc{iso 8859-1} \\
+%     \texttt{iso88592},  \texttt{latin2}  & \textsc{iso 8859-2} \\
+%     \texttt{iso88593},  \texttt{latin3}  & \textsc{iso 8859-3} \\
+%     \texttt{iso88594},  \texttt{latin4}  & \textsc{iso 8859-4} \\
+%     \texttt{iso88595}                    & \textsc{iso 8859-5} \\
+%     \texttt{iso88596}                    & \textsc{iso 8859-6} \\
+%     \texttt{iso88597}                    & \textsc{iso 8859-7} \\
+%     \texttt{iso88598}                    & \textsc{iso 8859-8} \\
+%     \texttt{iso88599},  \texttt{latin5}  & \textsc{iso 8859-9} \\
+%     \texttt{iso885910}, \texttt{latin6}  & \textsc{iso 8859-10} \\
+%     \texttt{iso885911}                   & \textsc{iso 8859-11} \\
+%     \texttt{iso885913}, \texttt{latin7}  & \textsc{iso 8859-13} \\
+%     \texttt{iso885914}, \texttt{latin8}  & \textsc{iso 8859-14} \\
+%     \texttt{iso885915}, \texttt{latin9}  & \textsc{iso 8859-15} \\
+%     \texttt{iso885916}, \texttt{latin10} & \textsc{iso 8859-16} \\
+%     \midrule
+%     Empty & Native (Unicode) string. \\
+%     \bottomrule
+%   \end{tabular}
+% \end{table}
+%
+% \begin{table}\centering
+%   \caption{\label{tab:escapings}Supported escapings.
+%     Non-alphanumeric characters are ignored,
+%     and capital letters are lower-cased
+%     before searching for the escaping in this list.}
+%   \begin{tabular}{cc}
+%     \toprule
+%     \meta{Escaping} & description \\
+%     \midrule
+%     \texttt{bytes}, or empty
+%       & arbitrary bytes \\
+%     \texttt{hex}, \texttt{hexadecimal}
+%       & byte $=$ two hexadecimal digits \\
+%     \texttt{name}
+%       & see \tn{pdfescapename} \\
+%     \texttt{string}
+%       & see \tn{pdfescapestring} \\
+%     \texttt{url}
+%       & encoding used in \textsc{url}s \\
+%     \bottomrule
+%   \end{tabular}
+% \end{table}
+%
+% \section{Conversion functions}
+%
+% \begin{function}{\str_set_convert:Nnnn, \str_gset_convert:Nnnn}
+%   \begin{syntax}
+%     \cs{str_set_convert:Nnnn} \meta{str~var} \Arg{string} \Arg{name~1} \Arg{name~2}
+%   \end{syntax}
+%   This function converts the \meta{string} from the encoding given by
+%   \meta{name~1} to the encoding given by \meta{name~2}, and stores the
+%   result in the \meta{str~var}.  Each \meta{name} can have the form
+%   \meta{encoding} or \meta{encoding}\texttt{/}\meta{escaping}, where
+%   the possible values of \meta{encoding} and \meta{escaping} are given
+%   in Tables~\ref{tab:encodings} and~\ref{tab:escapings}, respectively.
+%   The default escaping is to input and output bytes directly.  The
+%   special case of an empty \meta{name} indicates the use of
+%   \enquote{native} strings, 8-bit for pdf\TeX{}, and Unicode strings
+%   for the other two engines.
+%
+%   For example,
+%   \begin{verbatim}
+%     \str_set_convert:Nnnn \l_foo_str { Hello! } { } { utf16/hex }
+%   \end{verbatim}
+%   results in the variable \cs{l_foo_str} holding the string
+%   \texttt{FEFF00480065006C006C006F0021}. This is obtained by
+%   converting each character in the (native) string \texttt{Hello!}  to
+%   the \textsc{utf-16} encoding, and expressing each byte as a pair of
+%   hexadecimal digits. Note the presence of a (big-endian) byte order
+%   mark \hexnum{FEFF}, which can be avoided by specifying the encoding
+%   \texttt{utf16be/hex}.
+%
+%   An error is raised if the \meta{string} is not valid according to
+%   the \meta{escaping~1} and \meta{encoding~1}, or if it cannot be
+%   reencoded in the \meta{encoding~2} and \meta{escaping~2} (for
+%   instance, if a character does not exist in the \meta{encoding~2}).
+%   Erroneous input is replaced by the Unicode replacement character
+%   \hexnum{FFFD}, and characters which cannot be reencoded are replaced
+%   by either the replacement character \hexnum{FFFD} if it exists in
+%   the \meta{encoding~2}, or an encoding-specific replacement
+%   character, or the question mark character.
+% \end{function}
+%
+% \begin{function}[TF]{\str_set_convert:Nnnn, \str_gset_convert:Nnnn}
+%   \begin{syntax}
+%     \cs{str_set_convert:NnnnTF} \meta{str~var} \Arg{string} \Arg{name~1} \Arg{name~2} \Arg{true code} \Arg{false code}
+%   \end{syntax}
+%   As \cs{str_set_convert:Nnnn}, converts the \meta{string} from the
+%   encoding given by \meta{name~1} to the encoding given by
+%   \meta{name~2}, and assigns the result to \meta{str~var}. Contrarily
+%   to \cs{str_set_convert:Nnnn}, the conditional variant does not raise
+%   errors in case the \meta{string} is not valid according to the
+%   \meta{name~1} encoding, or cannot be expressed in the \meta{name~2}
+%   encoding. Instead, the \meta{false code} is performed.
+% \end{function}
+%
+% \begin{variable}{\c_max_char_int}
+%   The maximum valid character code, $255$ for pdf\TeX{}, and $1114111$
+%   for \XeTeX{} and \LuaTeX{}.
+% \end{variable}
+%
+% \section{Internal string functions}
+%
+% \begin{function}{\__str_gset_other:Nn}
+%   \begin{syntax}
+%     \cs{__str_gset_other:Nn} \meta{tl~var} \Arg{token list}
+%   \end{syntax}
+%   Converts the \meta{token list} to an \meta{other string}, where
+%   spaces have category code \enquote{other}, and assigns the result to
+%   the \meta{tl~var}, globally.
+% \end{function}
+%
+% \begin{function}{\__str_hexadecimal_use:NTF}
+%   \begin{syntax}
+%     \cs{__str_hexadecimal_use:NTF} \meta{token} \Arg{true code} \Arg{false code}
+%   \end{syntax}
+%   If the \meta{token} is a hexadecimal digit (upper case or lower
+%   case), its upper-case version is left in the input stream,
+%   \emph{followed} by the \meta{true code}. Otherwise, the \meta{false
+%     code} is left in the input stream.
+%   \begin{texnote}
+%     This function fails on some inputs if the escape character is a
+%     hexadecimal digit.  We are thus careful to set the escape
+%     character to a known (safe) value before using it.
+%   \end{texnote}
+% \end{function}
+%
+% \begin{function}[EXP]{\__str_output_byte:n}
+%   \begin{syntax}
+%     \cs{__str_output_byte:n} \Arg{intexpr}
+%   \end{syntax}
+%   Expands to a character token with category other and character code
+%   equal to the value of \meta{intexpr}.  The value of \meta{intexpr}
+%   must be in the range $[-1, 255]$, and any value outside this range
+%   results in undefined behaviour.  The special value $-1$ is used to
+%   produce an empty result.
+% \end{function}
+%
+% \section{Possibilities, and things to do}
+%
+% Encoding/escaping-related tasks.
+% \begin{itemize}
+%   \item Describe the internal format in the code comments. Refuse code
+%     points in $[\hexnum{D800}, \hexnum{DFFF}]$ in the internal
+%     representation?
+%   \item Add documentation about each encoding and escaping method, and
+%     add examples.
+%   \item The \texttt{hex} unescaping should raise an error for
+%     odd-token count strings.
+%   \item Decide what bytes should be escaped in the \texttt{url}
+%     escaping. Perhaps |!'()*-./0123456789_| are safe, and all other
+%     characters should be escaped?
+%   \item Automate generation of 8-bit mapping files.
+%   \item Change the framework for 8-bit encodings: for decoding from
+%     8-bit to Unicode, use $256$ integer registers; for encoding, use a
+%     tree-box.
+%   \item More encodings (see Heiko's \pkg{stringenc}). CESU?
+%   \item More escapings: shell escapes, lua escapes, etc?
+% \end{itemize}
+%
+% \end{documentation}
+%
+% \begin{implementation}
+%
+% \section{\pkg{l3str} implementation}
+%
+%    \begin{macrocode}
+%<*initex|package>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<@@=str>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\ProvidesExplPackage
+  {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
+\RequirePackage{l3str,l3tl-analysis,l3tl-build,l3flag}
+%    \end{macrocode}
+%
+% \subsection{Helpers}
+%
+% \subsubsection{A function unrelated to strings}
+%
+% \begin{macro}[EXP,aux]{\use_ii_i:nn}
+%   A function used to swap its arguments.
+%    \begin{macrocode}
+\cs_if_exist:NF \use_ii_i:nn
+  { \cs_new:Npn \use_ii_i:nn #1#2 { #2 #1 } }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Variables and constants}
+%
+% \begin{variable}{\c_max_char_int}
+%   The maximum valid character code is $255$ for pdf\TeX{}, and
+%   $1114111$ for other engines.
+%    \begin{macrocode}
+\int_const:Nn \c_max_char_int
+  { \pdftex_if_engine:TF { "FF } { "10FFFF } }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_tmp:w}
+% \begin{variable}{\l_@@_internal_int}
+% \begin{variable}{\l_@@_internal_tl}
+%   Internal scratch space for some functions.
+%    \begin{macrocode}
+\cs_new_protected_nopar:Npn \@@_tmp:w { }
+\tl_new:N \l_@@_internal_tl
+\int_new:N \l_@@_internal_int
+%    \end{macrocode}
+% \end{variable}
+% \end{variable}
+% \end{macro}
+%
+% \begin{variable}{\g_@@_result_tl}
+%   The \cs{g_@@_result_tl} variable is used to hold the result of
+%   various internal string operations (mostly conversions) which are
+%   typically performed in a group. The variable is global so that it
+%   remains defined outside the group, to be assigned to a user-provided
+%   variable.
+%    \begin{macrocode}
+\tl_new:N \g_@@_result_tl
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\c_@@_replacement_char_int}
+%   When converting, invalid bytes are replaced by the Unicode
+%   replacement character \hexnum{FFFD}.
+%    \begin{macrocode}
+\int_const:Nn \c_@@_replacement_char_int { "FFFD }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}
+%   {
+%     \c_forty_eight, \c_fifty_eight, \c_sixty_five, \c_ninety_one,
+%     \c_ninety_seven, \c_one_hundred_twenty_three,
+%     \c_one_hundred_twenty_seven
+%   }
+%   We declare here some integer values which delimit ranges of \textsc{ascii}
+%   characters of various types. This is mostly used in \pkg{l3regex}.
+%    \begin{macrocode}
+\int_const:Nn \c_forty_eight  { 48 }
+\int_const:Nn \c_fifty_eight  { 58 }
+\int_const:Nn \c_sixty_five   { 65 }
+\int_const:Nn \c_ninety_one   { 91 }
+\int_const:Nn \c_ninety_seven { 97 }
+\int_const:Nn \c_one_hundred_twenty_three { 123 }
+\int_const:Nn \c_one_hundred_twenty_seven { 127 }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_alias_prop}
+%   To avoid needing one file per encoding/escaping alias, we keep track
+%   of those in a property list.
+%    \begin{macrocode}
+\prop_new:N \g_@@_alias_prop
+\prop_gput:Nnn \g_@@_alias_prop { latin1 } { iso88591 }
+\prop_gput:Nnn \g_@@_alias_prop { latin2 } { iso88592 }
+\prop_gput:Nnn \g_@@_alias_prop { latin3 } { iso88593 }
+\prop_gput:Nnn \g_@@_alias_prop { latin4 } { iso88594 }
+\prop_gput:Nnn \g_@@_alias_prop { latin5 } { iso88599 }
+\prop_gput:Nnn \g_@@_alias_prop { latin6 } { iso885910 }
+\prop_gput:Nnn \g_@@_alias_prop { latin7 } { iso885913 }
+\prop_gput:Nnn \g_@@_alias_prop { latin8 } { iso885914 }
+\prop_gput:Nnn \g_@@_alias_prop { latin9 } { iso885915 }
+\prop_gput:Nnn \g_@@_alias_prop { latin10 } { iso885916 }
+\prop_gput:Nnn \g_@@_alias_prop { utf16le } { utf16 }
+\prop_gput:Nnn \g_@@_alias_prop { utf16be } { utf16 }
+\prop_gput:Nnn \g_@@_alias_prop { utf32le } { utf32 }
+\prop_gput:Nnn \g_@@_alias_prop { utf32be } { utf32 }
+\prop_gput:Nnn \g_@@_alias_prop { hexadecimal } { hex }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_error_bool}
+%   In conversion functions with a built-in conditional, errors are not
+%   reported directly to the user, but the information is collected in
+%   this boolean, used at the end to decide on which branch of the
+%   conditional to take.
+%    \begin{macrocode}
+\bool_new:N \g_@@_error_bool
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{str_byte, str_error}
+%   Conversions from one \meta{encoding}/\meta{escaping} pair to another
+%   are done within \texttt{x}-expanding assignments. Errors are
+%   signalled by raising the relevant flag.
+%    \begin{macrocode}
+\flag_new:n { str_byte }
+\flag_new:n { str_error }
+%    \end{macrocode}
+% \end{variable}
+%
+% \subsubsection{Escaping spaces}
+%
+% \begin{macro}[int]{\@@_gset_other:Nn}
+% \begin{macro}[aux,EXP]{\@@_gset_other_loop:w}
+% \begin{macro}[aux,EXP]{\@@_gset_other_end:w}
+%   This function could be done by using \cs{@@_to_other:n} within
+%   an \texttt{x}-expansion, but that would take a time quadratic in the
+%   size of the string. Instead, we can \enquote{leave the result behind
+%     us} in the input stream, to be captured into the expanding
+%   assignment. This gives us a linear time.
+%    \begin{macrocode}
+\group_begin:
+\char_set_lccode:nn { `\* } { `\  }
+\char_set_lccode:nn { `\A } { `\A }
+\tl_to_lowercase:n
+  {
+    \group_end:
+    \cs_new_protected:Npn \@@_gset_other:Nn #1#2
+      {
+        \tl_gset:Nx #1
+          {
+            \exp_after:wN \@@_gset_other_loop:w \tl_to_str:n {#2} ~ %
+            A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_stop
+          }
+      }
+    \cs_new:Npn \@@_gset_other_loop:w
+      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 ~
+      {
+        \if_meaning:w A #9
+          \@@_gset_other_end:w
+        \fi:
+        #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * #9
+        \@@_gset_other_loop:w *
+      }
+    \cs_new:Npn \@@_gset_other_end:w \fi: #1 * A #2 \q_stop
+      { \fi: #1 }
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{String conditionals}
+%
+% \begin{macro}[EXP]{\@@_if_contains_char:NNT, \@@_if_contains_char:NNTF}
+% \begin{macro}[EXP]{\@@_if_contains_char:nNTF}
+% \begin{macro}[EXP,aux]{\@@_if_contains_char_aux:NN}
+% \begin{macro}[EXP,aux]{\@@_if_contains_char_true:}
+%   \begin{syntax}
+%     \cs{@@_if_contains_char:nNTF} \Arg{token list} \meta{char}
+%   \end{syntax}
+%   Expects the \meta{token list} to be an \meta{other string}: the
+%   caller is responsible for ensuring that no (too-)special catcodes
+%   remain.  Spaces with catcode $10$ are ignored.
+%   Loop over the characters of the string, comparing character codes.
+%   The loop is broken if character codes match. Otherwise we return
+%   \enquote{false}.
+%    \begin{macrocode}
+\prg_new_conditional:Npnn \@@_if_contains_char:NN #1#2 { T , TF }
+  {
+    \exp_after:wN \@@_if_contains_char_aux:NN \exp_after:wN #2
+      #1 { \__prg_break:n { ? \fi: } }
+    \__prg_break_point:
+    \prg_return_false:
+  }
+\prg_new_conditional:Npnn \@@_if_contains_char:nN #1#2 { TF }
+  {
+    \@@_if_contains_char_aux:NN #2 #1 { \__prg_break:n { ? \fi: } }
+    \__prg_break_point:
+    \prg_return_false:
+  }
+\cs_new:Npn \@@_if_contains_char_aux:NN #1#2
+  {
+    \if_charcode:w #1 #2
+      \exp_after:wN \@@_if_contains_char_true:
+    \fi:
+    \@@_if_contains_char_aux:NN #1
+  }
+\cs_new_nopar:Npn \@@_if_contains_char_true:
+  { \__prg_break:n { \prg_return_true: \use_none:n } }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[aux, rEXP]{\@@_octal_use:NTF}
+%   \begin{syntax}
+%     \cs{@@_octal_use:NTF} \meta{token} \Arg{true code} \Arg{false code}
+%   \end{syntax}
+%   If the \meta{token} is an octal digit, it is left in the input
+%   stream, \emph{followed} by the \meta{true code}. Otherwise, the
+%   \meta{false code} is left in the input stream.
+%   \begin{texnote}
+%     This function will fail if the escape character is an octal
+%     digit. We are thus careful to set the escape character to a known
+%     value before using it.
+%   \end{texnote}
+%   \TeX{} dutifully detects octal digits for us: if |#1| is an octal
+%   digit, then the right-hand side of the comparison is |'1#1|, greater
+%   than $1$. Otherwise, the right-hand side stops as |'1|, and the
+%   conditional takes the \texttt{false} branch.
+%    \begin{macrocode}
+\prg_new_conditional:Npnn \@@_octal_use:N #1 { TF }
+  {
+    \if_int_compare:w \c_one < '1 \token_to_str:N #1 \exp_stop_f:
+      #1 \prg_return_true:
+    \else:
+      \prg_return_false:
+    \fi:
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[aux, rEXP]{\@@_hexadecimal_use:NTF}
+%   \TeX{} detects uppercase hexadecimal digits for us (see
+%   \cs{@@_octal_use:NTF}), but not the lowercase letters, which we
+%   need to detect and replace by their uppercase counterpart.
+%    \begin{macrocode}
+\prg_new_conditional:Npnn \@@_hexadecimal_use:N #1 { TF }
+  {
+    \if_int_compare:w \c_two < "1 \token_to_str:N #1 \exp_stop_f:
+      #1 \prg_return_true:
+    \else:
+      \if_case:w \__int_eval:w
+          \exp_after:wN ` \token_to_str:N #1 - `a
+        \__int_eval_end:
+           A
+      \or: B
+      \or: C
+      \or: D
+      \or: E
+      \or: F
+      \else:
+        \prg_return_false:
+        \exp_after:wN \use_none:n
+      \fi:
+      \prg_return_true:
+    \fi:
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Conversions}
+%
+% \subsubsection{Producing one byte or character}
+%
+% \begin{variable}{\c_@@_byte_0_tl, \c_@@_byte_1_tl, \c_@@_byte_255_tl}
+% \begin{variable}{\c_@@_byte_-1_tl}
+%   For each integer $N$ in the range $[0,255]$, we create a constant
+%   token list which holds three character tokens with category code
+%   other: the character with character code $N$, followed by the
+%   representation of $N$ as two hexadecimal digits.  The value $-1$ is
+%   given a default token list which ensures that later functions give
+%   an empty result for the input $-1$.
+%    \begin{macrocode}
+\group_begin:
+  \char_set_catcode_other:n { \c_zero }
+  \tl_set:Nx \l_@@_internal_tl { \tl_to_str:n { 0123456789ABCDEF } }
+  \exp_args:No \tl_map_inline:nn { \l_@@_internal_tl " }
+    { \char_set_lccode:nn {`#1} { \c_zero } }
+  \tl_map_inline:Nn \l_@@_internal_tl
+    {
+      \tl_map_inline:Nn \l_@@_internal_tl
+        {
+          \char_set_lccode:nn { \c_zero } {"#1##1}
+          \tl_to_lowercase:n
+            {
+              \tl_const:cx
+                { c_@@_byte_ \int_eval:n {"#1##1} _tl }
+                { ^^@ #1 ##1 }
+            }
+        }
+    }
+\group_end:
+\tl_const:cn { c_@@_byte_-1_tl } { { } \use_none:n { } }
+%    \end{macrocode}
+% \end{variable}
+% \end{variable}
+%
+% \begin{macro}[int, EXP]{\@@_output_byte:n}
+% \begin{macro}[int, EXP]{\@@_output_byte:w}
+% \begin{macro}[int, EXP]{\@@_output_hexadecimal:n}
+% \begin{macro}[int, EXP]{\@@_output_hexadecimal:w}
+% \begin{macro}[int, EXP]{\@@_output_end:}
+%   Those functions must be used carefully: feeding them a value outside
+%   the range $[-1,255]$ will attempt to use the undefined token list
+%   variable \cs{c_@@_byte_\meta{number}_tl}. Assuming that the
+%   argument is in the right range, we expand the corresponding token
+%   list, and pick either the byte (first token) or the hexadecimal
+%   representations (second and third tokens). The value $-1$ produces
+%   an empty result in both cases.
+%    \begin{macrocode}
+\cs_new:Npn \@@_output_byte:n #1
+  { \@@_output_byte:w #1 \@@_output_end: }
+\cs_new_nopar:Npn \@@_output_byte:w
+  {
+    \exp_after:wN \exp_after:wN
+    \exp_after:wN \use_i:nnn
+    \cs:w c_@@_byte_ \int_use:N \__int_eval:w
+  }
+\cs_new:Npn \@@_output_hexadecimal:n #1
+  { \@@_output_hexadecimal:w #1 \@@_output_end: }
+\cs_new_nopar:Npn \@@_output_hexadecimal:w
+  {
+    \exp_after:wN \exp_after:wN
+    \exp_after:wN \use_none:n
+    \cs:w c_@@_byte_ \int_use:N \__int_eval:w
+  }
+\cs_new_nopar:Npn \@@_output_end:
+  { \__int_eval_end: _tl \cs_end: }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int, rEXP]{\@@_output_byte_pair_be:n}
+% \begin{macro}[int, rEXP]{\@@_output_byte_pair_le:n}
+% \begin{macro}[aux, rEXP]{\@@_output_byte_pair:nnN}
+%   Convert a number in the range $[0,65535]$ to a pair of bytes, either
+%   big-endian or little-endian.
+%    \begin{macrocode}
+\cs_new:Npn \@@_output_byte_pair_be:n #1
+  {
+    \exp_args:Nf \@@_output_byte_pair:nnN
+      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use:nn
+  }
+\cs_new:Npn \@@_output_byte_pair_le:n #1
+  {
+    \exp_args:Nf \@@_output_byte_pair:nnN
+      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use_ii_i:nn
+  }
+\cs_new:Npn \@@_output_byte_pair:nnN #1#2#3
+  {
+    #3
+      { \@@_output_byte:n { #1 } }
+      { \@@_output_byte:n { #2 - #1 * "100 } }
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Mapping functions for conversions}
+%
+% \begin{macro}{\@@_convert_gmap:N}
+% \begin{macro}[aux, rEXP]{\@@_convert_gmap_loop:NN}
+%   This maps the function |#1| over all characters in
+%   \cs{g_@@_result_tl}, which should be a byte string in most cases,
+%   sometimes a native string.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_convert_gmap:N #1
+  {
+    \tl_gset:Nx \g_@@_result_tl
+      {
+        \exp_after:wN \@@_convert_gmap_loop:NN
+        \exp_after:wN #1
+          \g_@@_result_tl { ? \__prg_break: }
+        \__prg_break_point:
+      }
+  }
+\cs_new:Npn \@@_convert_gmap_loop:NN #1#2
+  {
+    \use_none:n #2
+    #1#2
+    \@@_convert_gmap_loop:NN #1
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_convert_gmap_internal:N}
+% \begin{macro}[aux, rEXP]{\@@_convert_gmap_internal_loop:Nw}
+%   This maps the function |#1| over all character codes in
+%   \cs{g_@@_result_tl}, which must be in the internal representation.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_convert_gmap_internal:N #1
+  {
+    \tl_gset:Nx \g_@@_result_tl
+      {
+        \exp_after:wN \@@_convert_gmap_internal_loop:Nww
+        \exp_after:wN #1
+          \g_@@_result_tl \s__tl \q_stop \__prg_break: \s__tl
+        \__prg_break_point:
+      }
+  }
+\cs_new:Npn \@@_convert_gmap_internal_loop:Nww #1 #2 \s__tl #3 \s__tl
+  {
+    \use_none_delimit_by_q_stop:w #3 \q_stop
+    #1 {#3}
+    \@@_convert_gmap_internal_loop:Nww #1
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Error-reporting during conversion}
+%
+% \begin{macro}[int]{\@@_if_flag_error:nnx}
+% \begin{macro}[aux]{\@@_if_flag_no_error:nnx}
+%   When converting using the function \cs{str_set_convert:Nnnn}, errors
+%   should be reported to the user after each step in the
+%   conversion. Errors are signalled by raising some flag (typically
+%   \texttt{@@_error}), so here we test that flag: if it is raised,
+%   give the user an error, otherwise remove the arguments. On the other
+%   hand, in the conditional functions \cs{str_set_convert:NnnnTF},
+%   errors should be suppressed. This is done by changing
+%   \cs{@@_if_flag_error:nnx} into \cs{@@_if_flag_no_error:nnx}
+%   locally.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_if_flag_error:nnx #1
+  {
+    \flag_if_raised:nTF {#1}
+      { \__msg_kernel_error:nnx { str } }
+      { \use_none:nn }
+  }
+\cs_new_protected:Npn \@@_if_flag_no_error:nnx #1#2#3
+  { \flag_if_raised:nT {#1} { \bool_gset_true:N \g_@@_error_bool } }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_if_flag_times:nT}
+%   At the end of each conversion step, we raise all relevant errors as
+%   one error message, built on the fly. The height of each flag
+%   indicates how many times a given error was encountered. This
+%   function prints |#2| followed by the number of occurrences of an
+%   error if it occurred, nothing otherwise.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_if_flag_times:nT #1#2
+  { \flag_if_raised:nT {#1} { #2~(x \flag_height:n {#1} ) } }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Framework for conversions}
+%
+% Most functions in this module expect to be working with
+% \enquote{native} strings. Strings can also be stored as bytes, in one
+% of many encodings, for instance \textsc{utf8}.  The bytes themselves
+% can be expressed in various ways in terms of \TeX{} tokens, for
+% instance as pairs of hexadecimal digits. The questions of going from
+% arbitrary Unicode code points to bytes, and from bytes to tokens are
+% mostly independent.
+%
+% Conversions are done in four steps:
+% \begin{itemize}
+%   \item \enquote{unescape} produces a string of bytes;
+%   \item \enquote{decode} takes in a string of bytes, and converts it
+%     to a list of Unicode characters in an internal representation,
+%     with items of the form
+%     \begin{quote}
+%       \meta{bytes} \cs{s__tl} \meta{Unicode code point} \cs{s__tl}
+%     \end{quote}
+%     where we have collected the \meta{bytes} which combined to form
+%     this particular Unicode character, and the \meta{Unicode code
+%       point} is in the range $[0,\hexnum{10FFFF}]$.
+%   \item \enquote{encode} encodes the internal list of code points as a
+%     byte string in the new encoding;
+%   \item \enquote{escape} escapes bytes as requested.
+% \end{itemize}
+% The process is modified in case one of the encoding is empty (or the
+% conversion function has been set equal to the empty encoding because
+% it was not found): then the unescape or escape step is ignored, and
+% the decode or encode steps work on tokens instead of bytes. Otherwise,
+% each step must ensure that it passes a correct byte string or internal
+% string to the next step.
+%
+% \begin{macro}{\str_set_convert:Nnnn, \str_gset_convert:Nnnn}
+% \begin{macro}[TF]{\str_set_convert:Nnnn, \str_gset_convert:Nnnn}
+% \begin{macro}[aux]{\@@_convert:nNNnnn}
+%   The input string is stored in \cs{g_@@_result_tl}, then we:
+%   unescape and decode; encode and escape; exit the group and store the
+%   result in the user's variable. The various conversion functions all
+%   act on \cs{g_@@_result_tl}. Errors are silenced for the conditional
+%   functions by redefining \cs{@@_if_flag_error:nnx} locally.
+%    \begin{macrocode}
+\cs_new_protected_nopar:Npn \str_set_convert:Nnnn
+  { \@@_convert:nNNnnn { } \tl_set_eq:NN }
+\cs_new_protected_nopar:Npn \str_gset_convert:Nnnn
+  { \@@_convert:nNNnnn { } \tl_gset_eq:NN }
+\prg_new_protected_conditional:Npnn
+    \str_set_convert:Nnnn #1#2#3#4 { T , F , TF }
+  {
+    \bool_gset_false:N \g_@@_error_bool
+    \@@_convert:nNNnnn
+      { \cs_set_eq:NN \@@_if_flag_error:nnx \@@_if_flag_no_error:nnx }
+      \tl_set_eq:NN #1 {#2} {#3} {#4}
+    \bool_if:NTF \g_@@_error_bool \prg_return_false: \prg_return_true:
+  }
+\prg_new_protected_conditional:Npnn
+    \str_gset_convert:Nnnn #1#2#3#4 { T , F , TF }
+  {
+    \bool_gset_false:N \g_@@_error_bool
+    \@@_convert:nNNnnn
+      { \cs_set_eq:NN \@@_if_flag_error:nnx \@@_if_flag_no_error:nnx }
+      \tl_gset_eq:NN #1 {#2} {#3} {#4}
+    \bool_if:NTF \g_@@_error_bool \prg_return_false: \prg_return_true:
+  }
+\cs_new_protected:Npn \@@_convert:nNNnnn #1#2#3#4#5#6
+  {
+    \group_begin:
+      #1
+      \@@_gset_other:Nn \g_@@_result_tl {#4}
+      \exp_after:wN \@@_convert:wwwnn
+        \tl_to_str:n {#5} /// \q_stop
+        { decode } { unescape }
+        \prg_do_nothing:
+        \@@_convert_decode_:
+      \exp_after:wN \@@_convert:wwwnn
+        \tl_to_str:n {#6} /// \q_stop
+        { encode } { escape }
+        \use_ii_i:nn
+        \@@_convert_encode_:
+    \group_end:
+    #2 #3 \g_@@_result_tl
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[aux]{\@@_convert:wwwnn}
+% \begin{macro}[aux]{\@@_convert:NNnNN}
+%   The task of \cs{@@_convert:wwwnn} is to split
+%   \meta{encoding}/\meta{escaping} pairs into their components, |#1|
+%   and |#2|. Calls to \cs{@@_convert:nnn} ensure that the
+%   corresponding conversion functions are defined. The third auxiliary
+%   does the main work.
+%   \begin{itemize}
+%     \item |#1| is the encoding conversion function;
+%     \item |#2| is the escaping function;
+%     \item |#3| is the escaping name for use in an error message;
+%     \item |#4| is \cs{prg_do_nothing:} for unescaping/decoding, and
+%       \cs{use_ii_i:nn} for encoding/escaping;
+%     \item |#5| is the default encoding function (either
+%       \enquote{decode} or \enquote{encode}), for which there should be
+%       no escaping.
+%   \end{itemize}
+%   Let us ignore the native encoding for a second. In the
+%   unescaping/decoding phase, we want to do |#2#1| in this order, and
+%   in the encoding/escaping phase, the order should be reversed:
+%   |#4#2#1| does exactly that. If one of the encodings is the default
+%   (native), then the escaping should be ignored, with an error if any
+%   was given, and only the encoding, |#1|, should be performed.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_convert:wwwnn
+    #1 / #2 // #3 \q_stop #4#5
+  {
+    \@@_convert:nnn {enc} {#4} {#1}
+    \@@_convert:nnn {esc} {#5} {#2}
+    \exp_args:Ncc \@@_convert:NNnNN
+      { @@_convert_#4_#1: } { @@_convert_#5_#2: } {#2}
+  }
+\cs_new_protected:Npn \@@_convert:NNnNN #1#2#3#4#5
+  {
+    \if_meaning:w #1 #5
+      \tl_if_empty:nF {#3}
+        { \__msg_kernel_error:nnx { str } { native-escaping } {#3} }
+      #1
+    \else:
+      #4 #2 #1
+    \fi:
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[aux]{\@@_convert:nnn}
+% \begin{macro}[aux]{\@@_convert:nnnn}
+%   The arguments of \cs{@@_convert:nnn} are: \texttt{enc} or
+%   \texttt{esc}, used to build filenames, the type of the conversion
+%   (unescape, decode, encode, escape), and the encoding or escaping
+%   name. If the function is already defined, no need to do anything.
+%   Otherwise, filter out all non-alphanumerics in the name, and
+%   lowercase it. Feed that, and the same three arguments, to
+%   \cs{@@_convert:nnnn}. The task is then to make sure that the
+%   conversion function |#3_#1| corresponding to the type |#3| and
+%   filtered name |#1| is defined, then set our initial conversion
+%   function |#3_#4| equal to that.
+%
+%   How do we get the |#3_#1| conversion to be defined if it isn't?
+%   Two main cases.
+%
+%   First, if |#1| is a key in \cs{g_@@_alias_prop}, then the value
+%   \cs{l_@@_internal_tl} tells us what file to load. Loading is
+%   skipped if the file was already read, \emph{i.e.}, if the conversion
+%   command based on \cs{l_@@_internal_tl} already exists.  Otherwise,
+%   try to load the file; if that fails, there is an error, use the
+%   default empty name instead.
+%
+%   Second, |#1| may be absent from the property list. The
+%   \cs{cs_if_exist:cF} test is automatically false, and we search for a
+%   file defining the encoding or escaping |#1| (this should allow
+%   third-party \texttt{.def} files). If the file is not found, there is
+%   an error, use the default empty name instead.
+%
+%   In all cases, the conversion based on \cs{l_@@_internal_tl} is
+%   defined, so we can set the |#3_#1| function equal to that. In some
+%   cases (\emph{e.g.}, \texttt{utf16be}), the |#3_#1| function is
+%   actually defined within the file we just loaded, and it is different
+%   from the \cs{l_@@_internal_tl}-based function: we mustn't clobber
+%   that different definition.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_convert:nnn #1#2#3
+  {
+    \cs_if_exist:cF { @@_convert_#2_#3: }
+      {
+        \exp_args:Nx \@@_convert:nnnn
+          { \@@_convert_lowercase_alphanum:n {#3} }
+          {#1} {#2} {#3}
+      }
+  }
+\cs_new_protected:Npn \@@_convert:nnnn #1#2#3#4
+  {
+    \cs_if_exist:cF { @@_convert_#3_#1: }
+      {
+        \prop_get:NnNF \g_@@_alias_prop {#1} \l_@@_internal_tl
+          { \tl_set:Nn \l_@@_internal_tl {#1} }
+        \cs_if_exist:cF { @@_convert_#3_ \l_@@_internal_tl : }
+          {
+            \file_if_exist:nTF { l3str-#2- \l_@@_internal_tl .def }
+              {
+                \group_begin:
+                  \@@_load_catcodes:
+                  \file_input:n { l3str-#2- \l_@@_internal_tl .def }
+                \group_end:
+              }
+              {
+                \tl_clear:N \l_@@_internal_tl
+                \__msg_kernel_error:nnxx { str } { unknown-#2 } {#4} {#1}
+              }
+          }
+        \cs_if_exist:cF { @@_convert_#3_#1: }
+          {
+            \cs_gset_eq:cc { @@_convert_#3_#1: }
+              { @@_convert_#3_ \l_@@_internal_tl : }
+          }
+      }
+    \cs_gset_eq:cc { @@_convert_#3_#4: } { @@_convert_#3_#1: }
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int, rEXP]{\@@_convert_lowercase_alphanum:n}
+% \begin{macro}[aux, rEXP]{\@@_convert_lowercase_alphanum_loop:N}
+%   This function keeps only letters and digits, with upper case letters
+%   converted to lower case.
+%    \begin{macrocode}
+\cs_new:Npn \@@_convert_lowercase_alphanum:n #1
+  {
+    \exp_after:wN \@@_convert_lowercase_alphanum_loop:N
+      \tl_to_str:n {#1} { ? \__prg_break: }
+    \__prg_break_point:
+  }
+\cs_new:Npn \@@_convert_lowercase_alphanum_loop:N #1
+  {
+    \use_none:n #1
+    \if_int_compare:w `#1 < \c_ninety_one
+      \if_int_compare:w `#1 < \c_sixty_five
+        \if_int_compare:w \c_one < 1#1 \exp_stop_f:
+          #1
+        \fi:
+      \else:
+        \@@_output_byte:n { `#1 + \c_thirty_two }
+      \fi:
+    \else:
+      \if_int_compare:w `#1 < \c_one_hundred_twenty_three
+        \if_int_compare:w `#1 < \c_ninety_seven
+        \else:
+          #1
+        \fi:
+      \fi:
+    \fi:
+    \@@_convert_lowercase_alphanum_loop:N
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_load_catcodes:}
+%   Since encoding files may be loaded at arbitrary places in a \TeX{}
+%   document, including within verbatim mode, we set the catcodes of all
+%   characters appearing in any encoding definition file.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_load_catcodes:
+  {
+    \char_set_catcode_escape:N \\
+    \char_set_catcode_group_begin:N \{
+    \char_set_catcode_group_end:N \}
+    \char_set_catcode_math_toggle:N \$
+    \char_set_catcode_alignment:N \&
+    \char_set_catcode_parameter:N \#
+    \char_set_catcode_math_superscript:N \^
+    \char_set_catcode_ignore:N \ %
+    \char_set_catcode_space:N \~
+    \tl_map_function:nN { abcdefghijklmnopqrstuvwxyz_:ABCDEFILNPSTUX }
+      \char_set_catcode_letter:N
+    \tl_map_function:nN { 0123456789"'?*+-.(),`!/<>[];= }
+      \char_set_catcode_other:N
+    \char_set_catcode_comment:N \%
+    \int_set:Nn \tex_endlinechar:D {32}
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Byte unescape and escape}
+%
+% Strings of bytes may need to be stored in auxiliary files in safe
+% \enquote{escaping} formats. Each such escaping is only loaded as
+% needed. By default, on input any non-byte is filtered out, while the
+% output simply consists in letting bytes through.
+%
+% \begin{macro}[int, rEXP]{\@@_filter_bytes:n}
+% \begin{macro}[aux, rEXP]{\@@_filter_bytes_aux:N}
+%   In the case of pdf\TeX{}, every character is a byte.  For
+%   Unicode-aware engines, test the character code; non-bytes cause us
+%   to raise the flag \texttt{str_byte}.  Spaces have already been given
+%   the correct category code when this function is called.
+%    \begin{macrocode}
+\pdftex_if_engine:TF
+  { \cs_new_eq:NN \@@_filter_bytes:n \use:n }
+  {
+    \cs_new:Npn \@@_filter_bytes:n #1
+      {
+        \@@_filter_bytes_aux:N #1
+          { ? \__prg_break: }
+        \__prg_break_point:
+      }
+    \cs_new:Npn \@@_filter_bytes_aux:N #1
+      {
+        \use_none:n #1
+        \if_int_compare:w `#1 < 256 \exp_stop_f:
+          #1
+        \else:
+          \flag_raise:n { str_byte }
+        \fi:
+        \@@_filter_bytes_aux:N
+      }
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_unescape_:}
+% \begin{macro}[int]{\@@_convert_unescape_bytes:}
+%   The simplest unescaping method removes non-bytes from
+%   \cs{g_@@_result_tl}.
+%    \begin{macrocode}
+\pdftex_if_engine:TF
+  { \cs_new_protected_nopar:Npn \@@_convert_unescape_: { } }
+  {
+    \cs_new_protected_nopar:Npn \@@_convert_unescape_:
+      {
+        \flag_clear:n { str_byte }
+        \tl_gset:Nx \g_@@_result_tl
+          { \exp_args:No \@@_filter_bytes:n \g_@@_result_tl }
+        \@@_if_flag_error:nnx { str_byte } { non-byte } { bytes }
+      }
+  }
+\cs_new_eq:NN \@@_convert_unescape_bytes: \@@_convert_unescape_:
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_escape_:}
+% \begin{macro}[int]{\@@_convert_escape_bytes:}
+%   The simplest form of escape leaves the bytes from the previous step
+%   of the conversion unchanged.
+%    \begin{macrocode}
+\cs_new_protected_nopar:Npn \@@_convert_escape_: { }
+\cs_new_eq:NN \@@_convert_escape_bytes: \@@_convert_escape_:
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Native strings}
+%
+% \begin{macro}[int]{\@@_convert_decode_:}
+% \begin{macro}[aux, rEXP]{\@@_decode_native_char:N}
+%   Convert each character to its character code, one at a time.
+%    \begin{macrocode}
+\cs_new_protected_nopar:Npn \@@_convert_decode_:
+  { \@@_convert_gmap:N \@@_decode_native_char:N }
+\cs_new:Npn \@@_decode_native_char:N #1
+  { #1 \s__tl \__int_value:w `#1 \s__tl }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_encode_:}
+%   The conversion from an internal string to native character tokens is
+%   very different in pdf\TeX{} and in other engines. For Unicode-aware
+%   engines, we need the definitions to be read when the null byte has
+%   category code $12$, so we set that inside a group.
+%    \begin{macrocode}
+\group_begin:
+  \char_set_catcode_other:n { 0 }
+  \pdftex_if_engine:TF
+%    \end{macrocode}
+% \begin{macro}[aux, EXP]{\@@_encode_native_char:n}
+%   Since pdf\TeX{} only supports 8-bit characters, and we have a table
+%   of all bytes, the conversion can be done in linear time within an
+%   \texttt{x}-expanding assignment. Look out for character codes larger
+%   than $255$, those characters are replaced by |?|, and raise a flag,
+%   which then triggers a pdf\TeX{}-specific error.
+%    \begin{macrocode}
+    {
+      \cs_new_protected_nopar:Npn \@@_convert_encode_:
+        {
+          \flag_clear:n { str_error }
+          \@@_convert_gmap_internal:N \@@_encode_native_char:n
+          \@@_if_flag_error:nnx { str_error }
+            { pdfTeX-native-overflow } { }
+        }
+      \cs_new:Npn \@@_encode_native_char:n #1
+        {
+          \if_int_compare:w #1 < \c_two_hundred_fifty_six
+            \@@_output_byte:n {#1}
+          \else:
+            \flag_raise:n { str_error }
+            ?
+          \fi:
+        }
+      \__msg_kernel_new:nnnn { str } { pdfTeX-native-overflow }
+        { Character~code~too~large~for~pdfTeX. }
+        {
+          The~pdfTeX~engine~only~supports~8-bit~characters:~
+          valid~character~codes~are~in~the~range~[0,255].~
+          To~manipulate~arbitrary~Unicode,~use~LuaTeX~or~XeTeX.
+        }
+    }
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}[aux]{\@@_encode_native_loop:w}
+% \begin{macro}[aux]{\@@_encode_native_flush:}
+% \begin{macro}[aux, rEXP]{\@@_encode_native_filter:N}
+%   In Unicode-aware engines, since building particular characters
+%   cannot be done expandably in \TeX{}, we cannot hope to get a
+%   linear-time function. However, we get quite close using the
+%   \pkg{l3tl-build} module, which abuses \tn{toks} to reach an almost
+%   linear time. Use the standard lowercase trick to produce an
+%   arbitrary character from the null character, and add that character
+%   to the end of the token list being built. At the end of the loop,
+%   put the token list together with \cs{__tl_build_end:}. Note that we
+%   use an \texttt{x}-expanding assignment because it is slightly
+%   faster. Unicode-aware engines will never incur an overflow because
+%   the internal string is guaranteed to only contain code points in
+%   $[0,\hexnum{10FFFF}]$.
+%    \begin{macrocode}
+    {
+      \cs_new_protected_nopar:Npn \@@_convert_encode_:
+        {
+          \int_zero:N \l__tl_build_offset_int
+          \__tl_gbuild_x:Nw \g_@@_result_tl
+            \exp_after:wN \@@_encode_native_loop:w
+              \g_@@_result_tl \s__tl { \q_stop \__prg_break: } \s__tl
+            \__prg_break_point:
+          \__tl_build_end:
+        }
+      \cs_new_protected:Npn \@@_encode_native_loop:w #1 \s__tl #2 \s__tl
+        {
+          \use_none_delimit_by_q_stop:w #2 \q_stop
+          \tex_lccode:D \l_@@_internal_int \__int_eval:w #2 \__int_eval_end:
+          \tl_to_lowercase:n { \__tl_build_one:n { ^^@ } }
+          \@@_encode_native_loop:w
+        }
+    }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%   End the group to restore the catcode of the null byte.
+%    \begin{macrocode}
+\group_end:
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{8-bit encodings}
+%
+% This section will be entirely rewritten: it is not yet clear in what
+% situations 8-bit encodings are used, hence I don't know what exactly
+% should be optimized. The current approach is reasonably efficient to
+% convert long strings, and it scales well when using many different
+% encodings. An approach based on csnames would have a smaller constant
+% load time for each individual conversion, but has a large hash table
+% cost. Using a range of \tn{count} registers works for decoding, but
+% not for encoding: one possibility there would be to use a binary tree
+% for the mapping of Unicode characters to bytes, stored as a box, one
+% per encoding.
+%
+% Since the section is going to be rewritten, documentation lacks.
+%
+% All the 8-bit encodings which \pkg{l3str} supports rely on the same
+% internal functions.
+%
+% \begin{macro}[int]{\@@_declare_eight_bit_encoding:nnn}
+%   \begin{syntax}
+%     \cs{@@_declare_eight_bit_encoding:nnn} \Arg{name} \Arg{mapping} \Arg{missing}
+%   \end{syntax}
+%   This declares the encoding \meta{name} to map bytes to Unicode
+%   characters according to the \meta{mapping}, and map those bytes
+%   which are not mentionned in the \meta{mapping} either to the
+%   replacement character (if they appear in \meta{missing}), or to
+%   themselves.
+%
+%   All the 8-bit encoding definition file start with
+%   \cs{@@_declare_eight_bit_encoding:nnn} \Arg{encoding name}
+%   \Arg{mapping} \Arg{missing bytes}.  The \meta{mapping} argument is a
+%   token list of pairs \Arg{byte} \Arg{Unicode} expressed in uppercase
+%   hexadecimal notation.  The \meta{missing} argument is a token list
+%   of \Arg{byte}. Every \meta{byte} which does not appear in the
+%   \meta{mapping} nor the \meta{missing} lists maps to the same code
+%   point in Unicode.
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_declare_eight_bit_encoding:nnn #1#2#3
+  {
+    \tl_set:Nn \l_@@_internal_tl {#1}
+    \cs_new_protected_nopar:cpn { @@_convert_decode_#1: }
+      { \@@_convert_decode_eight_bit:n {#1} }
+    \cs_new_protected_nopar:cpn { @@_convert_encode_#1: }
+      { \@@_convert_encode_eight_bit:n {#1} }
+    \tl_const:cn { c_@@_encoding_#1_tl } {#2}
+    \tl_const:cn { c_@@_encoding_#1_missing_tl } {#3}
+  }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_decode_eight_bit:n}
+% \begin{macro}[aux]{\@@_decode_eight_bit_load:nn}
+% \begin{macro}[aux]{\@@_decode_eight_bit_load_missing:n}
+% \begin{macro}[aux, EXP]{\@@_decode_eight_bit_char:N}
+%^^A todo: document
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_convert_decode_eight_bit:n #1
+  {
+    \group_begin:
+      \int_zero:N \l_@@_internal_int
+      \exp_last_unbraced:Nx \@@_decode_eight_bit_load:nn
+        { \tl_use:c { c_@@_encoding_#1_tl } }
+        { \q_stop \__prg_break: } { }
+      \__prg_break_point:
+      \exp_last_unbraced:Nx \@@_decode_eight_bit_load_missing:n
+        { \tl_use:c { c_@@_encoding_#1_missing_tl } }
+        { \q_stop \__prg_break: }
+      \__prg_break_point:
+      \flag_clear:n { str_error }
+      \@@_convert_gmap:N \@@_decode_eight_bit_char:N
+      \@@_if_flag_error:nnx { str_error } { decode-8-bit } {#1}
+    \group_end:
+  }
+\cs_new_protected:Npn \@@_decode_eight_bit_load:nn #1#2
+  {
+    \use_none_delimit_by_q_stop:w #1 \q_stop
+    \tex_dimen:D "#1 = \l_@@_internal_int sp \scan_stop:
+    \tex_skip:D \l_@@_internal_int = "#1 sp \scan_stop:
+    \tex_toks:D \l_@@_internal_int \exp_after:wN { \__int_value:w "#2 }
+    \tex_advance:D \l_@@_internal_int \c_one
+    \@@_decode_eight_bit_load:nn
+  }
+\cs_new_protected:Npn \@@_decode_eight_bit_load_missing:n #1
+  {
+    \use_none_delimit_by_q_stop:w #1 \q_stop
+    \tex_dimen:D "#1 = \l_@@_internal_int sp \scan_stop:
+    \tex_skip:D \l_@@_internal_int = "#1 sp \scan_stop:
+    \tex_toks:D \l_@@_internal_int \exp_after:wN
+      { \int_use:N \c_@@_replacement_char_int }
+    \tex_advance:D \l_@@_internal_int \c_one
+    \@@_decode_eight_bit_load_missing:n
+  }
+\cs_new:Npn \@@_decode_eight_bit_char:N #1
+  {
+    #1 \s__tl
+    \if_int_compare:w \tex_dimen:D `#1 < \l_@@_internal_int
+      \if_int_compare:w \tex_skip:D \tex_dimen:D `#1 = `#1 \exp_stop_f:
+        \tex_the:D \tex_toks:D \tex_dimen:D
+      \fi:
+    \fi:
+    \__int_value:w `#1 \s__tl
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_encode_eight_bit:n}
+% \begin{macro}[aux]{\@@_encode_eight_bit_load:nn}
+% \begin{macro}[aux, rEXP]{\@@_encode_eight_bit_char:n}
+% \begin{macro}[aux, rEXP]{\@@_encode_eight_bit_char_aux:n}
+%^^A todo: document
+%    \begin{macrocode}
+\cs_new_protected:Npn \@@_convert_encode_eight_bit:n #1
+  {
+    \group_begin:
+      \int_zero:N \l_@@_internal_int
+      \exp_last_unbraced:Nx \@@_encode_eight_bit_load:nn
+        { \tl_use:c { c_@@_encoding_#1_tl } }
+        { \q_stop \__prg_break: } { }
+      \__prg_break_point:
+      \flag_clear:n { str_error }
+      \@@_convert_gmap_internal:N \@@_encode_eight_bit_char:n
+      \@@_if_flag_error:nnx { str_error } { encode-8-bit } {#1}
+    \group_end:
+  }
+\cs_new_protected:Npn \@@_encode_eight_bit_load:nn #1#2
+  {
+    \use_none_delimit_by_q_stop:w #1 \q_stop
+    \tex_dimen:D "#2 = \l_@@_internal_int sp \scan_stop:
+    \tex_skip:D \l_@@_internal_int = "#2 sp \scan_stop:
+    \exp_args:NNf \tex_toks:D \l_@@_internal_int
+      { \@@_output_byte:n { "#1 } }
+    \tex_advance:D \l_@@_internal_int \c_one
+    \@@_encode_eight_bit_load:nn
+  }
+\cs_new:Npn \@@_encode_eight_bit_char:n #1
+  {
+    \if_int_compare:w #1 > \c_max_register_int
+      \flag_raise:n { str_error }
+    \else:
+      \if_int_compare:w \tex_dimen:D #1 < \l_@@_internal_int
+        \if_int_compare:w \tex_skip:D \tex_dimen:D #1 = #1 \exp_stop_f:
+          \tex_the:D \tex_toks:D \tex_dimen:D #1 \exp_stop_f:
+          \exp_after:wN \exp_after:wN \exp_after:wN \use_none:nn
+        \fi:
+      \fi:
+      \@@_encode_eight_bit_char_aux:n {#1}
+    \fi:
+  }
+\cs_new:Npn \@@_encode_eight_bit_char_aux:n #1
+  {
+    \if_int_compare:w #1 < \c_two_hundred_fifty_six
+      \@@_output_byte:n {#1}
+    \else:
+      \flag_raise:n { str_error }
+    \fi:
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Messages}
+%
+% General messages, and messages for the encodings and escapings loaded
+% by default (\enquote{native}, and \enquote{bytes}).
+%    \begin{macrocode}
+\__msg_kernel_new:nnn { str } { unknown-esc }
+  { Escaping~scheme~'#1'~(filtered:~'#2')~unknown. }
+\__msg_kernel_new:nnn { str } { unknown-enc }
+  { Encoding~scheme~'#1'~(filtered:~'#2')~unknown. }
+\__msg_kernel_new:nnnn { str } { native-escaping }
+  { The~'native'~encoding~scheme~does~not~support~any~escaping. }
+  {
+    Since~native~strings~do~not~consist~in~bytes,~
+    none~of~the~escaping~methods~make~sense.~
+    The~specified~escaping,~'#1',~will be ignored.
+  }
+\__msg_kernel_new:nnn { str } { file-not-found }
+  { File~'l3str-#1.def'~not~found. }
+%    \end{macrocode}
+%
+% Message used when the \enquote{bytes} unescaping fails because the
+% string given to \cs{str_set_convert:Nnnn} contains a non-byte. This
+% cannot happen for the pdf\TeX{} engine, since that engine only
+% supports 8-bit characters. Messages used for other escapings and
+% encodings are defined in each definition file.
+%    \begin{macrocode}
+\pdftex_if_engine:F
+  {
+    \__msg_kernel_new:nnnn { str } { non-byte }
+      { String~invalid~in~escaping~'#1':~it~may~only~contain~bytes. }
+      {
+        Some~characters~in~the~string~you~asked~to~convert~are~not~
+        8-bit~characters.~Perhaps~the~string~is~a~'native'~Unicode~string?~
+        If~it~is,~try~using\\
+        \\
+        \iow_indent:n
+          {
+            \iow_char:N\\str_set_convert:Nnnn \\
+            \ \ <str~var>~\{~<string>~\}~\{~native~\}~\{~<target~encoding>~\}
+          }
+      }
+  }
+%    \end{macrocode}
+%
+% Those messages are used when converting to and from 8-bit encodings.
+%    \begin{macrocode}
+\__msg_kernel_new:nnnn { str } { decode-8-bit }
+  { Invalid~string~in~encoding~'#1'. }
+  {
+    LaTeX~came~across~a~byte~which~is~not~defined~to~represent~
+    any~character~in~the~encoding~'#1'.
+  }
+\__msg_kernel_new:nnnn { str } { encode-8-bit }
+  { Unicode~string~cannot~be~converted~to~encoding~'#1'. }
+  {
+    The~encoding~'#1'~only~contains~a~subset~of~all~Unicode~characters.~
+    LaTeX~was~asked~to~convert~a~string~to~that~encoding,~but~that~
+    string~contains~a~character~that~'#1'~does~not~support.
+  }
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%</initex|package>
+%    \end{macrocode}
+%
+% \subsection{Escaping definition files}
+%
+% Several of those encodings are defined by the pdf file format.  The
+% following byte storage methods are defined:
+% \begin{itemize}
+%   \item \texttt{bytes} (default), non-bytes are filtered out, and
+%     bytes are left untouched (this is defined by default);
+%   \item \texttt{hex} or \texttt{hexadecimal}, as per the pdf\TeX{}
+%     primitive \tn{pdfescapehex}
+%   \item \texttt{name}, as per the pdf\TeX{} primitive
+%     \tn{pdfescapename}
+%   \item \texttt{string}, as per the pdf\TeX{} primitive
+%     \tn{pdfescapestring}
+%   \item \texttt{url}, as per the percent encoding of urls.
+% \end{itemize}
+%
+% \subsubsection{Unescape methods}
+%
+% \begin{macro}[int]{\@@_convert_unescape_hex:}
+% \begin{macro}[aux, rEXP]{\@@_unescape_hex_auxi:N}
+% \begin{macro}[aux, rEXP]{\@@_unescape_hex_auxii:N}
+%   Take chars two by two, and interpret each pair as the hexadecimal
+%   code for a byte. Anything else than hexadecimal digits is ignored,
+%   raising the flag.  A string which contains an odd number of
+%   hexadecimal digits gets |0| appended to it: this is equivalent to
+%   appending a |0| in all cases, and dropping it if it is alone.
+%    \begin{macrocode}
+%<*hex>
+\cs_new_protected_nopar:Npn \@@_convert_unescape_hex:
+  {
+    \group_begin:
+      \flag_clear:n { str_error }
+      \int_set:Nn \tex_escapechar:D { 92 }
+      \tl_gset:Nx \g_@@_result_tl
+        {
+          \@@_output_byte:w "
+            \exp_last_unbraced:Nf \@@_unescape_hex_auxi:N
+              { \tl_to_str:N \g_@@_result_tl }
+            0 { ? 0 - \c_one \__prg_break: }
+            \__prg_break_point:
+          \@@_output_end:
+        }
+      \@@_if_flag_error:nnx { str_error } { unescape-hex } { }
+    \group_end:
+  }
+\cs_new:Npn \@@_unescape_hex_auxi:N #1
+  {
+    \use_none:n #1
+    \@@_hexadecimal_use:NTF #1
+      { \@@_unescape_hex_auxii:N }
+      {
+        \flag_raise:n { str_error }
+        \@@_unescape_hex_auxi:N
+      }
+  }
+\cs_new:Npn \@@_unescape_hex_auxii:N #1
+  {
+    \use_none:n #1
+    \@@_hexadecimal_use:NTF #1
+      {
+        \@@_output_end:
+        \@@_output_byte:w " \@@_unescape_hex_auxi:N
+      }
+      {
+        \flag_raise:n { str_error }
+        \@@_unescape_hex_auxii:N
+      }
+  }
+\__msg_kernel_new:nnnn { str } { unescape-hex }
+  { String~invalid~in~escaping~'hex':~only~hexadecimal~digits~allowed. }
+  {
+    Some~characters~in~the~string~you~asked~to~convert~are~not~
+    hexadecimal~digits~(0-9,~A-F,~a-f)~nor~spaces.
+  }
+%</hex>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_unescape_name:}
+% \begin{macro}[aux, rEXP]{\@@_unescape_name_loop:wNN}
+% \begin{macro}[int]{\@@_convert_unescape_url:}
+% \begin{macro}[aux, rEXP]{\@@_unescape_url_loop:wNN}
+%   The \cs{@@_convert_unescape_name:} function replaces each
+%   occurrence of |#| followed by two hexadecimal digits in
+%   \cs{g_@@_result_tl} by the corresponding byte.  The \texttt{url}
+%   function is identical, with escape character |%| instead of |#|.
+%   Thus we define the two together. The arguments of \cs{@@_tmp:w} are
+%   the character code of |#| or |%| in hexadecimal, the name of the
+%   main function to define, and the name of the auxiliary which
+%   performs the loop.
+%
+%   The looping auxiliary |#3| finds the next escape character, reads
+%   the following two characters, and tests them. The test
+%   \cs{@@_hexadecimal_use:NTF} leaves the upper-case digit in the
+%   input stream, hence we surround the test with
+%   \cs{@@_output_byte:w}~|"| and \cs{@@_output_end:}.  If both
+%   characters are hexadecimal digits, they should be removed before
+%   looping: this is done by \cs{use_i:nnn}.  If one of the characters
+%   is not a hexadecimal digit, then feed |"#1| to
+%   \cs{@@_output_byte:w} to produce the escape character, raise the
+%   flag, and call the looping function followed by the two characters
+%   (remove \cs{use_i:nnn}).
+%    \begin{macrocode}
+%<*name|url>
+\cs_set_protected:Npn \@@_tmp:w #1#2#3
+  {
+    \cs_new_protected:cpn { @@_convert_unescape_#2: }
+      {
+        \group_begin:
+          \flag_clear:n { str_byte }
+          \flag_clear:n { str_error }
+          \int_set:Nn \tex_escapechar:D { 92 }
+          \tl_gset:Nx \g_@@_result_tl
+            {
+              \exp_after:wN #3 \g_@@_result_tl
+                #1 ? { ? \__prg_break: }
+              \__prg_break_point:
+            }
+          \@@_if_flag_error:nnx { str_byte } { non-byte } { #2 }
+          \@@_if_flag_error:nnx { str_error } { unescape-#2 } { }
+        \group_end:
+      }
+    \cs_new:Npn #3 ##1#1##2##3
+      {
+        \@@_filter_bytes:n {##1}
+        \use_none:n ##3
+        \@@_output_byte:w "
+          \@@_hexadecimal_use:NTF ##2
+            {
+              \@@_hexadecimal_use:NTF ##3
+                { }
+                {
+                  \flag_raise:n { str_error }
+                  * \c_zero + `#1 \use_i:nn
+                }
+            }
+            {
+              \flag_raise:n { str_error }
+              0 + `#1 \use_i:nn
+            }
+        \@@_output_end:
+        \use_i:nnn #3 ##2##3
+      }
+    \__msg_kernel_new:nnnn { str } { unescape-#2 }
+      { String~invalid~in~escaping~'#2'. }
+      {
+        LaTeX~came~across~the~escape~character~'#1'~not~followed~by~
+        two~hexadecimal~digits.~This~is~invalid~in~the~escaping~'#2'.
+      }
+  }
+%</name|url>
+%<*name>
+\exp_after:wN \@@_tmp:w \c_hash_str { name }
+  \@@_unescape_name_loop:wNN
+%</name>
+%<*url>
+\exp_after:wN \@@_tmp:w \c_percent_str { url }
+  \@@_unescape_url_loop:wNN
+%</url>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_unescape_string:}
+% \begin{macro}[aux, rEXP]{\@@_unescape_string_newlines:wN}
+% \begin{macro}[aux, rEXP]{\@@_unescape_string_loop:wNNN}
+% \begin{macro}[aux, rEXP]{\@@_unescape_string_repeat:NNNNNN}
+%   The \texttt{string} escaping is somewhat similar to the
+%   \texttt{name} and \texttt{url} escapings, with escape character |\|.
+%   The first step is to convert all three line endings, |^^J|, |^^M|,
+%   and |^^M^^J| to the common |^^J|, as per the \textsc{pdf}
+%   specification.  This step cannot raise the flag.
+%
+%   Then the following escape sequences are decoded.
+%   \begin{itemize}\def\makelabel#1{\hss\llap{\ttfamily\string#1}}
+%     \item[\n] Line feed ($10$)
+%     \item[\r] Carriage return ($13$)
+%     \item[\t] Horizontal tab ($9$)
+%     \item[\b] Backspace ($8$)
+%     \item[\f] Form feed ($12$)
+%     \item[\(] Left parenthesis
+%     \item[\)] Right parenthesis
+%     \item[\\] Backslash
+%     \item[\ddd] (backslash followed by $1$ to $3$ octal digits) Byte
+%       \texttt{ddd} (octal), subtracting $256$ in case of overflow.
+%   \end{itemize}
+%   If followed by an end-of-line character, the backslash and the
+%   end-of-line are ignored. If followed by anything else, the backslash
+%   is ignored, raising the error flag.
+%^^A Be paranoid: \tl_to_lowercase:n is unsafe.
+%    \begin{macrocode}
+%<*string>
+\group_begin:
+  \char_set_lccode:nn {`\*} {`\\}
+  \char_set_catcode_other:N \^^J
+  \char_set_catcode_other:N \^^M
+  \tl_to_lowercase:n
+    {
+      \cs_new_protected_nopar:Npn \@@_convert_unescape_string:
+        {
+          \group_begin:
+            \flag_clear:n { str_byte }
+            \flag_clear:n { str_error }
+            \int_set:Nn \tex_escapechar:D { 92 }
+            \tl_gset:Nx \g_@@_result_tl
+              {
+                \exp_after:wN \@@_unescape_string_newlines:wN
+                  \g_@@_result_tl \__prg_break: ^^M ?
+                \__prg_break_point:
+              }
+            \tl_gset:Nx \g_@@_result_tl
+              {
+                \exp_after:wN \@@_unescape_string_loop:wNNN
+                  \g_@@_result_tl * ?? { ? \__prg_break: }
+                \__prg_break_point:
+              }
+            \@@_if_flag_error:nnx { str_byte } { non-byte } { string }
+            \@@_if_flag_error:nnx { str_error } { unescape-string } { }
+          \group_end:
+        }
+      \cs_new:Npn \@@_unescape_string_loop:wNNN #1 *#2#3#4
+    }
+        {
+          \@@_filter_bytes:n {#1}
+          \use_none:n #4
+          \@@_output_byte:w '
+            \@@_octal_use:NTF #2
+              {
+                \@@_octal_use:NTF #3
+                  {
+                    \@@_octal_use:NTF #4
+                      {
+                        \if_int_compare:w #2 > \c_three
+                          - 256
+                        \fi:
+                        \@@_unescape_string_repeat:NNNNNN
+                      }
+                      { \@@_unescape_string_repeat:NNNNNN ? }
+                  }
+                  { \@@_unescape_string_repeat:NNNNNN ?? }
+              }
+              {
+                \str_case_x:nnn {#2}
+                  {
+                    { \c_backslash_str } { 134 }
+                    { ( } { 50 }
+                    { ) } { 51 }
+                    { r } { 15 }
+                    { f } { 14 }
+                    { n } { 12 }
+                    { t } { 11 }
+                    { b } { 10 }
+                    { ^^J } { 0 - \c_one }
+                  }
+                  {
+                    \flag_raise:n { str_error }
+                    0 - \c_one \use_i:nn
+                  }
+              }
+          \@@_output_end:
+          \use_i:nn \@@_unescape_string_loop:wNNN #2#3#4
+        }
+  \cs_new:Npn \@@_unescape_string_repeat:NNNNNN #1#2#3#4#5#6
+    { \@@_output_end: \@@_unescape_string_loop:wNNN }
+  \cs_new:Npn \@@_unescape_string_newlines:wN #1 ^^M #2
+    {
+      #1
+      \if_charcode:w ^^J #2 \else: ^^J \fi:
+      \@@_unescape_string_newlines:wN #2
+    }
+  \__msg_kernel_new:nnnn { str } { unescape-string }
+    { String~invalid~in~escaping~'string'. }
+    {
+      LaTeX~came~across~an~escape~character~'\c_backslash_str'~
+      not~followed~by~any~of:~'n',~'r',~'t',~'b',~'f',~'(',~')',~
+      '\c_backslash_str',~one~to~three~octal~digits,~or~the~end~
+      of~a~line.
+    }
+\group_end:
+%</string>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Escape methods}
+%
+% Currently, none of the escape methods can lead to errors, assuming
+% that their input is made out of bytes.
+%
+% \begin{macro}[int]{\@@_convert_escape_hex:}
+% \begin{macro}[aux, rEXP]{\@@_escape_hex_char:N}
+%   Loop and convert each byte to hexadecimal.
+%    \begin{macrocode}
+%<*hex>
+\cs_new_protected_nopar:Npn \@@_convert_escape_hex:
+  { \@@_convert_gmap:N \@@_escape_hex_char:N }
+\cs_new:Npn \@@_escape_hex_char:N #1
+  { \@@_output_hexadecimal:n { `#1 } }
+%</hex>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_escape_name:}
+% \begin{macro}[aux, rEXP]{\@@_escape_name_char:N}
+% \begin{macro}[aux, rEXP]{\@@_if_escape_name:NTF}
+% \begin{variable}{\c_@@_escape_name_str}
+% \begin{variable}{\c_@@_escape_name_not_str}
+%   For each byte, test whether it should be output as is, or be
+%   \enquote{hash-encoded}.  Roughly, bytes outside the range
+%   $[\hexnum{2A},\hexnum{7E}]$ are hash-encoded. We keep two lists of
+%   exceptions: characters in \cs{c_@@_escape_name_not_str} are not
+%   hash-encoded, and characters in the \cs{c_@@_escape_name_str} are
+%   encoded.
+%    \begin{macrocode}
+%<*name>
+\str_const:Nn \c_@@_escape_name_not_str { ! " $ & ' } %$
+\str_const:Nn \c_@@_escape_name_str { {}/<>[] }
+\cs_new_protected_nopar:Npn \@@_convert_escape_name:
+  { \@@_convert_gmap:N \@@_escape_name_char:N }
+\cs_new:Npn \@@_escape_name_char:N #1
+  {
+    \@@_if_escape_name:NTF #1 {#1}
+      { \c_hash_str \@@_output_hexadecimal:n {`#1} }
+  }
+\prg_new_conditional:Npnn \@@_if_escape_name:N #1 { TF }
+  {
+    \if_int_compare:w `#1 < "2A \exp_stop_f:
+      \@@_if_contains_char:NNTF \c_@@_escape_name_not_str #1
+        \prg_return_true: \prg_return_false:
+    \else:
+      \if_int_compare:w `#1 > "7E \exp_stop_f:
+        \prg_return_false:
+      \else:
+        \@@_if_contains_char:NNTF \c_@@_escape_name_str #1
+          \prg_return_false: \prg_return_true:
+      \fi:
+    \fi:
+  }
+%</name>
+%    \end{macrocode}
+% \end{variable}
+% \end{variable}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_escape_string:}
+% \begin{macro}[aux, rEXP]{\@@_escape_string_char:N}
+% \begin{macro}[aux, rEXP]{\@@_if_escape_string:NTF}
+% \begin{variable}{\c_@@_escape_string_str}
+%   Any character below (and including) space, and any character above
+%   (and including) \texttt{del}, are converted to octal.  One backslash
+%   is added before each parenthesis and backslash.
+%    \begin{macrocode}
+%<*string>
+\str_const:Nx \c_@@_escape_string_str
+  { \c_backslash_str ( ) }
+\cs_new_protected_nopar:Npn \@@_convert_escape_string:
+  { \@@_convert_gmap:N \@@_escape_string_char:N }
+\cs_new:Npn \@@_escape_string_char:N #1
+  {
+    \@@_if_escape_string:NTF #1
+      {
+        \@@_if_contains_char:NNT
+          \c_@@_escape_string_str #1
+          { \c_backslash_str }
+        #1
+      }
+      {
+        \c_backslash_str
+        \int_div_truncate:nn {`#1} {64}
+        \int_mod:nn { \int_div_truncate:nn {`#1} \c_eight } \c_eight
+        \int_mod:nn {`#1} \c_eight
+      }
+  }
+\prg_new_conditional:Npnn \@@_if_escape_string:N #1 { TF }
+  {
+    \if_int_compare:w `#1 < "21 \exp_stop_f:
+      \prg_return_false:
+    \else:
+      \if_int_compare:w `#1 > "7E \exp_stop_f:
+        \prg_return_false:
+      \else:
+        \prg_return_true:
+      \fi:
+    \fi:
+  }
+%</string>
+%    \end{macrocode}
+% \end{variable}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[int]{\@@_convert_escape_url:}
+% \begin{macro}[aux, rEXP]{\@@_escape_url_char:N}
+% \begin{macro}[aux, rEXP]{\@@_if_escape_url:NTF}
+%   This function is similar to \cs{@@_convert_escape_name:}, escaping
+%   different characters.
+%    \begin{macrocode}
+%<*url>
+\cs_new_protected_nopar:Npn \@@_convert_escape_url:
+  { \@@_convert_gmap:N \@@_escape_url_char:N }
+\cs_new:Npn \@@_escape_url_char:N #1
+  {
+    \@@_if_escape_url:NTF #1 {#1}
+      { \c_percent_str \@@_output_hexadecimal:n { `#1 } }
+  }
+\prg_new_conditional:Npnn \@@_if_escape_url:N #1 { TF }
+  {
+    \if_int_compare:w `#1 < "41 \exp_stop_f:
+      \@@_if_contains_char:nNTF { "-.<> } #1
+        \prg_return_true: \prg_return_false:
+    \else:
+      \if_int_compare:w `#1 > "7E \exp_stop_f:
+        \prg_return_false:
+      \else:
+        \@@_if_contains_char:nNTF { [ ] } #1
+          \prg_return_false: \prg_return_true:
+      \fi:
+    \fi:
+  }
+%</url>
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Encoding definition files}
+%
+% The \texttt{native} encoding is automatically defined. Other encodings
+% are loaded as needed. The following encodings are supported:
+% \begin{itemize}
+%   \item \textsc{utf-8};
+%   \item \textsc{utf-16}, big-, little-endian, or with byte order mark;
+%   \item \textsc{utf-32}, big-, little-endian, or with byte order mark;
+%   \item the \textsc{iso 8859} code pages, numbered from $1$ to $16$,
+%     skipping the inexistent \textsc{iso 8859-12}.
+% \end{itemize}
+%
+% \subsubsection{\textsc{utf-8} support}
+%
+%    \begin{macrocode}
+%<*utf8>
+%    \end{macrocode}
+%
+% \begin{macro}[int]{\@@_convert_encode_utf8:}
+% \begin{macro}[aux, rEXP]{\@@_encode_utf_viii_char:n}
+% \begin{macro}[aux, rEXP]{\@@_encode_utf_viii_loop:wwnnw}
+%   Loop through the internal string, and convert each character to its
+%   \textsc{utf-8} representation. The representation is built from the
+%   right-most (least significant) byte to the left-most (most
+%   significant) byte. Continuation bytes are in the range $[128,191]$,
+%   taking $64$ different values, hence we roughly want to express the
+%   character code in base $64$, shifting the first digit in the
+%   representation by some number depending on how many continuation
+%   bytes there are. In the range $[0,127]$, output the corresponding
+%   byte directly. In the range $[128,2047]$, output the remainder
+%   modulo $64$, plus $128$ as a continuation byte, then output the
+%   quotient (which is in the range $[0,31]$), shifted by $192$. In the
+%   next range, $[2048,65535]$, split the character code into residue
+%   and quotient modulo $64$, output the residue as a first continuation
+%   byte, then repeat; this leaves us with a quotient in the range
+%   $[0,15]$, which we output shifted by $224$. The last range,
+%   $[65536,1114111]$, follows the same pattern: once we realize that
+%   dividing twice by $64$ leaves us with a number larger than $15$, we
+%   repeat, producing a last continuation byte, and offset the quotient
+%   by $240$ for the leading byte.
+%
+%   How is that implemented? \cs{@@_encode_utf_vii_loop:wwnnw} takes
+%   successive quotients as its first argument, the quotient from the
+%   previous step as its second argument (except in step~$1$), the bound
+%   for quotients that trigger one more step or not, and finally the
+%   offset used if this step should produce the leading byte. Leading
+%   bytes can be in the ranges $[0,127]$, $[192,223]$, $[224,239]$, and
+%   $[240,247]$ (really, that last limit should be $244$ because Unicode
+%   stops at the code point $1114111$). At each step, if the quotient
+%   |#1| is less than the limit |#3| for that range, output the leading
+%   byte (|#1| shifted by |#4|) and stop. Otherwise, we need one more
+%   step: use the quotient of |#1| by $64$, and |#1| as arguments for
+%   the looping auxiliary, and output the continuation byte
+%   corresponding to the remainder $|#2|-64|#1|+128$. The bizarre
+%   construction |\c_minus_one + \c_zero *| removes the spurious initial
+%   continuation byte (better methods welcome).
+%    \begin{macrocode}
+\cs_new_protected_nopar:cpn { @@_convert_encode_utf8: }
+  { \@@_convert_gmap_internal:N \@@_encode_utf_viii_char:n }
+\cs_new:Npn \@@_encode_utf_viii_char:n #1
+  {
+    \@@_encode_utf_viii_loop:wwnnw #1 ; \c_minus_one + \c_zero * ;
+      { 128 } { \c_zero }
+      {  32 } {     192 }
+      {  16 } {     224 }
+      {   8 } {     240 }
+    \q_stop
+  }
+\cs_new:Npn \@@_encode_utf_viii_loop:wwnnw #1; #2; #3#4 #5 \q_stop
+  {
+    \if_int_compare:w #1 < #3 \exp_stop_f:
+      \@@_output_byte:n { #1 + #4 }
+      \exp_after:wN \use_none_delimit_by_q_stop:w
+    \fi:
+    \exp_after:wN \@@_encode_utf_viii_loop:wwnnw
+      \__int_value:w \int_div_truncate:nn {#1} {64} ; #1 ;
+      #5 \q_stop
+    \@@_output_byte:n { #2 - 64 * ( #1 - \c_two ) }
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{variable}
+%   {
+%     \l_@@_missing_flag  ,
+%     \l_@@_extra_flag    ,
+%     \l_@@_overlong_flag ,
+%     \l_@@_overflow_flag ,
+%   }
+%   When decoding a string that is purportedly in the \textsc{utf-8}
+%   encoding, four different errors can occur, signalled by a specific
+%   flag for each (we define those flags using \cs{flag_clear_new:n}
+%   rather than \cs{flag_new:n}, because they are shared with other
+%   encoding definition files).
+%   \begin{itemize}
+%     \item \enquote{Missing continuation byte}: a leading byte is not
+%       followed by the right number of continuation bytes.
+%     \item \enquote{Extra continuation byte}: a continuation byte
+%       appears where it was not expected, \emph{i.e.}, not after an
+%       appropriate leading byte.
+%     \item \enquote{Overlong}: a Unicode character is expressed using
+%       more bytes than necessary, for instance, \hexnum{C0}\hexnum{80}
+%       for the code point $0$, instead of a single null byte.
+%     \item \enquote{Overflow}: this occurs when decoding produces
+%       Unicode code points greater than $1114111$.
+%   \end{itemize}
+%   We only raise one \LaTeX3 error message, combining all the errors
+%   which occurred. In the short message, the leading comma must be
+%   removed to get a grammatically correct sentence. In the long text,
+%   first remind the user what a correct \textsc{utf-8} string should
+%   look like, then add error-specific information.
+%    \begin{macrocode}
+\flag_clear_new:n { str_missing }
+\flag_clear_new:n { str_extra }
+\flag_clear_new:n { str_overlong }
+\flag_clear_new:n { str_overflow }
+\__msg_kernel_new:nnnn { str } { utf8-decode }
+  {
+    Invalid~UTF-8~string: \exp_last_unbraced:Nf \use_none:n
+    \@@_if_flag_times:nT { str_missing }  { ,~missing~continuation~byte }
+    \@@_if_flag_times:nT { str_extra }    { ,~extra~continuation~byte }
+    \@@_if_flag_times:nT { str_overlong } { ,~overlong~form }
+    \@@_if_flag_times:nT { str_overflow } { ,~code~point~too~large }
+    .
+  }
+  {
+    In~the~UTF-8~encoding,~each~Unicode~character~consists~in~
+    1~to~4~bytes,~with~the~following~bit~pattern: \\
+    \iow_indent:n
+      {
+        Code~point~\ \ \ \ <~128:~0xxxxxxx \\
+        Code~point~\ \ \  <~2048:~110xxxxx~10xxxxxx \\
+        Code~point~\ \   <~65536:~1110xxxx~10xxxxxx~10xxxxxx \\
+        Code~point~    <~1114112:~11110xxx~10xxxxxx~10xxxxxx~10xxxxxx \\
+      }
+    Bytes~of~the~form~10xxxxxx~are~called~continuation~bytes.
+    \flag_if_raised:nT { str_missing }
+      {
+        \\\\
+        A~leading~byte~(in~the~range~[192,255])~was~not~followed~by~
+        the~appropriate~number~of~continuation~bytes.
+      }
+    \flag_if_raised:nT { str_extra }
+      {
+        \\\\
+        LaTeX~came~across~a~continuation~byte~when~it~was~not~expected.
+      }
+    \flag_if_raised:nT { str_overlong }
+      {
+        \\\\
+        Every~Unicode~code~point~must~be~expressed~in~the~shortest~
+        possible~form.~For~instance,~'0xC0'~'0x83'~is~not~a~valid~
+        representation~for~the~code~point~3.
+      }
+    \flag_if_raised:nT { str_overflow }
+      {
+        \\\\
+        Unicode~limits~code~points~to~the~range~[0,1114111].
+      }
+  }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}[int]{\@@_convert_decode_utf8:}
+% \begin{macro}[aux, rEXP]
+%   {
+%     \@@_decode_utf_viii_start:N,
+%     \@@_decode_utf_viii_continuation:wwN,
+%     \@@_decode_utf_viii_aux:wNnnwN
+%   }
+% \begin{macro}[aux, rEXP]
+%   {\@@_decode_utf_viii_overflow:w, \@@_decode_utf_viii_end:}
+%   Decoding is significantly harder than encoding. As before, lower
+%   some flags, which are tested at the end (in bulk, to trigger at most
+%   one \LaTeX3 error, as explained above). We expect successive
+%   multi-byte sequences of the form \meta{start byte}
+%   \meta{continuation bytes}. The \texttt{_start} auxiliary tests the
+%   first byte:
+%   \begin{itemize}
+%     \item $[0,\hexnum{7F}]$: the byte stands alone, and is converted
+%       to its own character code;
+%     \item $[\hexnum{80}, \hexnum{BF}]$: unexpected continuation byte,
+%       raise the appropriate flag, and convert that byte to the
+%       replacement character \hexnum{FFFD};
+%     \item $[\hexnum{C0}, \hexnum{FF}]$: this byte should be followed
+%       by some continuation byte(s).
+%   \end{itemize}
+%   In the first two cases, \cs{use_none_delimit_by_q_stop:w} removes
+%   data that only the third case requires, namely the limits of ranges
+%   of Unicode characters which can be expressed with $1$, $2$, $3$, or
+%   $4$ bytes.
+%
+%   We can now concentrate on the multi-byte case and the
+%   \texttt{_continuation} auxiliary. We expect |#3| to be in the range
+%   $[\hexnum{80}, \hexnum{BF}]$. The test for this goes as follows: if
+%   the character code is less than \hexnum{80}, we compare it to
+%   $-\hexnum{C0}$, yielding \texttt{false}; otherwise to \hexnum{C0},
+%   yielding \texttt{true} in the range $[\hexnum{80}, \hexnum{BF}]$ and
+%   \texttt{false} otherwise. If we find that the byte is not a
+%   continuation range, stop the current slew of bytes, output the
+%   replacement character, and continue parsing with the \texttt{_start}
+%   auxiliary, starting at the byte we just tested. Once we know that
+%   the byte is a continuation byte, leave it behind us in the input
+%   stream, compute what code point the bytes read so far would produce,
+%   and feed that number to the \texttt{_aux} function.
+%
+%   The \texttt{_aux} function tests whether we should look for more
+%   continuation bytes or not. If the number it receives as |#1| is less
+%   than the maximum |#4| for the current range, then we are done: check
+%   for an overlong representation by comparing |#1| with the maximum
+%   |#3| for the previous range. Otherwise, we call the
+%   \texttt{_continuation} auxiliary again, after shifting the
+%   \enquote{current code point} by |#4| (maximum from the range we just
+%   checkedd).
+%
+%   Two additional tests are needed: if we reach the end of the list of
+%   range maxima and we are still not done, then we are faced with an
+%   overflow. Clean up, and again insert the code point \hexnum{FFFD}
+%   for the replacement character. Also, every time we read a byte, we
+%   need to check whether we reached the end of the string. In a correct
+%   \textsc{utf-8} string, this happens automatically when the
+%   \texttt{_start} auxiliary leaves its first argument in the input
+%   stream: the end-marker begins with \cs{__prg_break:}, which ends
+%   the loop. On the other hand, if the end is reached when looking for
+%   a continuation byte, the \cs{use_none:n} |#3| construction removes
+%   the first token from the end-marker, and leaves the \texttt{_end}
+%   auxiliary, which raises the appropriate error flag before ending the
+%   mapping.
+%    \begin{macrocode}
+\cs_new_protected_nopar:cpn { @@_convert_decode_utf8: }
+  {
+    \flag_clear:n { str_error }
+    \flag_clear:n { str_missing }
+    \flag_clear:n { str_extra }
+    \flag_clear:n { str_overlong }
+    \flag_clear:n { str_overflow }
+    \tl_gset:Nx \g_@@_result_tl
+      {
+        \exp_after:wN \@@_decode_utf_viii_start:N \g_@@_result_tl
+          { \__prg_break: \@@_decode_utf_viii_end: }
+        \__prg_break_point:
+      }
+    \@@_if_flag_error:nnx { str_error } { utf8-decode } { }
+  }
+\cs_new:Npn \@@_decode_utf_viii_start:N #1
+  {
+    #1
+    \if_int_compare:w `#1 < "C0 \exp_stop_f:
+      \s__tl
+      \if_int_compare:w `#1 < "80 \exp_stop_f:
+        \__int_value:w `#1
+      \else:
+        \flag_raise:n { str_extra }
+        \flag_raise:n { str_error }
+        \int_use:N \c_@@_replacement_char_int
+      \fi:
+    \else:
+      \exp_after:wN \@@_decode_utf_viii_continuation:wwN
+      \int_use:N \__int_eval:w `#1 - "C0 \exp_after:wN \__int_eval_end:
+    \fi:
+    \s__tl
+    \use_none_delimit_by_q_stop:w {"80} {"800} {"10000} {"110000} \q_stop
+    \@@_decode_utf_viii_start:N
+  }
+\cs_new:Npn \@@_decode_utf_viii_continuation:wwN
+    #1 \s__tl #2 \@@_decode_utf_viii_start:N #3
+  {
+    \use_none:n #3
+    \if_int_compare:w `#3 <
+          \if_int_compare:w `#3 < "80 \exp_stop_f: - \fi:
+          "C0 \exp_stop_f:
+      #3
+      \exp_after:wN \@@_decode_utf_viii_aux:wNnnwN
+      \int_use:N \__int_eval:w
+        #1 * "40 + `#3 - "80
+      \exp_after:wN \__int_eval_end:
+    \else:
+      \s__tl
+      \flag_raise:n { str_missing }
+      \flag_raise:n { str_error }
+      \int_use:N \c_@@_replacement_char_int
+    \fi:
+    \s__tl
+    #2
+    \@@_decode_utf_viii_start:N #3
+  }
+\cs_new:Npn \@@_decode_utf_viii_aux:wNnnwN
+    #1 \s__tl #2#3#4 #5 \@@_decode_utf_viii_start:N #6
+  {
+    \if_int_compare:w #1 < #4 \exp_stop_f:
+      \s__tl
+      \if_int_compare:w #1 < #3 \exp_stop_f:
+        \flag_raise:n { str_overlong }
+        \flag_raise:n { str_error }
+        \int_use:N \c_@@_replacement_char_int
+      \else:
+        #1
+      \fi:
+    \else:
+      \if_meaning:w \q_stop #5
+        \@@_decode_utf_viii_overflow:w #1
+      \fi:
+      \exp_after:wN \@@_decode_utf_viii_continuation:wwN
+      \int_use:N \__int_eval:w #1 - #4 \exp_after:wN \__int_eval_end:
+    \fi:
+    \s__tl
+    #2 {#4} #5
+    \@@_decode_utf_viii_start:N
+  }
+\cs_new:Npn \@@_decode_utf_viii_overflow:w #1 \fi: #2 \fi:
+  {
+    \fi: \fi:
+    \flag_raise:n { str_overflow }
+    \flag_raise:n { str_error }
+    \int_use:N \c_@@_replacement_char_int
+  }
+\cs_new_nopar:Npn \@@_decode_utf_viii_end:
+  {
+    \s__tl
+    \flag_raise:n { str_missing }
+    \flag_raise:n { str_error }
+    \int_use:N \c_@@_replacement_char_int \s__tl
+    \__prg_break:
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+%    \begin{macrocode}
+%</utf8>
+%    \end{macrocode}
+%
+% \subsubsection{\textsc{utf-16} support}
+%
+% The definitions are done in a category code regime where the bytes
+% $254$ and $255$ used by the byte order mark have catcode~$12$.
+%    \begin{macrocode}
+%<*utf16>
+\group_begin:
+  \char_set_catcode_other:N \^^fe
+  \char_set_catcode_other:N \^^ff
+%    \end{macrocode}
+%
+% \begin{macro}[int]
+%   {
+%     \@@_convert_encode_utf16:   ,
+%     \@@_convert_encode_utf16be: ,
+%     \@@_convert_encode_utf16le: ,
+%   }
+% \begin{macro}[aux, rEXP]
+%   {
+%     \@@_encode_utf_xvi_aux:N  ,
+%     \@@_encode_utf_xvi_char:n ,
+%   }
+%   When the endianness is not specified, it is big-endian by default,
+%   and we add a byte-order mark.  Convert characters one by one in a
+%   loop, with different behaviours depending on the character code.
+%   \begin{itemize}
+%     \item $[0, \hexnum{D7FF}]$: converted to two bytes;
+%     \item $[\hexnum{D800}, \hexnum{DFFF}]$ are used as surrogates:
+%       they cannot be converted and are replaced by the replacement
+%       character;
+%     \item $[\hexnum{E000}, \hexnum{FFFF}]$: converted to two bytes;
+%     \item $[\hexnum{10000}, \hexnum{10FFFF}]$: converted to a pair of
+%       surrogates, each two bytes. The magic \hexnum{D7C0} is
+%       $\hexnum{D800}-\hexnum{10000}/\hexnum{400}$.
+%   \end{itemize}
+%   For the duration of this operation, \cs{@@_tmp:w} is defined as a
+%   function to convert a number in the range $[0, \hexnum{FFFF}]$ to a
+%   pair of bytes (either big endian or little endian), by feeding the
+%   quotient of the division of |#1| by \hexnum{100}, followed by |#1|
+%   to \cs{@@_encode_utf_xvi_be:nn} or its \texttt{le} analog: those
+%   compute the remainder, and output two bytes for the quotient and
+%   remainder.
+%    \begin{macrocode}
+  \cs_new_protected_nopar:cpn { @@_convert_encode_utf16: }
+    {
+      \@@_encode_utf_xvi_aux:N \@@_output_byte_pair_be:n
+      \tl_gput_left:Nx \g_@@_result_tl { ^^fe ^^ff }
+    }
+  \cs_new_protected_nopar:cpn { @@_convert_encode_utf16be: }
+    { \@@_encode_utf_xvi_aux:N \@@_output_byte_pair_be:n }
+  \cs_new_protected_nopar:cpn { @@_convert_encode_utf16le: }
+    { \@@_encode_utf_xvi_aux:N \@@_output_byte_pair_le:n }
+  \cs_new_protected:Npn \@@_encode_utf_xvi_aux:N #1
+    {
+      \flag_clear:n { str_error }
+      \cs_set_eq:NN \@@_tmp:w #1
+      \@@_convert_gmap_internal:N \@@_encode_utf_xvi_char:n
+      \@@_if_flag_error:nnx { str_error } { utf16-encode } { }
+    }
+  \cs_new:Npn \@@_encode_utf_xvi_char:n #1
+    {
+      \if_int_compare:w #1 < "D800 \exp_stop_f:
+        \@@_tmp:w {#1}
+      \else:
+        \if_int_compare:w #1 < "10000 \exp_stop_f:
+          \if_int_compare:w #1 < "E000 \exp_stop_f:
+            \flag_raise:n { str_error }
+            \@@_tmp:w { \c_@@_replacement_char_int }
+          \else:
+            \@@_tmp:w {#1}
+          \fi:
+        \else:
+          \exp_args:Nf \@@_tmp:w { \int_div_truncate:nn {#1} {"400} + "D7C0 }
+          \exp_args:Nf \@@_tmp:w { \int_mod:nn {#1} {"400} + "DC00 }
+        \fi:
+      \fi:
+    }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{variable}
+%   {
+%     \l_@@_missing_flag ,
+%     \l_@@_extra_flag   ,
+%     \l_@@_end_flag     ,
+%   }
+%   When encoding a Unicode string to \textsc{utf-16}, only one error
+%   can occur: code points in the range $[\hexnum{D800},
+%   \hexnum{DFFF}]$, corresponding to surrogates, cannot be encoded. We
+%   use the all-purpose flag \texttt{@@_error} to signal that error.
+%
+%   When decoding a Unicode string which is purportedly in
+%   \textsc{utf-16}, three errors can occur: a missing trail surrogate,
+%   an unexpected trail surrogate, and a string containing an odd number
+%   of bytes.
+%    \begin{macrocode}
+  \flag_clear_new:n { str_missing }
+  \flag_clear_new:n { str_extra }
+  \flag_clear_new:n { str_end }
+  \__msg_kernel_new:nnnn { str } { utf16-encode }
+    { Unicode~string~cannot~be~expressed~in~UTF-16:~surrogate. }
+    {
+      Surrogate~code~points~(in~the~range~[U+D800,~U+DFFF])~
+      can~be~expressed~in~the~UTF-8~and~UTF-32~encodings,~
+      but~not~in~the~UTF-16~encoding.
+    }
+  \__msg_kernel_new:nnnn { str } { utf16-decode }
+    {
+      Invalid~UTF-16~string: \exp_last_unbraced:Nf \use_none:n
+      \@@_if_flag_times:nT { str_missing }  { ,~missing~trail~surrogate }
+      \@@_if_flag_times:nT { str_extra }    { ,~extra~trail~surrogate }
+      \@@_if_flag_times:nT { str_end }      { ,~odd~number~of~bytes }
+      .
+    }
+    {
+      In~the~UTF-16~encoding,~each~Unicode~character~is~encoded~as~
+      2~or~4~bytes: \\
+      \iow_indent:n
+        {
+          Code~point~in~[U+0000,~U+D7FF]:~two~bytes \\
+          Code~point~in~[U+D800,~U+DFFF]:~illegal \\
+          Code~point~in~[U+E000,~U+FFFF]:~two~bytes \\
+          Code~point~in~[U+10000,~U+10FFFF]:~
+            a~lead~surrogate~and~a~trail~surrogate \\
+        }
+      Lead~surrogates~are~pairs~of~bytes~in~the~range~[0xD800,~0xDBFF],~
+      and~trail~surrogates~are~in~the~range~[0xDC00,~0xDFFF].
+      \flag_if_raised:nT { str_missing }
+        {
+          \\\\
+          A~lead~surrogate~was~not~followed~by~a~trail~surrogate.
+        }
+      \flag_if_raised:nT { str_extra }
+        {
+          \\\\
+          LaTeX~came~across~a~trail~surrogate~when~it~was~not~expected.
+        }
+      \flag_if_raised:nT { str_end }
+        {
+          \\\\
+          The~string~contained~an~odd~number~of~bytes.~This~is~invalid:~
+          the~basic~code~unit~for~UTF-16~is~16~bits~(2~bytes).
+        }
+    }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}[int]
+%   {
+%     \@@_convert_decode_utf16:   ,
+%     \@@_convert_decode_utf16be: ,
+%     \@@_convert_decode_utf16le: ,
+%   }
+% \begin{macro}[aux]{\@@_decode_utf_xvi_bom:NN, \@@_decode_utf_xvi:Nw}
+%   As for \textsc{utf-8}, decoding \textsc{utf-16} is harder than
+%   encoding it. If the endianness is unknown, check the first two
+%   bytes: if those are \hexnum{FE} and \hexnum{FF} in either order,
+%   remove them and use the corresponding endianness, otherwise assume
+%   big-endianness. The three endianness cases are based on a common
+%   auxiliary whose first argument is $1$ for big-endian and $2$ for
+%   little-endian, and whose second argument, delimited by the scan mark
+%   \cs{s__stop}, is expanded once (the string may be long; passing
+%   \cs{g_@@_result_tl} as an argument before expansion is cheaper).
+%
+%   The \cs{@@_decode_utf_xvi:Nw} function defines \cs{@@_tmp:w} to
+%   take two arguments and return the character code of the first one if
+%   the string is big-endian, and the second one if the string is
+%   little-endian, then loops over the string using
+%   \cs{@@_decode_utf_xvi_pair:NN} described below.
+%    \begin{macrocode}
+  \cs_new_protected_nopar:cpn { @@_convert_decode_utf16be: }
+    { \@@_decode_utf_xvi:Nw 1 \g_@@_result_tl \s__stop }
+  \cs_new_protected_nopar:cpn { @@_convert_decode_utf16le: }
+    { \@@_decode_utf_xvi:Nw 2 \g_@@_result_tl \s__stop }
+  \cs_new_protected_nopar:cpn { @@_convert_decode_utf16: }
+    {
+      \exp_after:wN \@@_decode_utf_xvi_bom:NN
+        \g_@@_result_tl \s__stop \s__stop \s__stop
+    }
+  \cs_new_protected:Npn \@@_decode_utf_xvi_bom:NN #1#2
+    {
+      \str_if_eq_x:nnTF { #1#2 } { ^^ff ^^fe }
+        { \@@_decode_utf_xvi:Nw 2 }
+        {
+          \str_if_eq_x:nnTF { #1#2 } { ^^fe ^^ff }
+            { \@@_decode_utf_xvi:Nw 1 }
+            { \@@_decode_utf_xvi:Nw 1 #1#2 }
+        }
+    }
+  \cs_new_protected:Npn \@@_decode_utf_xvi:Nw #1#2 \s__stop
+    {
+      \flag_clear:n { str_error }
+      \flag_clear:n { str_missing }
+      \flag_clear:n { str_extra }
+      \flag_clear:n { str_end }
+      \cs_set:Npn \@@_tmp:w ##1 ##2 { ` ## #1 }
+      \tl_gset:Nx \g_@@_result_tl
+        {
+          \exp_after:wN \@@_decode_utf_xvi_pair:NN
+            #2 \q_nil \q_nil
+          \__prg_break_point:
+        }
+      \@@_if_flag_error:nnx { str_error } { utf16-decode } { }
+    }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}[aux, rEXP]
+%   {
+%     \@@_decode_utf_xvi_pair:NN     ,
+%     \@@_decode_utf_xvi_quad:NNwNN  ,
+%     \@@_decode_utf_xvi_pair_end:Nw ,
+%   }
+% \begin{macro}[aux, rEXP]
+%   {
+%     \@@_decode_utf_xvi_error:nNN ,
+%     \@@_decode_utf_xvi_extra:NNw ,
+%   }
+%   Bytes are read two at a time. At this stage, |\@@_tmp:w #1#2|
+%   expands to the character code of the most significant byte, and we
+%   distinguish cases depending on which range it lies in:
+%   \begin{itemize}
+%     \item $[\hexnum{D8}, \hexnum{DB}]$ signals a lead surrogate, and
+%       the integer expression yields $1$ (\eTeX{} rounds ties away from
+%       zero);
+%     \item $[\hexnum{DC}, \hexnum{DF}]$ signals a trail surrogate,
+%       unexpected here, and the integer expression yields $2$;
+%     \item any other value signals a code point in the Basic
+%       Multilingual Plane, which stands for itself, and the
+%       \cs{if_case:w} construction expands to nothing (cases other than
+%       $1$ or $2$), leaving the relevant material in the input stream,
+%       followed by another call to the \texttt{_pair} auxiliary.
+%   \end{itemize}
+%   The case of a lead surrogate is treated by the \texttt{_quad}
+%   auxiliary, whose arguments |#1|, |#2|, |#4| and |#5| are the four
+%   bytes. We expect the most significant byte of |#4#5| to be in the
+%   range $[\hexnum{DC}, \hexnum{DF}]$ (trail surrogate). The test is
+%   similar to the test used for continuation bytes in the
+%   \textsc{utf-8} decoding functions. In the case where |#4#5| is
+%   indeed a trail surrogate, leave |#1#2#4#5| \cs{s__tl}
+%   \meta{code~point} \cs{s__tl}, and remove the pair |#4#5| before
+%   looping with \cs{@@_decode_utf_xvi_pair:NN}. Otherwise, of course,
+%   complain about the missing surrogate.
+%
+%   The magic number \hexnum{D7F7} is such that
+%   $\hexnum{D7F7}*\hexnum{400} = \hexnum{D800}*\hexnum{400} +
+%   \hexnum{DC00} - \hexnum{10000}$.
+%
+%   Every time we read a pair of bytes, we test for the end-marker
+%   \cs{q_nil}. When reaching the end, we additionally check that the
+%   string had an even length. Also, if the end is reached when
+%   expecting a trail surrogate, we treat that as a missing surrogate.
+%    \begin{macrocode}
+  \cs_new:Npn \@@_decode_utf_xvi_pair:NN #1#2
+    {
+      \if_meaning:w \q_nil #2
+        \@@_decode_utf_xvi_pair_end:Nw #1
+      \fi:
+      \if_case:w
+        \__int_eval:w ( \@@_tmp:w #1#2 - "D6 ) / \c_four \__int_eval_end:
+      \or: \exp_after:wN \@@_decode_utf_xvi_quad:NNwNN
+      \or: \exp_after:wN \@@_decode_utf_xvi_extra:NNw
+      \fi:
+      #1#2 \s__tl
+      \int_eval:n { "100 * \@@_tmp:w #1#2 + \@@_tmp:w #2#1 } \s__tl
+      \@@_decode_utf_xvi_pair:NN
+    }
+  \cs_new:Npn \@@_decode_utf_xvi_quad:NNwNN
+      #1#2 #3 \@@_decode_utf_xvi_pair:NN #4#5
+    {
+      \if_meaning:w \q_nil #5
+        \@@_decode_utf_xvi_error:nNN { missing } #1#2
+        \@@_decode_utf_xvi_pair_end:Nw #4
+      \fi:
+      \if_int_compare:w
+          \if_int_compare:w \@@_tmp:w #4#5 < "DC \exp_stop_f:
+            \c_zero = \c_one
+          \else:
+            \@@_tmp:w #4#5 < "E0 \exp_stop_f:
+          \fi:
+        #1 #2 #4 #5 \s__tl
+        \int_eval:n
+          {
+            ( "100 * \@@_tmp:w #1#2 + \@@_tmp:w #2#1 - "D7F7 ) * "400
+            + "100 * \@@_tmp:w #4#5 + \@@_tmp:w #5#4
+          }
+        \s__tl
+        \exp_after:wN \use_i:nnn
+      \else:
+        \@@_decode_utf_xvi_error:nNN { missing } #1#2
+      \fi:
+      \@@_decode_utf_xvi_pair:NN #4#5
+    }
+  \cs_new:Npn \@@_decode_utf_xvi_pair_end:Nw #1 \fi:
+    {
+      \fi:
+      \if_meaning:w \q_nil #1
+      \else:
+        \@@_decode_utf_xvi_error:nNN { end } #1 \prg_do_nothing:
+      \fi:
+      \__prg_break:
+    }
+  \cs_new:Npn \@@_decode_utf_xvi_extra:NNw #1#2 \s__tl #3 \s__tl
+    { \@@_decode_utf_xvi_error:nNN { extra } #1#2 }
+  \cs_new:Npn \@@_decode_utf_xvi_error:nNN #1#2#3
+    {
+      \flag_raise:n { str_error }
+      \flag_raise:n { str_#1 }
+      #2 #3 \s__tl
+      \int_use:N \c_@@_replacement_char_int \s__tl
+    }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% Restore the original catcodes of bytes $254$ and $255$.
+%    \begin{macrocode}
+\group_end:
+%</utf16>
+%    \end{macrocode}
+%
+% \subsubsection{\textsc{utf-32} support}
+%
+% The definitions are done in a category code regime where the bytes
+% $0$, $254$ and $255$ used by the byte order mark have catcode
+% \enquote{other}.
+%    \begin{macrocode}
+%<*utf32>
+\group_begin:
+  \char_set_catcode_other:N \^^00
+  \char_set_catcode_other:N \^^fe
+  \char_set_catcode_other:N \^^ff
+%    \end{macrocode}
+%
+% \begin{macro}[int]
+%   {
+%     \@@_convert_encode_utf32:   ,
+%     \@@_convert_encode_utf32be: ,
+%     \@@_convert_encode_utf32le: ,
+%   }
+% \begin{macro}[aux, rEXP]
+%   {
+%     \@@_encode_utf_xxxii_be:n      ,
+%     \@@_encode_utf_xxxii_be_aux:nn ,
+%     \@@_encode_utf_xxxii_le:n      ,
+%     \@@_encode_utf_xxxii_le_aux:nn ,
+%   }
+%   Convert each integer in the comma-list \cs{g_@@_result_tl} to a
+%   sequence of four bytes. The functions for big-endian and
+%   little-endian encodings are very similar, but the
+%   \cs{@@_output_byte:n} instructions are reversed.
+%    \begin{macrocode}
+  \cs_new_protected_nopar:cpn { @@_convert_encode_utf32: }
+    {
+      \@@_convert_gmap_internal:N \@@_encode_utf_xxxii_be:n
+      \tl_gput_left:Nx \g_@@_result_tl { ^^00 ^^00 ^^fe ^^ff }
+    }
+  \cs_new_protected_nopar:cpn { @@_convert_encode_utf32be: }
+    { \@@_convert_gmap_internal:N \@@_encode_utf_xxxii_be:n }
+  \cs_new_protected_nopar:cpn { @@_convert_encode_utf32le: }
+    { \@@_convert_gmap_internal:N \@@_encode_utf_xxxii_le:n }
+  \cs_new:Npn \@@_encode_utf_xxxii_be:n #1
+    {
+      \exp_args:Nf \@@_encode_utf_xxxii_be_aux:nn
+        { \int_div_truncate:nn {#1} { "100 } } {#1}
+    }
+  \cs_new:Npn \@@_encode_utf_xxxii_be_aux:nn #1#2
+    {
+      ^^00
+      \@@_output_byte_pair_be:n {#1}
+      \@@_output_byte:n { #2 - #1 * "100 }
+    }
+  \cs_new:Npn \@@_encode_utf_xxxii_le:n #1
+    {
+      \exp_args:Nf \@@_encode_utf_xxxii_le_aux:nn
+        { \int_div_truncate:nn {#1} { "100 } } {#1}
+    }
+  \cs_new:Npn \@@_encode_utf_xxxii_le_aux:nn #1#2
+    {
+      \@@_output_byte:n { #2 - #1 * "100 }
+      \@@_output_byte_pair_le:n {#1}
+      ^^00
+    }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{variable}{str_overflow, str_end}
+%   There can be no error when encoding in \textsc{utf-32}. When
+%   decoding, the string may not have length $4n$, or it may contain
+%   code points larger than \hexnum{10FFFF}. The latter case often
+%   happens if the encoding was in fact not \textsc{utf-32}, because
+%   most arbitrary strings are not valid in \textsc{utf-32}.
+%    \begin{macrocode}
+  \flag_clear_new:n { str_overflow }
+  \flag_clear_new:n { str_end }
+  \__msg_kernel_new:nnnn { str } { utf32-decode }
+    {
+      Invalid~UTF-32~string: \exp_last_unbraced:Nf \use_none:n
+      \@@_if_flag_times:nT { str_overflow } { ,~code~point~too~large }
+      \@@_if_flag_times:nT { str_end }      { ,~truncated~string }
+      .
+    }
+    {
+      In~the~UTF-32~encoding,~every~Unicode~character~
+      (in~the~range~[U+0000,~U+10FFFF])~is~encoded~as~4~bytes.
+      \flag_if_raised:nT { str_overflow }
+        {
+          \\\\
+          LaTeX~came~across~a~code~point~larger~than~1114111,~
+          the~maximum~code~point~defined~by~Unicode.~
+          Perhaps~the~string~was~not~encoded~in~the~UTF-32~encoding?
+        }
+      \flag_if_raised:nT { str_end }
+        {
+          \\\\
+          The~length~of~the~string~is~not~a~multiple~of~4.~
+          Perhaps~the~string~was~truncated?
+        }
+    }
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}[int]
+%   {
+%     \@@_convert_decode_utf32:   ,
+%     \@@_convert_decode_utf32be: ,
+%     \@@_convert_decode_utf32le: ,
+%   }
+% \begin{macro}[aux]
+%   {\@@_decode_utf_xxxii_bom:NNNN, \@@_decode_utf_xxxii:Nw}
+% \begin{macro}[aux, rEXP]
+%   {\@@_decode_utf_xxxii_loop:NNNN, \@@_decode_utf_xxxii_end:w}
+%
+%   The structure is similar to \textsc{utf-16} decoding functions. If
+%   the endianness is not given, test the first $4$ bytes of the string
+%   (possibly \cs{s__stop} if the string is too short) for the presence
+%   of a byte-order mark. If there is a byte-order mark, use that
+%   endianness, and remove the $4$ bytes, otherwise default to
+%   big-endian, and leave the $4$ bytes in place. The
+%   \cs{@@_decode_utf_xxxii:Nw} auxiliary recieves $1$ or $2$ as its
+%   first argument indicating endianness, and the string to convert as
+%   its second argument (expanded or not). It sets \cs{@@_tmp:w} to
+%   expand to the character code of either of its two arguments
+%   depending on endianness, then triggers the \texttt{_loop} auxiliary
+%   inside an \texttt{x}-expanding assignment to \cs{g_@@_result_tl}.
+%
+%   The \texttt{_loop} auxiliary first checks for the end-of-string
+%   marker \cs{s__stop}, calling the \texttt{_end} auxiliary if
+%   appropriate. Otherwise, leave the \meta{4~bytes} \cs{s__tl} behind,
+%   then check that the code point is not overflowing: the leading byte
+%   must be $0$, and the following byte at most $16$.
+%
+%   In the ending code, we check that there remains no byte: there
+%   should be nothing left until the first \cs{s__stop}. Break the map.
+%    \begin{macrocode}
+  \cs_new_protected_nopar:cpn { @@_convert_decode_utf32be: }
+    { \@@_decode_utf_xxxii:Nw 1 \g_@@_result_tl \s__stop }
+  \cs_new_protected_nopar:cpn { @@_convert_decode_utf32le: }
+    { \@@_decode_utf_xxxii:Nw 2 \g_@@_result_tl \s__stop }
+  \cs_new_protected_nopar:cpn { @@_convert_decode_utf32: }
+    {
+      \exp_after:wN \@@_decode_utf_xxxii_bom:NNNN \g_@@_result_tl
+        \s__stop \s__stop \s__stop \s__stop \s__stop
+    }
+  \cs_new_protected:Npn \@@_decode_utf_xxxii_bom:NNNN #1#2#3#4
+    {
+      \str_if_eq_x:nnTF { #1#2#3#4 } { ^^ff ^^fe ^^00 ^^00 }
+        { \@@_decode_utf_xxxii:Nw 2 }
+        {
+          \str_if_eq_x:nnTF { #1#2#3#4 } { ^^00 ^^00 ^^fe ^^ff }
+            { \@@_decode_utf_xxxii:Nw 1 }
+            { \@@_decode_utf_xxxii:Nw 1 #1#2#3#4 }
+        }
+    }
+  \cs_new_protected:Npn \@@_decode_utf_xxxii:Nw #1#2 \s__stop
+    {
+      \flag_clear:n { str_overflow }
+      \flag_clear:n { str_end }
+      \flag_clear:n { str_error }
+      \cs_set:Npn \@@_tmp:w ##1 ##2 { ` ## #1 }
+      \tl_gset:Nx \g_@@_result_tl
+        {
+          \exp_after:wN \@@_decode_utf_xxxii_loop:NNNN
+            #2 \s__stop \s__stop \s__stop \s__stop
+          \__prg_break_point:
+        }
+      \@@_if_flag_error:nnx { str_error } { utf32-decode } { }
+    }
+  \cs_new:Npn \@@_decode_utf_xxxii_loop:NNNN #1#2#3#4
+    {
+      \if_meaning:w \s__stop #4
+        \exp_after:wN \@@_decode_utf_xxxii_end:w
+      \fi:
+      #1#2#3#4 \s__tl
+      \if_int_compare:w \@@_tmp:w #1#4 > \c_zero
+        \flag_raise:n { str_overflow }
+        \flag_raise:n { str_error }
+        \int_use:N \c_@@_replacement_char_int
+      \else:
+        \if_int_compare:w \@@_tmp:w #2#3 > \c_sixteen
+          \flag_raise:n { str_overflow }
+          \flag_raise:n { str_error }
+          \int_use:N \c_@@_replacement_char_int
+        \else:
+          \int_eval:n
+            { \@@_tmp:w #2#3*"10000 + \@@_tmp:w #3#2*"100 + \@@_tmp:w #4#1 }
+        \fi:
+      \fi:
+      \s__tl
+      \@@_decode_utf_xxxii_loop:NNNN
+    }
+  \cs_new:Npn \@@_decode_utf_xxxii_end:w #1 \s__stop
+    {
+      \tl_if_empty:nF {#1}
+        {
+          \flag_raise:n { str_end }
+          \flag_raise:n { str_error }
+          #1 \s__tl
+          \int_use:N \c_@@_replacement_char_int \s__tl
+        }
+      \__prg_break:
+    }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% Restore the original catcodes of bytes $0$, $254$ and $255$.
+%    \begin{macrocode}
+\group_end:
+%</utf32>
+%    \end{macrocode}
+%
+% \subsubsection{\textsc{iso 8859} support}
+%
+% The \textsc{iso-8859-1} encoding exactly matches with the $256$ first
+% Unicode characters. For other 8-bit encodings of the \textsc{iso-8859}
+% family, we keep track only of differences, and of unassigned bytes.
+%    \begin{macrocode}
+%<*iso88591>
+\@@_declare_eight_bit_encoding:nnn { iso88591 }
+  {
+  }
+  {
+  }
+%</iso88591>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88592>
+\@@_declare_eight_bit_encoding:nnn { iso88592 }
+  {
+    { A1 } { 0104 }
+    { A2 } { 02D8 }
+    { A3 } { 0141 }
+    { A5 } { 013D }
+    { A6 } { 015A }
+    { A9 } { 0160 }
+    { AA } { 015E }
+    { AB } { 0164 }
+    { AC } { 0179 }
+    { AE } { 017D }
+    { AF } { 017B }
+    { B1 } { 0105 }
+    { B2 } { 02DB }
+    { B3 } { 0142 }
+    { B5 } { 013E }
+    { B6 } { 015B }
+    { B7 } { 02C7 }
+    { B9 } { 0161 }
+    { BA } { 015F }
+    { BB } { 0165 }
+    { BC } { 017A }
+    { BD } { 02DD }
+    { BE } { 017E }
+    { BF } { 017C }
+    { C0 } { 0154 }
+    { C3 } { 0102 }
+    { C5 } { 0139 }
+    { C6 } { 0106 }
+    { C8 } { 010C }
+    { CA } { 0118 }
+    { CC } { 011A }
+    { CF } { 010E }
+    { D0 } { 0110 }
+    { D1 } { 0143 }
+    { D2 } { 0147 }
+    { D5 } { 0150 }
+    { D8 } { 0158 }
+    { D9 } { 016E }
+    { DB } { 0170 }
+    { DE } { 0162 }
+    { E0 } { 0155 }
+    { E3 } { 0103 }
+    { E5 } { 013A }
+    { E6 } { 0107 }
+    { E8 } { 010D }
+    { EA } { 0119 }
+    { EC } { 011B }
+    { EF } { 010F }
+    { F0 } { 0111 }
+    { F1 } { 0144 }
+    { F2 } { 0148 }
+    { F5 } { 0151 }
+    { F8 } { 0159 }
+    { F9 } { 016F }
+    { FB } { 0171 }
+    { FE } { 0163 }
+    { FF } { 02D9 }
+  }
+  {
+  }
+%</iso88592>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88593>
+\@@_declare_eight_bit_encoding:nnn { iso88593 }
+  {
+    { A1 } { 0126 }
+    { A2 } { 02D8 }
+    { A6 } { 0124 }
+    { A9 } { 0130 }
+    { AA } { 015E }
+    { AB } { 011E }
+    { AC } { 0134 }
+    { AF } { 017B }
+    { B1 } { 0127 }
+    { B6 } { 0125 }
+    { B9 } { 0131 }
+    { BA } { 015F }
+    { BB } { 011F }
+    { BC } { 0135 }
+    { BF } { 017C }
+    { C5 } { 010A }
+    { C6 } { 0108 }
+    { D5 } { 0120 }
+    { D8 } { 011C }
+    { DD } { 016C }
+    { DE } { 015C }
+    { E5 } { 010B }
+    { E6 } { 0109 }
+    { F5 } { 0121 }
+    { F8 } { 011D }
+    { FD } { 016D }
+    { FE } { 015D }
+    { FF } { 02D9 }
+  }
+  {
+    { A5 }
+    { AE }
+    { BE }
+    { C3 }
+    { D0 }
+    { E3 }
+    { F0 }
+  }
+%</iso88593>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88594>
+\@@_declare_eight_bit_encoding:nnn { iso88594 }
+  {
+    { A1 } { 0104 }
+    { A2 } { 0138 }
+    { A3 } { 0156 }
+    { A5 } { 0128 }
+    { A6 } { 013B }
+    { A9 } { 0160 }
+    { AA } { 0112 }
+    { AB } { 0122 }
+    { AC } { 0166 }
+    { AE } { 017D }
+    { B1 } { 0105 }
+    { B2 } { 02DB }
+    { B3 } { 0157 }
+    { B5 } { 0129 }
+    { B6 } { 013C }
+    { B7 } { 02C7 }
+    { B9 } { 0161 }
+    { BA } { 0113 }
+    { BB } { 0123 }
+    { BC } { 0167 }
+    { BD } { 014A }
+    { BE } { 017E }
+    { BF } { 014B }
+    { C0 } { 0100 }
+    { C7 } { 012E }
+    { C8 } { 010C }
+    { CA } { 0118 }
+    { CC } { 0116 }
+    { CF } { 012A }
+    { D0 } { 0110 }
+    { D1 } { 0145 }
+    { D2 } { 014C }
+    { D3 } { 0136 }
+    { D9 } { 0172 }
+    { DD } { 0168 }
+    { DE } { 016A }
+    { E0 } { 0101 }
+    { E7 } { 012F }
+    { E8 } { 010D }
+    { EA } { 0119 }
+    { EC } { 0117 }
+    { EF } { 012B }
+    { F0 } { 0111 }
+    { F1 } { 0146 }
+    { F2 } { 014D }
+    { F3 } { 0137 }
+    { F9 } { 0173 }
+    { FD } { 0169 }
+    { FE } { 016B }
+    { FF } { 02D9 }
+  }
+  {
+  }
+%</iso88594>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88595>
+\@@_declare_eight_bit_encoding:nnn { iso88595 }
+  {
+    { A1 } { 0401 }
+    { A2 } { 0402 }
+    { A3 } { 0403 }
+    { A4 } { 0404 }
+    { A5 } { 0405 }
+    { A6 } { 0406 }
+    { A7 } { 0407 }
+    { A8 } { 0408 }
+    { A9 } { 0409 }
+    { AA } { 040A }
+    { AB } { 040B }
+    { AC } { 040C }
+    { AE } { 040E }
+    { AF } { 040F }
+    { B0 } { 0410 }
+    { B1 } { 0411 }
+    { B2 } { 0412 }
+    { B3 } { 0413 }
+    { B4 } { 0414 }
+    { B5 } { 0415 }
+    { B6 } { 0416 }
+    { B7 } { 0417 }
+    { B8 } { 0418 }
+    { B9 } { 0419 }
+    { BA } { 041A }
+    { BB } { 041B }
+    { BC } { 041C }
+    { BD } { 041D }
+    { BE } { 041E }
+    { BF } { 041F }
+    { C0 } { 0420 }
+    { C1 } { 0421 }
+    { C2 } { 0422 }
+    { C3 } { 0423 }
+    { C4 } { 0424 }
+    { C5 } { 0425 }
+    { C6 } { 0426 }
+    { C7 } { 0427 }
+    { C8 } { 0428 }
+    { C9 } { 0429 }
+    { CA } { 042A }
+    { CB } { 042B }
+    { CC } { 042C }
+    { CD } { 042D }
+    { CE } { 042E }
+    { CF } { 042F }
+    { D0 } { 0430 }
+    { D1 } { 0431 }
+    { D2 } { 0432 }
+    { D3 } { 0433 }
+    { D4 } { 0434 }
+    { D5 } { 0435 }
+    { D6 } { 0436 }
+    { D7 } { 0437 }
+    { D8 } { 0438 }
+    { D9 } { 0439 }
+    { DA } { 043A }
+    { DB } { 043B }
+    { DC } { 043C }
+    { DD } { 043D }
+    { DE } { 043E }
+    { DF } { 043F }
+    { E0 } { 0440 }
+    { E1 } { 0441 }
+    { E2 } { 0442 }
+    { E3 } { 0443 }
+    { E4 } { 0444 }
+    { E5 } { 0445 }
+    { E6 } { 0446 }
+    { E7 } { 0447 }
+    { E8 } { 0448 }
+    { E9 } { 0449 }
+    { EA } { 044A }
+    { EB } { 044B }
+    { EC } { 044C }
+    { ED } { 044D }
+    { EE } { 044E }
+    { EF } { 044F }
+    { F0 } { 2116 }
+    { F1 } { 0451 }
+    { F2 } { 0452 }
+    { F3 } { 0453 }
+    { F4 } { 0454 }
+    { F5 } { 0455 }
+    { F6 } { 0456 }
+    { F7 } { 0457 }
+    { F8 } { 0458 }
+    { F9 } { 0459 }
+    { FA } { 045A }
+    { FB } { 045B }
+    { FC } { 045C }
+    { FD } { 00A7 }
+    { FE } { 045E }
+    { FF } { 045F }
+  }
+  {
+  }
+%</iso88595>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88596>
+\@@_declare_eight_bit_encoding:nnn { iso88596 }
+  {
+    { AC } { 060C }
+    { BB } { 061B }
+    { BF } { 061F }
+    { C1 } { 0621 }
+    { C2 } { 0622 }
+    { C3 } { 0623 }
+    { C4 } { 0624 }
+    { C5 } { 0625 }
+    { C6 } { 0626 }
+    { C7 } { 0627 }
+    { C8 } { 0628 }
+    { C9 } { 0629 }
+    { CA } { 062A }
+    { CB } { 062B }
+    { CC } { 062C }
+    { CD } { 062D }
+    { CE } { 062E }
+    { CF } { 062F }
+    { D0 } { 0630 }
+    { D1 } { 0631 }
+    { D2 } { 0632 }
+    { D3 } { 0633 }
+    { D4 } { 0634 }
+    { D5 } { 0635 }
+    { D6 } { 0636 }
+    { D7 } { 0637 }
+    { D8 } { 0638 }
+    { D9 } { 0639 }
+    { DA } { 063A }
+    { E0 } { 0640 }
+    { E1 } { 0641 }
+    { E2 } { 0642 }
+    { E3 } { 0643 }
+    { E4 } { 0644 }
+    { E5 } { 0645 }
+    { E6 } { 0646 }
+    { E7 } { 0647 }
+    { E8 } { 0648 }
+    { E9 } { 0649 }
+    { EA } { 064A }
+    { EB } { 064B }
+    { EC } { 064C }
+    { ED } { 064D }
+    { EE } { 064E }
+    { EF } { 064F }
+    { F0 } { 0650 }
+    { F1 } { 0651 }
+    { F2 } { 0652 }
+  }
+  {
+    { A1 }
+    { A2 }
+    { A3 }
+    { A5 }
+    { A6 }
+    { A7 }
+    { A8 }
+    { A9 }
+    { AA }
+    { AB }
+    { AE }
+    { AF }
+    { B0 }
+    { B1 }
+    { B2 }
+    { B3 }
+    { B4 }
+    { B5 }
+    { B6 }
+    { B7 }
+    { B8 }
+    { B9 }
+    { BA }
+    { BC }
+    { BD }
+    { BE }
+    { C0 }
+    { DB }
+    { DC }
+    { DD }
+    { DE }
+    { DF }
+  }
+%</iso88596>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88597>
+\@@_declare_eight_bit_encoding:nnn { iso88597 }
+  {
+    { A1 } { 2018 }
+    { A2 } { 2019 }
+    { A4 } { 20AC }
+    { A5 } { 20AF }
+    { AA } { 037A }
+    { AF } { 2015 }
+    { B4 } { 0384 }
+    { B5 } { 0385 }
+    { B6 } { 0386 }
+    { B8 } { 0388 }
+    { B9 } { 0389 }
+    { BA } { 038A }
+    { BC } { 038C }
+    { BE } { 038E }
+    { BF } { 038F }
+    { C0 } { 0390 }
+    { C1 } { 0391 }
+    { C2 } { 0392 }
+    { C3 } { 0393 }
+    { C4 } { 0394 }
+    { C5 } { 0395 }
+    { C6 } { 0396 }
+    { C7 } { 0397 }
+    { C8 } { 0398 }
+    { C9 } { 0399 }
+    { CA } { 039A }
+    { CB } { 039B }
+    { CC } { 039C }
+    { CD } { 039D }
+    { CE } { 039E }
+    { CF } { 039F }
+    { D0 } { 03A0 }
+    { D1 } { 03A1 }
+    { D3 } { 03A3 }
+    { D4 } { 03A4 }
+    { D5 } { 03A5 }
+    { D6 } { 03A6 }
+    { D7 } { 03A7 }
+    { D8 } { 03A8 }
+    { D9 } { 03A9 }
+    { DA } { 03AA }
+    { DB } { 03AB }
+    { DC } { 03AC }
+    { DD } { 03AD }
+    { DE } { 03AE }
+    { DF } { 03AF }
+    { E0 } { 03B0 }
+    { E1 } { 03B1 }
+    { E2 } { 03B2 }
+    { E3 } { 03B3 }
+    { E4 } { 03B4 }
+    { E5 } { 03B5 }
+    { E6 } { 03B6 }
+    { E7 } { 03B7 }
+    { E8 } { 03B8 }
+    { E9 } { 03B9 }
+    { EA } { 03BA }
+    { EB } { 03BB }
+    { EC } { 03BC }
+    { ED } { 03BD }
+    { EE } { 03BE }
+    { EF } { 03BF }
+    { F0 } { 03C0 }
+    { F1 } { 03C1 }
+    { F2 } { 03C2 }
+    { F3 } { 03C3 }
+    { F4 } { 03C4 }
+    { F5 } { 03C5 }
+    { F6 } { 03C6 }
+    { F7 } { 03C7 }
+    { F8 } { 03C8 }
+    { F9 } { 03C9 }
+    { FA } { 03CA }
+    { FB } { 03CB }
+    { FC } { 03CC }
+    { FD } { 03CD }
+    { FE } { 03CE }
+  }
+  {
+    { AE }
+    { D2 }
+  }
+%</iso88597>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88598>
+\@@_declare_eight_bit_encoding:nnn { iso88598 }
+  {
+    { AA } { 00D7 }
+    { BA } { 00F7 }
+    { DF } { 2017 }
+    { E0 } { 05D0 }
+    { E1 } { 05D1 }
+    { E2 } { 05D2 }
+    { E3 } { 05D3 }
+    { E4 } { 05D4 }
+    { E5 } { 05D5 }
+    { E6 } { 05D6 }
+    { E7 } { 05D7 }
+    { E8 } { 05D8 }
+    { E9 } { 05D9 }
+    { EA } { 05DA }
+    { EB } { 05DB }
+    { EC } { 05DC }
+    { ED } { 05DD }
+    { EE } { 05DE }
+    { EF } { 05DF }
+    { F0 } { 05E0 }
+    { F1 } { 05E1 }
+    { F2 } { 05E2 }
+    { F3 } { 05E3 }
+    { F4 } { 05E4 }
+    { F5 } { 05E5 }
+    { F6 } { 05E6 }
+    { F7 } { 05E7 }
+    { F8 } { 05E8 }
+    { F9 } { 05E9 }
+    { FA } { 05EA }
+    { FD } { 200E }
+    { FE } { 200F }
+  }
+  {
+    { A1 }
+    { BF }
+    { C0 }
+    { C1 }
+    { C2 }
+    { C3 }
+    { C4 }
+    { C5 }
+    { C6 }
+    { C7 }
+    { C8 }
+    { C9 }
+    { CA }
+    { CB }
+    { CC }
+    { CD }
+    { CE }
+    { CF }
+    { D0 }
+    { D1 }
+    { D2 }
+    { D3 }
+    { D4 }
+    { D5 }
+    { D6 }
+    { D7 }
+    { D8 }
+    { D9 }
+    { DA }
+    { DB }
+    { DC }
+    { DD }
+    { DE }
+    { FB }
+    { FC }
+  }
+%</iso88598>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso88599>
+\@@_declare_eight_bit_encoding:nnn { iso88599 }
+  {
+    { D0 } { 011E }
+    { DD } { 0130 }
+    { DE } { 015E }
+    { F0 } { 011F }
+    { FD } { 0131 }
+    { FE } { 015F }
+  }
+  {
+  }
+%</iso88599>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso885910>
+\@@_declare_eight_bit_encoding:nnn { iso885910 }
+  {
+    { A1 } { 0104 }
+    { A2 } { 0112 }
+    { A3 } { 0122 }
+    { A4 } { 012A }
+    { A5 } { 0128 }
+    { A6 } { 0136 }
+    { A8 } { 013B }
+    { A9 } { 0110 }
+    { AA } { 0160 }
+    { AB } { 0166 }
+    { AC } { 017D }
+    { AE } { 016A }
+    { AF } { 014A }
+    { B1 } { 0105 }
+    { B2 } { 0113 }
+    { B3 } { 0123 }
+    { B4 } { 012B }
+    { B5 } { 0129 }
+    { B6 } { 0137 }
+    { B8 } { 013C }
+    { B9 } { 0111 }
+    { BA } { 0161 }
+    { BB } { 0167 }
+    { BC } { 017E }
+    { BD } { 2015 }
+    { BE } { 016B }
+    { BF } { 014B }
+    { C0 } { 0100 }
+    { C7 } { 012E }
+    { C8 } { 010C }
+    { CA } { 0118 }
+    { CC } { 0116 }
+    { D1 } { 0145 }
+    { D2 } { 014C }
+    { D7 } { 0168 }
+    { D9 } { 0172 }
+    { E0 } { 0101 }
+    { E7 } { 012F }
+    { E8 } { 010D }
+    { EA } { 0119 }
+    { EC } { 0117 }
+    { F1 } { 0146 }
+    { F2 } { 014D }
+    { F7 } { 0169 }
+    { F9 } { 0173 }
+    { FF } { 0138 }
+  }
+  {
+  }
+%</iso885910>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso885911>
+\@@_declare_eight_bit_encoding:nnn { iso885911 }
+  {
+    { A1 } { 0E01 }
+    { A2 } { 0E02 }
+    { A3 } { 0E03 }
+    { A4 } { 0E04 }
+    { A5 } { 0E05 }
+    { A6 } { 0E06 }
+    { A7 } { 0E07 }
+    { A8 } { 0E08 }
+    { A9 } { 0E09 }
+    { AA } { 0E0A }
+    { AB } { 0E0B }
+    { AC } { 0E0C }
+    { AD } { 0E0D }
+    { AE } { 0E0E }
+    { AF } { 0E0F }
+    { B0 } { 0E10 }
+    { B1 } { 0E11 }
+    { B2 } { 0E12 }
+    { B3 } { 0E13 }
+    { B4 } { 0E14 }
+    { B5 } { 0E15 }
+    { B6 } { 0E16 }
+    { B7 } { 0E17 }
+    { B8 } { 0E18 }
+    { B9 } { 0E19 }
+    { BA } { 0E1A }
+    { BB } { 0E1B }
+    { BC } { 0E1C }
+    { BD } { 0E1D }
+    { BE } { 0E1E }
+    { BF } { 0E1F }
+    { C0 } { 0E20 }
+    { C1 } { 0E21 }
+    { C2 } { 0E22 }
+    { C3 } { 0E23 }
+    { C4 } { 0E24 }
+    { C5 } { 0E25 }
+    { C6 } { 0E26 }
+    { C7 } { 0E27 }
+    { C8 } { 0E28 }
+    { C9 } { 0E29 }
+    { CA } { 0E2A }
+    { CB } { 0E2B }
+    { CC } { 0E2C }
+    { CD } { 0E2D }
+    { CE } { 0E2E }
+    { CF } { 0E2F }
+    { D0 } { 0E30 }
+    { D1 } { 0E31 }
+    { D2 } { 0E32 }
+    { D3 } { 0E33 }
+    { D4 } { 0E34 }
+    { D5 } { 0E35 }
+    { D6 } { 0E36 }
+    { D7 } { 0E37 }
+    { D8 } { 0E38 }
+    { D9 } { 0E39 }
+    { DA } { 0E3A }
+    { DF } { 0E3F }
+    { E0 } { 0E40 }
+    { E1 } { 0E41 }
+    { E2 } { 0E42 }
+    { E3 } { 0E43 }
+    { E4 } { 0E44 }
+    { E5 } { 0E45 }
+    { E6 } { 0E46 }
+    { E7 } { 0E47 }
+    { E8 } { 0E48 }
+    { E9 } { 0E49 }
+    { EA } { 0E4A }
+    { EB } { 0E4B }
+    { EC } { 0E4C }
+    { ED } { 0E4D }
+    { EE } { 0E4E }
+    { EF } { 0E4F }
+    { F0 } { 0E50 }
+    { F1 } { 0E51 }
+    { F2 } { 0E52 }
+    { F3 } { 0E53 }
+    { F4 } { 0E54 }
+    { F5 } { 0E55 }
+    { F6 } { 0E56 }
+    { F7 } { 0E57 }
+    { F8 } { 0E58 }
+    { F9 } { 0E59 }
+    { FA } { 0E5A }
+    { FB } { 0E5B }
+  }
+  {
+    { DB }
+    { DC }
+    { DD }
+    { DE }
+  }
+%</iso885911>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso885913>
+\@@_declare_eight_bit_encoding:nnn { iso885913 }
+  {
+    { A1 } { 201D }
+    { A5 } { 201E }
+    { A8 } { 00D8 }
+    { AA } { 0156 }
+    { AF } { 00C6 }
+    { B4 } { 201C }
+    { B8 } { 00F8 }
+    { BA } { 0157 }
+    { BF } { 00E6 }
+    { C0 } { 0104 }
+    { C1 } { 012E }
+    { C2 } { 0100 }
+    { C3 } { 0106 }
+    { C6 } { 0118 }
+    { C7 } { 0112 }
+    { C8 } { 010C }
+    { CA } { 0179 }
+    { CB } { 0116 }
+    { CC } { 0122 }
+    { CD } { 0136 }
+    { CE } { 012A }
+    { CF } { 013B }
+    { D0 } { 0160 }
+    { D1 } { 0143 }
+    { D2 } { 0145 }
+    { D4 } { 014C }
+    { D8 } { 0172 }
+    { D9 } { 0141 }
+    { DA } { 015A }
+    { DB } { 016A }
+    { DD } { 017B }
+    { DE } { 017D }
+    { E0 } { 0105 }
+    { E1 } { 012F }
+    { E2 } { 0101 }
+    { E3 } { 0107 }
+    { E6 } { 0119 }
+    { E7 } { 0113 }
+    { E8 } { 010D }
+    { EA } { 017A }
+    { EB } { 0117 }
+    { EC } { 0123 }
+    { ED } { 0137 }
+    { EE } { 012B }
+    { EF } { 013C }
+    { F0 } { 0161 }
+    { F1 } { 0144 }
+    { F2 } { 0146 }
+    { F4 } { 014D }
+    { F8 } { 0173 }
+    { F9 } { 0142 }
+    { FA } { 015B }
+    { FB } { 016B }
+    { FD } { 017C }
+    { FE } { 017E }
+    { FF } { 2019 }
+  }
+  {
+  }
+%</iso885913>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso885914>
+\@@_declare_eight_bit_encoding:nnn { iso885914 }
+  {
+    { A1 } { 1E02 }
+    { A2 } { 1E03 }
+    { A4 } { 010A }
+    { A5 } { 010B }
+    { A6 } { 1E0A }
+    { A8 } { 1E80 }
+    { AA } { 1E82 }
+    { AB } { 1E0B }
+    { AC } { 1EF2 }
+    { AF } { 0178 }
+    { B0 } { 1E1E }
+    { B1 } { 1E1F }
+    { B2 } { 0120 }
+    { B3 } { 0121 }
+    { B4 } { 1E40 }
+    { B5 } { 1E41 }
+    { B7 } { 1E56 }
+    { B8 } { 1E81 }
+    { B9 } { 1E57 }
+    { BA } { 1E83 }
+    { BB } { 1E60 }
+    { BC } { 1EF3 }
+    { BD } { 1E84 }
+    { BE } { 1E85 }
+    { BF } { 1E61 }
+    { D0 } { 0174 }
+    { D7 } { 1E6A }
+    { DE } { 0176 }
+    { F0 } { 0175 }
+    { F7 } { 1E6B }
+    { FE } { 0177 }
+  }
+  {
+  }
+%</iso885914>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso885915>
+\@@_declare_eight_bit_encoding:nnn { iso885915 }
+  {
+    { A4 } { 20AC }
+    { A6 } { 0160 }
+    { A8 } { 0161 }
+    { B4 } { 017D }
+    { B8 } { 017E }
+    { BC } { 0152 }
+    { BD } { 0153 }
+    { BE } { 0178 }
+  }
+  {
+  }
+%</iso885915>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*iso885916>
+\@@_declare_eight_bit_encoding:nnn { iso885916 }
+  {
+    { A1 } { 0104 }
+    { A2 } { 0105 }
+    { A3 } { 0141 }
+    { A4 } { 20AC }
+    { A5 } { 201E }
+    { A6 } { 0160 }
+    { A8 } { 0161 }
+    { AA } { 0218 }
+    { AC } { 0179 }
+    { AE } { 017A }
+    { AF } { 017B }
+    { B2 } { 010C }
+    { B3 } { 0142 }
+    { B4 } { 017D }
+    { B5 } { 201D }
+    { B8 } { 017E }
+    { B9 } { 010D }
+    { BA } { 0219 }
+    { BC } { 0152 }
+    { BD } { 0153 }
+    { BE } { 0178 }
+    { BF } { 017C }
+    { C3 } { 0102 }
+    { C5 } { 0106 }
+    { D0 } { 0110 }
+    { D1 } { 0143 }
+    { D5 } { 0150 }
+    { D7 } { 015A }
+    { D8 } { 0170 }
+    { DD } { 0118 }
+    { DE } { 021A }
+    { E3 } { 0103 }
+    { E5 } { 0107 }
+    { F0 } { 0111 }
+    { F1 } { 0144 }
+    { F5 } { 0151 }
+    { F7 } { 015B }
+    { F8 } { 0171 }
+    { FD } { 0119 }
+    { FE } { 021B }
+  }
+  {
+  }
+%</iso885916>
+%    \end{macrocode}
+%
+% \end{implementation}
+%
+% \PrintIndex
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx
index ea6c38e6564..7d42697daab 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str-format.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3str-format.dtx Copyright (C) 2012 The LaTeX3 Project
+%% File: l3str-format.dtx Copyright (C) 2012-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -100,7 +100,9 @@
 %     data should be formatted.  The list of allowed \meta{styles}
 %     depends on the type.
 % \end{itemize}
-% The choice of \meta{alignment} |=| is not implemented yet.
+% The choice of \meta{alignment} |=| is only valid for numeric types: in
+% this case the padding is inserted between the sign and the rest of the
+% number.
 %
 % \section{Formatting various data-types}
 %
@@ -173,7 +175,7 @@
 %    \end{macrocode}
 %
 %    \begin{macrocode}
-%<@@=str>
+%<@@=str_format>
 %    \end{macrocode}
 %
 %    \begin{macrocode}
@@ -201,11 +203,11 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_if_digit:NTF}
+% \begin{macro}[aux, EXP]{\@@_if_digit:NTF}
 %   Here we expect |#1| to be a character with category other, or
 %   \cs{s__stop}.
 %    \begin{macrocode}
-\prg_new_conditional:Npnn \@@_format_if_digit:N #1 { TF }
+\prg_new_conditional:Npnn \@@_if_digit:N #1 { TF }
   {
     \if_int_compare:w \c_nine < 1 #1 \exp_stop_f:
       \prg_return_true: \else: \prg_return_false: \fi:
@@ -214,27 +216,50 @@
 % \end{macro}
 %
 % \begin{macro}[aux, EXP]
-%   {\@@_format_put:nw, \@@_format_put:ow, \@@_format_put:fw}
+%   {\@@_put:nw, \@@_put:ow, \@@_put:fw}
 %   Put |#1| after an \cs{s__stop} delimiter.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_put:nw #1 #2 \s__stop { #2 \s__stop #1 }
-\cs_generate_variant:Nn \@@_format_put:nw { o , f }
+\cs_new:Npn \@@_put:nw #1 #2 \s__stop { #2 \s__stop #1 }
+\cs_generate_variant:Nn \@@_put:nw { o , f }
 %    \end{macrocode}
 % \end{macro}
 %
+% \begin{macro}[aux, EXP, TF]{\@@_if_in:nN}
+% \begin{macro}[aux, EXP]{\@@_if_in_aux:NN}
+%   A copy of \cs{__str_if_contains_char:nNTF} to avoid relying on
+%   this weird internal string function.
+%    \begin{macrocode}
+\prg_new_conditional:Npnn \@@_if_in:nN #1#2 { TF }
+  {
+    \@@_if_in_aux:NN #2 #1
+      { #2 \prg_return_false: \exp_after:wN \__prg_break: \else: }
+    \__prg_break_point:
+  }
+\cs_new:Npn \@@_if_in_aux:NN #1#2
+  {
+    \if_charcode:w #1 #2
+      \prg_return_true:
+      \exp_after:wN \__prg_break:
+    \fi:
+    \@@_if_in_aux:NN #1
+  }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
 % \subsection{Parsing a format specification}
 %
-% \begin{macro}[aux, EXP]{\@@_format_parse:n}
+% \begin{macro}[aux, EXP]{\@@_parse:n}
 % \begin{macro}[aux, EXP]
 %   {
-%     \@@_format_parse_auxi:NN,
-%     \@@_format_parse_auxii:nN,
-%     \@@_format_parse_auxiii:nN,
-%     \@@_format_parse_auxiv:nwN,
-%     \@@_format_parse_auxv:nN,
-%     \@@_format_parse_auxvi:nwN,
-%     \@@_format_parse_auxvii:nN,
-%     \@@_format_parse_end:nwn,
+%     \@@_parse_auxi:NN,
+%     \@@_parse_auxii:nN,
+%     \@@_parse_auxiii:nN,
+%     \@@_parse_auxiv:nwN,
+%     \@@_parse_auxv:nN,
+%     \@@_parse_auxvi:nwN,
+%     \@@_parse_auxvii:nN,
+%     \@@_parse_end:nwn,
 %   }
 %   The goal is to parse
 %   \begin{equation*}
@@ -242,59 +267,59 @@
 %     [\meta{sign}] [\meta{width}] [.\meta{precision}] [\meta{style}]
 %   \end{equation*}
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_parse:n #1
+\cs_new:Npn \@@_parse:n #1
   {
-    \exp_last_unbraced:Nf \@@_format_parse_auxi:NN
-      \@@_to_other:n {#1} \s__stop \s__stop {#1}
+    \exp_last_unbraced:Nf \@@_parse_auxi:NN
+      \__str_to_other:n {#1} \s__stop \s__stop {#1}
   }
-\cs_new:Npx \@@_format_parse_auxi:NN #1#2
+\cs_new:Npx \@@_parse_auxi:NN #1#2
   {
-    \exp_not:N \@@_if_contains_char:nNTF { < > = ^ } #2
-      { \exp_not:N \@@_format_parse_auxiii:nN { #1 #2 } }
+    \exp_not:N \@@_if_in:nNTF { < > = ^ } #2
+      { \exp_not:N \@@_parse_auxiii:nN { #1 #2 } }
       {
-        \exp_not:N \@@_format_parse_auxii:nN
+        \exp_not:N \@@_parse_auxii:nN
           { \c_catcode_other_space_tl } #1 #2
       }
   }
-\cs_new:Npn \@@_format_parse_auxii:nN #1#2
+\cs_new:Npn \@@_parse_auxii:nN #1#2
   {
-    \@@_if_contains_char:nNTF { < > = ^ } #2
-      { \@@_format_parse_auxiii:nN { #1 #2 } }
-      { \@@_format_parse_auxiii:nN { #1 ? } #2 }
+    \@@_if_in:nNTF { < > = ^ } #2
+      { \@@_parse_auxiii:nN { #1 #2 } }
+      { \@@_parse_auxiii:nN { #1 ? } #2 }
   }
-\cs_new:Npx \@@_format_parse_auxiii:nN #1#2
+\cs_new:Npx \@@_parse_auxiii:nN #1#2
   {
-    \exp_not:N \@@_if_contains_char:nNTF
+    \exp_not:N \@@_if_in:nNTF
       { + - \c_catcode_other_space_tl }
       #2
-      { \exp_not:N \@@_format_parse_auxiv:nwN { #1 #2 } ; }
-      { \exp_not:N \@@_format_parse_auxiv:nwN { #1 ? } ; #2 }
+      { \exp_not:N \@@_parse_auxiv:nwN { #1 #2 } ; }
+      { \exp_not:N \@@_parse_auxiv:nwN { #1 ? } ; #2 }
   }
-\cs_new:Npn \@@_format_parse_auxiv:nwN #1#2; #3
+\cs_new:Npn \@@_parse_auxiv:nwN #1#2; #3
   {
-    \@@_format_if_digit:NTF #3
-      { \@@_format_parse_auxiv:nwN {#1} #2 #3 ; }
-      { \@@_format_parse_auxv:nN { #1 {#2} } #3 }
+    \@@_if_digit:NTF #3
+      { \@@_parse_auxiv:nwN {#1} #2 #3 ; }
+      { \@@_parse_auxv:nN { #1 {#2} } #3 }
   }
-\cs_new:Npn \@@_format_parse_auxv:nN #1#2
+\cs_new:Npn \@@_parse_auxv:nN #1#2
   {
     \token_if_eq_charcode:NNTF . #2
-      { \@@_format_parse_auxvi:nwN {#1} 0 ; }
-      { \@@_format_parse_auxvii:nN { #1 { } } #2 }
+      { \@@_parse_auxvi:nwN {#1} 0 ; }
+      { \@@_parse_auxvii:nN { #1 { } } #2 }
   }
-\cs_new:Npn \@@_format_parse_auxvi:nwN #1#2; #3
+\cs_new:Npn \@@_parse_auxvi:nwN #1#2; #3
   {
-    \@@_format_if_digit:NTF #3
-      { \@@_format_parse_auxvi:nwN {#1} #2 #3 ; }
-      { \@@_format_parse_auxvii:nN { #1 {#2} } #3 }
+    \@@_if_digit:NTF #3
+      { \@@_parse_auxvi:nwN {#1} #2 #3 ; }
+      { \@@_parse_auxvii:nN { #1 {#2} } #3 }
   }
-\cs_new:Npn \@@_format_parse_auxvii:nN #1#2
+\cs_new:Npn \@@_parse_auxvii:nN #1#2
   {
     \token_if_eq_meaning:NNTF \s__stop #2
-      { \@@_format_parse_end:nwn { #1 ? } #2 }
-      { \@@_format_parse_end:nwn { #1 #2 } }
+      { \@@_parse_end:nwn { #1 ? } #2 }
+      { \@@_parse_end:nwn { #1 #2 } }
   }
-\cs_new:Npn \@@_format_parse_end:nwn #1 #2 \s__stop \s__stop #3
+\cs_new:Npn \@@_parse_end:nwn #1 #2 \s__stop \s__stop #3
   {
     \tl_if_empty:nF {#2}
       { \__msg_kernel_expandable_error:nnn { str } { invalid-format } {#3} }
@@ -316,40 +341,40 @@
 % padding between the \meta{sign} and the \meta{body}, hence the need to
 % keep those separate.
 %
-% \begin{macro}[aux, EXP]{\@@_format_align_<:nnnN}
+% \begin{macro}[aux, EXP]{\@@_align_<:nnnN}
 %   \begin{quote}
-%     \cs{@@_format_align_<:nnnN} \Arg{body} \Arg{sign} \Arg{width}
+%     \cs{@@_align_<:nnnN} \Arg{body} \Arg{sign} \Arg{width}
 %     \meta{fill}
 %   \end{quote}
 %   Aligning \enquote{\meta{sign} \meta{body}} to the left
 %   entails appending |#4| the correct number of times.  Then convert
 %   the result to a string.
 %    \begin{macrocode}
-\cs_new:cpn { @@_format_align_<:nnnN } #1#2#3#4
+\cs_new:cpn { @@_align_<:nnnN } #1#2#3#4
   {
     \use:nf { #2 #1 }
       {
         \prg_replicate:nn
-          { \int_max:nn { #3 - \@@_count_unsafe:n { #2 #1 } } { 0 } }
+          { \int_max:nn { #3 - \__str_count_unsafe:n { #2 #1 } } { 0 } }
           {#4}
       }
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_align_>:nnnN}
+% \begin{macro}[aux, EXP]{\@@_align_>:nnnN}
 %   \begin{quote}
-%     \cs{@@_format_align_>:nnnN} \Arg{body} \Arg{sign} \Arg{width}
+%     \cs{@@_align_>:nnnN} \Arg{body} \Arg{sign} \Arg{width}
 %     \meta{fill}
 %   \end{quote}
 %   Aligning an \enquote{\meta{sign} \meta{body}} to the right
 %   entails prepending |#4| the correct number of times.  Then convert
 %   the result to a string.
 %    \begin{macrocode}
-\cs_new:cpn { @@_format_align_>:nnnN } #1#2#3#4
+\cs_new:cpn { @@_align_>:nnnN } #1#2#3#4
   {
     \prg_replicate:nn
-      { \int_max:nn { #3 - \@@_count_unsafe:n { #2 #1 } } { 0 } }
+      { \int_max:nn { #3 - \__str_count_unsafe:n { #2 #1 } } { 0 } }
       {#4}
     #2 #1
   }
@@ -357,9 +382,9 @@
 % \end{macro}
 %
 % \begingroup\catcode`\^=12
-% \begin{macro}[aux, EXP]{\@@_format_align_^:nnnN}
+% \begin{macro}[aux, EXP]{\@@_align_^:nnnN}
 %   \begin{quote}
-%     \cs{@@_format_align_^:nnnN} \Arg{body} \Arg{sign} \Arg{width}
+%     \cs{@@_align_^:nnnN} \Arg{body} \Arg{sign} \Arg{width}
 %     \meta{fill}
 %   \end{quote}
 %   Centering \enquote{\meta{sign} \meta{body}} entails
@@ -367,14 +392,14 @@
 %   number of |#4| to be added is odd, we add one more after than
 %   before.
 %    \begin{macrocode}
-\cs_new:cpn { @@_format_align_^:nnnN } #1#2#3#4
+\cs_new:cpn { @@_align_^:nnnN } #1#2#3#4
   {
     \use:fnf
       {
         \prg_replicate:nn
           {
             \int_max:nn \c_zero
-              { #3 - \@@_count_unsafe:n { #2 #1 } - \c_one }
+              { #3 - \__str_count_unsafe:n { #2 #1 } - \c_one }
             / \c_two
           }
           {#4}
@@ -384,7 +409,7 @@
         \prg_replicate:nn
           {
             \int_max:nn \c_zero
-              { #3 - \@@_count_unsafe:n { #2 #1 } }
+              { #3 - \__str_count_unsafe:n { #2 #1 } }
             / \c_two
           }
           {#4}
@@ -394,21 +419,21 @@
 % \end{macro}
 % \endgroup
 %
-% \begin{macro}[aux, EXP]{\@@_format_align_=:nnnN}
+% \begin{macro}[aux, EXP]{\@@_align_=:nnnN}
 %   \begin{quote}
-%     \cs{@@_format_align_=:nnnN} \Arg{body} \Arg{sign} \Arg{width}
+%     \cs{@@_align_=:nnnN} \Arg{body} \Arg{sign} \Arg{width}
 %     \meta{fill}
 %   \end{quote}
 %   The special numeric alignment |=| means that we insert the
 %   appropriate number of copies of |#4| between the \meta{sign} and the
 %   \meta{body}.  Then convert the result to a string.
 %    \begin{macrocode}
-\cs_new:cpn { @@_format_align_=:nnnN } #1#2#3#4
+\cs_new:cpn { @@_align_=:nnnN } #1#2#3#4
   {
     \use:nf {#2}
       {
         \prg_replicate:nn
-          { \int_max:nn { #3 - \@@_count_unsafe:n { #2 #1 } } { 0 } }
+          { \int_max:nn { #3 - \__str_count_unsafe:n { #2 #1 } } { 0 } }
           {#4}
       }
     #1
@@ -420,7 +445,7 @@
 % \subsection{Formatting token lists}
 %
 % \begin{macro}[EXP]{\tl_format:Nn, \tl_format:cn, \tl_format:nn}
-%   Call \cs{@@_format_tl:NNNnnNn} to read the parsed \meta{format
+%   Call \cs{@@_tl:NNNnnNn} to read the parsed \meta{format
 %     specification}.  Then convert the result to a string.
 %    \begin{macrocode}
 \cs_new_nopar:Npn \tl_format:Nn { \exp_args:No \tl_format:nn }
@@ -429,52 +454,52 @@
   {
     \tl_to_str:f
       {
-        \exp_last_unbraced:Nf \@@_format_tl:NNNnnNn
-          { \@@_format_parse:n {#2} }
+        \exp_last_unbraced:Nf \@@_tl:NNNnnNn
+          { \@@_parse:n {#2} }
           {#1}
       }
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_tl:NNNnnNn}
+% \begin{macro}[aux, EXP]{\@@_tl:NNNnnNn}
 %   \begin{quote}
-%     \cs{@@_format_tl:NNNnnNn} \meta{fill} \meta{alignment} \meta{sign}
+%     \cs{@@_tl:NNNnnNn} \meta{fill} \meta{alignment} \meta{sign}
 %     \Arg{width} \Arg{precision} \meta{style} \Arg{token list}
 %   \end{quote}
 %   First check that the \meta{alignment} is not |=|, and set the
 %   default alignment |?| to |<|.  Place the modified information after
 %   a trailing \cs{s__stop} for later retrieval.  Then check that there
 %   was no \meta{sign}.  The width will be useful later, store it after
-%   \cs{s__stop}.  Afterwards, check the \meta{precision}: if it is
-%   empty, we will eventually use the whole string, otherwise we will
-%   only use a substring, starting at the index $1$, and ending at |#5|.
+%   \cs{s__stop}.  Afterwards, store the precision, and the function
+%   \cs{__str_range_unsafe:nnn} that will be used to extract the first
+%   |#5| characters of the string.
 %   There is a need to use the \enquote{unsafe} function, as otherwise
 %   leading spaces would get stripped by |f|-expansion.  Finally, check
 %   that the \meta{style} is |?| or |s|.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_tl:NNNnnNn #1#2#3#4#5#6
+\cs_new:Npn \@@_tl:NNNnnNn #1#2#3#4#5#6
   {
     \token_if_eq_charcode:NNTF #2 =
       {
         \__msg_kernel_expandable_error:nnnn
           { str } { invalid-align-format } {#2} {tl}
-        \@@_format_put:nw { #1 < }
+        \@@_put:nw { #1 < }
       }
       {
         \token_if_eq_charcode:NNTF #2 ?
-          { \@@_format_put:nw { #1 < } }
-          { \@@_format_put:nw { #1 #2 } }
+          { \@@_put:nw { #1 < } }
+          { \@@_put:nw { #1 #2 } }
       }
     \token_if_eq_charcode:NNF #3 ?
       {
         \__msg_kernel_expandable_error:nnnn
           { str } { invalid-sign-format } {#3} {tl}
       }
-    \@@_format_put:nw { {#4} }
+    \@@_put:nw { {#4} }
     \tl_if_empty:nTF {#5}
-      { \@@_format_put:nw { \use:n { } } }
-      { \@@_format_put:nw { \@@_substr_unsafe:nnn { {1} {#5} } } }
+      { \@@_put:nw { \__str_range_unsafe:nnn { {1} {-1} } } }
+      { \@@_put:nw { \__str_range_unsafe:nnn { {1} {#5} } } }
     \token_if_eq_charcode:NNF #6 s
       {
         \token_if_eq_charcode:NNF #6 ?
@@ -483,15 +508,15 @@
               { str } { invalid-style-format } {#6} {tl}
           }
       }
-    \@@_format_tl_s:NNnnNNn
+    \@@_tl_s:NNnnNNn
     \s__stop
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_tl_s:NNnnNNn}
+% \begin{macro}[aux, EXP]{\@@_tl_s:NNnnNNn}
 %   \begin{quote}
-%     \cs{@@_format_tl_s:NNnnNNn} \cs{s__stop} \meta{function}
+%     \cs{@@_tl_s:NNnnNNn} \cs{s__stop} \meta{function}
 %     \Arg{arguments} \Arg{width} \meta{fill} \meta{alignment}
 %     \Arg{token list}
 %   \end{quote}
@@ -499,13 +524,13 @@
 %   that |f|-expanding \meta{function} \Arg{other string}
 %   \meta{arguments} yields the piece of the \meta{other string} that we
 %   want to output.  The \meta{other string} is built from the
-%   \meta{token list} by |f|-expanding \cs{@@_to_other:n}.
+%   \meta{token list} by |f|-expanding \cs{__str_to_other:n}.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_tl_s:NNnnNNn #1#2#3#4#5#6#7
+\cs_new:Npn \@@_tl_s:NNnnNNn #1#2#3#4#5#6#7
   {
     \exp_args:Nc \exp_args:Nf
-      { @@_format_align_#6:nnnN }
-      { \exp_args:Nf #2 { \@@_to_other:n {#7} } #3 }
+      { @@_align_#6:nnnN }
+      { \exp_args:Nf #2 { \__str_to_other:n {#7} } #3 }
       { }
       {#4} #5
   }
@@ -522,29 +547,29 @@
 \cs_new:Npn \seq_format:Nn #1#2
   {
     \tl_to_str:f
-      { \@@_format_seq:of {#1} { \@@_format_parse:n {#2} } }
+      { \@@_seq:of {#1} { \@@_parse:n {#2} } }
   }
 \cs_generate_variant:Nn \seq_format:Nn { c }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_seq:nn, \@@_format_seq:of}
+% \begin{macro}[aux, EXP]{\@@_seq:nn, \@@_seq:of}
 %   The first argument is the contents of a \texttt{seq} variable.  The
 %   second is a parsed \meta{format specification}.  Set up the loop.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_seq:nn #1#2
+\cs_new:Npn \@@_seq:nn #1#2
   {
-    \@@_format_seq_loop:nnNn { } {#2}
+    \@@_seq_loop:nnNn { } {#2}
       #1
-      { ? \@@_format_seq_end:w } { }
+      { ? \@@_seq_end:w } { }
   }
-\cs_generate_variant:Nn \@@_format_seq:nn { of }
+\cs_generate_variant:Nn \@@_seq:nn { of }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_seq_loop:nnNn}
+% \begin{macro}[aux, EXP]{\@@_seq_loop:nnNn}
 %   \begin{quote}
-%     \cs{@@_format_seq_loop:nnNn} \Arg{done} \Arg{parsed format}
+%     \cs{@@_seq_loop:nnNn} \Arg{done} \Arg{parsed format}
 %     \cs{__seq_item:n} \Arg{item}
 %   \end{quote}
 %   The first argument is the result of formatting the items read so
@@ -552,52 +577,52 @@
 %   until we reach the end of the sequence, where |\use_none:n #3| ends
 %   the loop.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_seq_loop:nnNn #1#2#3#4
+\cs_new:Npn \@@_seq_loop:nnNn #1#2#3#4
   {
     \use_none:n #3
-    \exp_args:Nf \@@_format_seq_loop:nnNn
-      { \use:nf {#1} { \@@_format_tl:NNNnnNn #2 {#4} } }
+    \exp_args:Nf \@@_seq_loop:nnNn
+      { \use:nf {#1} { \@@_tl:NNNnnNn #2 {#4} } }
       {#2}
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_seq_end:w}
+% \begin{macro}[aux, EXP]{\@@_seq_end:w}
 %   Pick the right piece in the loop above.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_seq_end:w #1#2#3#4 { \use_ii:nnn #3 }
+\cs_new:Npn \@@_seq_end:w #1#2#3#4 { \use_ii:nnn #3 }
 %    \end{macrocode}
 % \end{macro}
 %
 % \subsection{Formatting integers}
 %
 % \begin{macro}[EXP]{\int_format:nn}
-%   Evalute the first argument and feed it to \cs{@@_format_int:nn}.
+%   Evalute the first argument and feed it to \cs{@@_int:nn}.
 %    \begin{macrocode}
 \cs_new:Npn \int_format:nn #1
-  { \exp_args:Nf \@@_format_int:nn { \int_eval:n {#1} } }
+  { \exp_args:Nf \@@_int:nn { \int_eval:n {#1} } }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_int:nn}
+% \begin{macro}[aux, EXP]{\@@_int:nn}
 %   Parse the \meta{format specification} and feed it to
-%   \cs{@@_format_int:NNNnnNn}.  Then convert the result to a string
+%   \cs{@@_int:NNNnnNn}.  Then convert the result to a string
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_int:nn #1#2
+\cs_new:Npn \@@_int:nn #1#2
   {
     \tl_to_str:f
       {
-        \exp_last_unbraced:Nf \@@_format_int:NNNnnNn
-          { \@@_format_parse:n {#2} }
+        \exp_last_unbraced:Nf \@@_int:NNNnnNn
+          { \@@_parse:n {#2} }
           {#1}
       }
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_int:NNNnnNn}
+% \begin{macro}[aux, EXP]{\@@_int:NNNnnNn}
 %   \begin{quote}
-%     \cs{@@_format_int:NNNnnNn} \meta{fill} \meta{alignment}
+%     \cs{@@_int:NNNnnNn} \meta{fill} \meta{alignment}
 %     \meta{sign} \Arg{width} \Arg{precision} \meta{style} \Arg{integer}
 %   \end{quote}
 %   First set the
@@ -611,22 +636,22 @@
 %   the \meta{precision} was absent.  Finally, dispatch depending on the
 %   \meta{style}.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_int:NNNnnNn #1#2#3#4#5#6#7
+\cs_new:Npn \@@_int:NNNnnNn #1#2#3#4#5#6#7
   {
     \token_if_eq_charcode:NNTF #2 ?
-      { \@@_format_put:nw { #1 > } }
-      { \@@_format_put:nw { #1 #2 } }
+      { \@@_put:nw { #1 > } }
+      { \@@_put:nw { #1 #2 } }
     \int_compare:nNnTF {#7} < \c_zero
-      { \@@_format_put:nw { - } }
+      { \@@_put:nw { - } }
       {
         \str_case:nnn {#3}
           {
-            { ~ } { \@@_format_put:ow { \c_catcode_other_space_tl } }
-            { + } { \@@_format_put:nw { + } }
+            { ~ } { \@@_put:ow { \c_catcode_other_space_tl } }
+            { + } { \@@_put:nw { + } }
           }
-          { \@@_format_put:nw { { } } }
+          { \@@_put:nw { { } } }
       }
-    \@@_format_put:nw { {#4} }
+    \@@_put:nw { {#4} }
     \tl_if_empty:nF {#5}
       {
         \__msg_kernel_expandable_error:nnnn
@@ -634,25 +659,25 @@
       }
     \str_case:nnn {#6}
       {
-        { ? } { \@@_format_int:NwnnNNn \use:n }
-        { d } { \@@_format_int:NwnnNNn \use:n }
-        { b } { \@@_format_int:NwnnNNn \int_to_binary:n }
-        { o } { \@@_format_int:NwnnNNn \int_to_octal:n }
-        { X } { \@@_format_int:NwnnNNn \int_to_hexadecimal:n }
+        { ? } { \@@_int:NwnnNNn \use:n }
+        { d } { \@@_int:NwnnNNn \use:n }
+        { b } { \@@_int:NwnnNNn \int_to_binary:n }
+        { o } { \@@_int:NwnnNNn \int_to_octal:n }
+        { X } { \@@_int:NwnnNNn \int_to_hexadecimal:n }
       }
       {
         \__msg_kernel_expandable_error:nnnn
           { str } { invalid-style-format } {#6} { int }
-        \@@_format_int:NwnnNNn \use:n
+        \@@_int:NwnnNNn \use:n
       }
     \s__stop {#7}
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_int:NwnnNNn}
+% \begin{macro}[aux, EXP]{\@@_int:NwnnNNn}
 %   \begin{quote}
-%     \cs{@@_format_int:NwnnNNn} \meta{function} \cs{s__stop}
+%     \cs{@@_int:NwnnNNn} \meta{function} \cs{s__stop}
 %     \Arg{width} \Arg{sign} \meta{fill} \meta{alignment} \Arg{integer}
 %   \end{quote}
 %   Use the |format_align| function corresponding to the
@@ -665,48 +690,48 @@
 %     \item the \meta{fill} character.
 %   \end{itemize}
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_int:NwnnNNn #1#2 \s__stop #3#4#5#6#7
+\cs_new:Npn \@@_int:NwnnNNn #1#2 \s__stop #3#4#5#6#7
   {
     \exp_args:Nc \exp_args:Nf
-      { @@_format_align_#6:nnnN }
+      { @@_align_#6:nnnN }
       { #1 { \int_abs:n {#7} } }
       {#4}
       {#3} #5
   }
 %    \end{macrocode}
-% ^^A todo: note similarity with  \@@_format_tl_s:NNnnNNn
+% ^^A todo: note similarity with  \@@_tl_s:NNnnNNn
 % \end{macro}
 %
 % \subsection{Formatting floating points}
 %
 % \begin{macro}[EXP]{\fp_format:nn}
 %   Evalute the first argument to an internal floating point number, and
-%   feed it to \cs{@@_format_fp:nn}.
+%   feed it to \cs{@@_fp:nn}.
 %    \begin{macrocode}
 \cs_new:Npn \fp_format:nn #1
-  { \exp_args:Nf \@@_format_fp:nn { \__fp_parse:n {#1} } }
+  { \exp_args:Nf \@@_fp:nn { \__fp_parse:n {#1} } }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp:nn}
+% \begin{macro}[aux, EXP]{\@@_fp:nn}
 %   Parse the \meta{format specification} and feed it to
-%   \cs{@@_format_fp:NNNnnNn}.  Then convert the result to a string
+%   \cs{@@_fp:NNNnnNn}.  Then convert the result to a string
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_fp:nn #1#2
+\cs_new:Npn \@@_fp:nn #1#2
   {
     \tl_to_str:f
       {
-        \exp_last_unbraced:Nf \@@_format_fp:NNNnnNw
-          { \@@_format_parse:n {#2} }
+        \exp_last_unbraced:Nf \@@_fp:NNNnnNw
+          { \@@_parse:n {#2} }
           #1
       }
   }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp:NNNnnNw}
+% \begin{macro}[aux, EXP]{\@@_fp:NNNnnNw}
 %   \begin{quote}
-%     \cs{@@_format_fp:NNNnnNw} \meta{fill} \meta{alignment}
+%     \cs{@@_fp:NNNnnNw} \meta{fill} \meta{alignment}
 %     \meta{format sign} \Arg{width} \Arg{precision} \meta{style}
 %     \cs{s__fp} \cs{__fp_chk:w} \meta{fp type} \meta{fp sign} \meta{fp
 %       body} |;|
@@ -723,37 +748,37 @@
 %   (default precision).  Finally, dispatch depending on the
 %   \meta{style}.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_fp:NNNnnNw
+\cs_new:Npn \@@_fp:NNNnnNw
     #1#2#3#4#5#6 \s__fp \__fp_chk:w #7 #8
   {
     \token_if_eq_charcode:NNTF #2 ?
-      { \@@_format_put:nw { #1 > } }
-      { \@@_format_put:nw { #1 #2 } }
+      { \@@_put:nw { #1 > } }
+      { \@@_put:nw { #1 #2 } }
     \token_if_eq_meaning:NNTF 2 #8
-      { \@@_format_put:nw { - } }
+      { \@@_put:nw { - } }
       {
         \str_case:nnn {#3}
           {
-            { ~ } { \@@_format_put:ow { \c_catcode_other_space_tl } }
-            { + } { \@@_format_put:nw { + } }
+            { ~ } { \@@_put:ow { \c_catcode_other_space_tl } }
+            { + } { \@@_put:nw { + } }
           }
-          { \@@_format_put:nw { { } } }
+          { \@@_put:nw { { } } }
       }
-    \@@_format_put:nw { {#4} }
+    \@@_put:nw { {#4} }
     \tl_if_empty:nTF {#5}
-      { \@@_format_put:nw { { 6} } }
-      { \@@_format_put:nw { {#5} } }
+      { \@@_put:nw { { 6} } }
+      { \@@_put:nw { {#5} } }
     \str_case:nnn {#6}
       {
-        { e } { \@@_format_fp:wnnnNNw \@@_format_fp_e:wn }
-        { f } { \@@_format_fp:wnnnNNw \@@_format_fp_f:wn }
-        { g } { \@@_format_fp:wnnnNNw \@@_format_fp_g:wn }
-        { ? } { \@@_format_fp:wnnnNNw \@@_format_fp_g:wn }
+        { e } { \@@_fp:wnnnNNw \@@_fp_e:wn }
+        { f } { \@@_fp:wnnnNNw \@@_fp_f:wn }
+        { g } { \@@_fp:wnnnNNw \@@_fp_g:wn }
+        { ? } { \@@_fp:wnnnNNw \@@_fp_g:wn }
       }
       {
         \__msg_kernel_expandable_error:nnnn
           { str } { invalid-style-format } {#6} { fp }
-        \@@_format_fp:wnnnNNw \@@_format_fp_g:wn
+        \@@_fp:wnnnNNw \@@_fp_g:wn
       }
     \s__stop
     \s__fp \__fp_chk:w #7 #8
@@ -761,19 +786,19 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp:wnnnNNw}
+% \begin{macro}[aux, EXP]{\@@_fp:wnnnNNw}
 %   \begin{quote}
-%     \cs{@@_format_fp:wnnnNNw} \meta{formatting function} \cs{s__stop}
+%     \cs{@@_fp:wnnnNNw} \meta{formatting function} \cs{s__stop}
 %     \Arg{precision} \Arg{width} \Arg{sign} \meta{fill}
 %     \meta{alignment} \cs{s__fp} \cs{__fp_chk:w} \meta{fp type}
 %     \meta{fp sign} \meta{fp body} |;|
 %   \end{quote}
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_fp:wnnnNNw
+\cs_new:Npn \@@_fp:wnnnNNw
     #1 \s__stop #2 #3 #4 #5#6 #7 ;
   {
     \exp_args:Nc \exp_args:Nf
-      { @@_format_align_#6:nnnN }
+      { @@_align_#6:nnnN }
       { #1 #7 ; {#2} }
       {#4}
       {#3} #5
@@ -781,17 +806,17 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp_round:wn}
+% \begin{macro}[aux, EXP]{\@@_fp_round:wn}
 %   Round the given floating point (not its absolute value, to play
 %   nicely with unusual rounding modes).
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_fp_round:wn #1 ; #2
+\cs_new:Npn \@@_fp_round:wn #1 ; #2
   { \__fp_parse:n { round ( #1; , #2 - \__fp_exponent:w #1; ) } }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp_e:wn}
-% \begin{macro}[aux, EXP]{\@@_format_fp_e_aux:wn}
+% \begin{macro}[aux, EXP]{\@@_fp_e:wn}
+% \begin{macro}[aux, EXP]{\@@_fp_e_aux:wn}
 %   With the |e| type, first filter out special cases.  In the normal
 %   case, round to |#4+1| significant figures (one before the decimal
 %   separator, |#4| after).
@@ -801,7 +826,7 @@
 \tl_to_lowercase:n
   {
     \group_end:
-    \cs_new:Npn \@@_format_fp_e:wn \s__fp \__fp_chk:w #1#2#3 ; #4
+    \cs_new:Npn \@@_fp_e:wn \s__fp \__fp_chk:w #1#2#3 ; #4
       {
         \int_case:nnn {#1}
           {
@@ -810,26 +835,26 @@
             {3} { nan }
           }
           {
-            \exp_last_unbraced:Nf \@@_format_fp_e_aux:wn
-              \@@_format_fp_round:wn \s__fp \__fp_chk:w #1#2#3 ; { #4 + 1 }
+            \exp_last_unbraced:Nf \@@_fp_e_aux:wn
+              \@@_fp_round:wn \s__fp \__fp_chk:w #1#2#3 ; { #4 + 1 }
               {#4}
           }
       }
-    \cs_new:Npn \@@_format_fp_e_aux:wn
+    \cs_new:Npn \@@_fp_e_aux:wn
         \s__fp \__fp_chk:w #1#2 #3 #4#5#6#7 ; #8
       {
-        \@@_format_put:fw { \int_eval:n { #3 - 1 } }
-        \@@_format_put:nw { e }
+        \@@_put:fw { \int_eval:n { #3 - 1 } }
+        \@@_put:nw { e }
         \int_compare:nNnTF {#8} > \c_sixteen
           {
-            \@@_format_put:fw { \prg_replicate:nn { #8 - \c_fifteen } {0} }
-            \@@_format_put:fw { \use_none:n #4#5#6#7 }
+            \@@_put:fw { \prg_replicate:nn { #8 - \c_fifteen } {0} }
+            \@@_put:fw { \use_none:n #4#5#6#7 }
           }
           {
-            \@@_format_put:fw
-              { \str_substr:nnn { #4#5#6#7 0 } { 2 } { #8 + 1 } }
+            \@@_put:fw
+              { \str_range:nnn { #4#5#6#7 0 } { 2 } { #8 + 1 } }
           }
-        \@@_format_put:fw { \use_i:nnnn #4 . }
+        \@@_put:fw { \use_i:nnnn #4 . }
         \use_none:n \s__stop
       }
   }
@@ -837,12 +862,12 @@
 % \end{macro}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp_f:wn}
-% \begin{macro}[aux, EXP]{\@@_format_fp_f_aux:wwwn}
+% \begin{macro}[aux, EXP]{\@@_fp_f:wn}
+% \begin{macro}[aux, EXP]{\@@_fp_f_aux:wwwn}
 %   With the |f| type, first filter out special cases.  In the normal
 %   case, round to |#4| (absolute) decimal places.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_fp_f:wn \s__fp \__fp_chk:w #1#2#3 ; #4
+\cs_new:Npn \@@_fp_f:wn \s__fp \__fp_chk:w #1#2#3 ; #4
   {
     \int_case:nnn {#1}
       {
@@ -851,25 +876,25 @@
         {3} { nan }
       }
       {
-        \exp_last_unbraced:Nf \@@_format_fp_f_aux:wwwn
+        \exp_last_unbraced:Nf \@@_fp_f_aux:wwwn
           \fp_to_decimal:n
             { abs ( round ( \s__fp \__fp_chk:w #1#2#3 ; , #4 ) ) }
           . . ;
           {#4}
       }
   }
-\cs_new:Npn \@@_format_fp_f_aux:wwwn #1 . #2 . #3 ; #4
+\cs_new:Npn \@@_fp_f_aux:wwwn #1 . #2 . #3 ; #4
   {
     \use:nf
       { #1 . #2 }
-      { \prg_replicate:nn { #4 - \@@_count_unsafe:n {#2} } {0} }
+      { \prg_replicate:nn { #4 - \__str_count_unsafe:n {#2} } {0} }
   }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
 %
-% \begin{macro}[aux, EXP]{\@@_format_fp_g:wn}
-% \begin{macro}[aux, EXP]{\@@_format_fp_g_aux:wn}
+% \begin{macro}[aux, EXP]{\@@_fp_g:wn}
+% \begin{macro}[aux, EXP]{\@@_fp_g_aux:wn}
 %   With the |g| type, first filter out special cases.  In the normal
 %   case, round to |#4| significant figures, then test the exponent: if
 %   $-4\leq \meta{exponent} < \meta{precision}$, use the presentation
@@ -880,7 +905,7 @@
 %   \cs{fp_to_decimal:n} and \cs{fp_to_scientific:n}, acting on the
 %   (absolute value of the) rounded value.
 %    \begin{macrocode}
-\cs_new:Npn \@@_format_fp_g:wn \s__fp \__fp_chk:w #1#2 ; #3
+\cs_new:Npn \@@_fp_g:wn \s__fp \__fp_chk:w #1#2 ; #3
   {
     \int_case:nnn {#1}
       {
@@ -889,13 +914,13 @@
         {3} { nan }
       }
       {
-        \exp_last_unbraced:Nf \@@_format_fp_g_aux:wn
-          \@@_format_fp_round:wn \s__fp \__fp_chk:w #1#2 ;
+        \exp_last_unbraced:Nf \@@_fp_g_aux:wn
+          \@@_fp_round:wn \s__fp \__fp_chk:w #1#2 ;
             { \int_max:nn {1} {#3} }
           { \int_max:nn {1} {#3} }
       }
   }
-\cs_new:Npn \@@_format_fp_g_aux:wn #1; #2
+\cs_new:Npn \@@_fp_g_aux:wn #1; #2
   {
     \int_compare:nNnTF { \__fp_exponent:w #1; } < { -3 }
       { \fp_to_scientific:n }
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.dtx
index 301682c64be..0a4d72afd2f 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3str.dtx Copyright (C) 2011-2012 The LaTeX3 Project
+%% File: l3str.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,14 +35,13 @@
 %
 %<*driver|package>
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3str.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3str.dtx 4452 2013-01-20 10:18:32Z joseph $
   {L3 Experimental strings}
 %</driver|package>
 %<*driver>
 \documentclass[full]{l3doc}
 \usepackage{amsmath}
 \begin{document}
-  \tableofcontents
   \DocInput{\jobname.dtx}
 \end{document}
 %</driver>
@@ -67,8 +66,9 @@
 % \date{Released \ExplFileDate}
 %
 % \maketitle
+% 
+% \tableofcontents
 %
-% \newcommand{\hexnum}[1]{\text{\texttt{\char`\"}#1}}
 % \begin{documentation}
 %
 % \LaTeX3 provides a set of functions to manipulate token lists
@@ -76,42 +76,39 @@
 % characters.
 %
 % String variables are simply specialised token lists, but by convention
-% should be named with the suffix \texttt{\ldots str}. Such variables
+% should be named with the suffix \texttt{\ldots{}str}.  Such variables
 % should contain characters with category code $12$ (other), except
-% spaces, which have category code $10$ (blank space). All the functions
-% in this module first convert their argument to a string for internal
-% processing, and will not treat a token list or the corresponding
-% string representation differently.
+% spaces, which have category code $10$ (blank space).  All the
+% functions in this module which accept a token list argument first
+% convert it to a string using \cs{tl_to_str:n} for internal processing,
+% and will not treat a token list or the corresponding string
+% representation differently.
 %
-% Most functions in this module come in three flavours:
+% Most expandable functions in this module come in three flavours:
 % \begin{itemize}
-%   \item \cs{str_...:N...}, which expect a token list or string
+%   \item \cs{str_...:N}, which expect a token list or string
 %     variable as their argument;
-%   \item \cs{str_...:n...}, taking any token list (or string) as an
+%   \item \cs{str_...:n}, taking any token list (or string) as an
 %     argument;
-%   \item \cs{str_..._ignore_spaces:n...}, which ignores any space
-%     encountered during the operation: these functions are faster than
-%     those which take care of escaping spaces appropriately;
+%   \item \cs{str_..._ignore_spaces:n}, which ignores any space
+%     encountered during the operation: these functions are typically
+%     faster than those which take care of escaping spaces
+%     appropriately.
 % \end{itemize}
 %
 % \section{Building strings}
 %
-% \begin{variable}{\c_max_char_int}
-%   The maximum valid character code, $255$ for pdf\TeX{}, and $1114111$
-%   for \XeTeX{} and \LuaTeX{}.
-% \end{variable}
-%
 % \begin{variable}
 %   {
 %     \c_backslash_str,
-%     \c_lbrace_str,
-%     \c_rbrace_str,
+%     \c_left_brace_str,
+%     \c_right_brace_str,
 %     \c_hash_str,
 %     \c_tilde_str,
 %     \c_percent_str
 %   }
-%   Constant strings, containing a single character, with category code
-%   $12$.  Any character can be accessed as \cs{iow_char:N}
+%   Constant strings, containing a single character token, with category
+%   code $12$.  Any character can be accessed as \cs{iow_char:N}
 %   |\|\meta{character}.
 % \end{variable}
 %
@@ -121,16 +118,31 @@
 %     \cs{tl_to_str:n} \Arg{token list}
 %   \end{syntax}
 %   Converts the \meta{token list} to a \meta{string}, leaving the
-%   resulting tokens in the input stream.
+%   resulting character tokens in the input stream.
 %   \begin{texnote}
-%     The string representation of a token list may depend on the
-%     category codes in effect when it is evaluated, and the value of
-%     the \tn{escapechar}: for instance |\tl_to_str:n {\a}| normally
-%     produces the three character \enquote{backslash},
-%     \enquote{lower-case a}, \enquote{space}, but it may also produce
-%     $1$ or $2$ characters depending on the escape character, and the
-%     category code of \texttt{a}. This impacts almost all functions in
-%     the module, which use \cs{tl_to_str:n} internally.
+%     Converting a \meta{token list} to a \meta{string} yields a
+%     concatenation of the string representations of every token in the
+%     \meta{token list}.
+%     The string representation of a control sequence is
+%     \begin{itemize}
+%       \item an escape character, whose character code is given by the
+%         internal parameter \tn{escapechar}, absent if the
+%         \tn{escapechar} is negative;
+%       \item the control sequence name, as defined by \cs{cs_to_str:N};
+%       \item a space, unless the control sequence name is a single
+%         character whose category at the time of expansion of
+%         \cs{tl_to_str:n} is not \enquote{letter}.
+%     \end{itemize}
+%     The string representation of an explicit character token is that
+%     character, doubled in the case of (explicit) macro parameter
+%     characters (normally |#|).
+%     In particular, the string representation of a token list may
+%     depend on the category codes in effect when it is evaluated, and
+%     the value of the \tn{escapechar}: for instance |\tl_to_str:n {\a}|
+%     normally produces the three character \enquote{backslash},
+%     \enquote{lower-case a}, \enquote{space}, but it may also produce a
+%     single \enquote{lower-case a} if the escape character is negative
+%     and \texttt{a} is currently not a letter.
 %   \end{texnote}
 % \end{function}
 %
@@ -139,7 +151,7 @@
 %     \cs{str_new:N} \meta{str~var}
 %   \end{syntax}
 %   Creates a new \meta{str~var} or raises an error if the name is
-%   already taken. The declaration is global. The \meta{str~var} will
+%   already taken.  The declaration is global.  The \meta{str~var} will
 %   initially be empty.
 % \end{function}
 %
@@ -148,7 +160,7 @@
 %     \cs{str_const:Nn} \meta{str~var} \Arg{token list}
 %   \end{syntax}
 %   Creates a new constant \meta{str~var} or raises an error if the name
-%   is already taken. The value of the \meta{str~var} will be set
+%   is already taken.  The value of the \meta{str~var} will be set
 %   globally to the \meta{token list}, converted to a string.
 % \end{function}
 %
@@ -201,13 +213,12 @@
 %   \begin{syntax}
 %     \cs{str_count:n} \Arg{token list}
 %   \end{syntax}
-%   Leaves the number of tokens in the string representation of
-%   \meta{token list}
-%   in the input stream as an integer denotation. The functions differ
-%   in their treatment of spaces.  In the case of \cs{str_count:N} and
-%   \cs{str_count:n}, all characters including spaces are counted.  The
-%   \cs{str_count_ignore_spaces:n} leaves the number of non-space
-%   characters in the input stream.
+%   Leaves in the input stream the number of characters in the string
+%   representation of \meta{token list}, as an integer denotation.  The
+%   functions differ in their treatment of spaces.  In the case of
+%   \cs{str_count:N} and \cs{str_count:n}, all characters including
+%   spaces are counted.  The \cs{str_count_ignore_spaces:n} function
+%   leaves the number of non-space characters in the input stream.
 % \end{function}
 %
 % \begin{function}[EXP]{\str_count_spaces:N, \str_count_spaces:n}
@@ -226,14 +237,14 @@
 %   \end{syntax}
 %   Converts the \meta{token list} into a \meta{string}.  The first
 %   character in the \meta{string} is then left in the input stream,
-%   with category code \enquote{other}.  The functions differ in their
-%   treatment of spaces.  In the case of \cs{str_head:N} and
-%   \cs{str_head:n}, a leading space is returned with category code $10$
-%   (blank space).  The \cs{str_head_ignore_spaces:n} function leaves
-%   the first non-space character in the input stream.  If the
-%   \meta{token list} is empty (or blank in the case of the
-%   \texttt{_ignore_spaces} variant), then nothing is left on the input
-%   stream.
+%   with category code \enquote{other}.  The functions differ if the
+%   first character is a space: \cs{str_head:N} and \cs{str_head:n}
+%   return a space token with category code~$10$ (blank space), while
+%   the \cs{str_head_ignore_spaces:n} function ignores this space
+%   character and leaves the first non-space character in the input
+%   stream.  If the \meta{string} is empty (or only contains spaces in
+%   the case of the \texttt{_ignore_spaces} function), then nothing is
+%   left on the input stream.
 % \end{function}
 %
 % \begin{function}[EXP]{\str_tail:N, \str_tail:n, \str_tail_ignore_spaces:n}
@@ -257,35 +268,35 @@
 %   \end{syntax}
 %   Converts the \meta{token list} to a \meta{string}, and leaves in the
 %   input stream the character in position \meta{integer expression} of
-%   the \meta{string}.  In the case of \cs{str_item:Nn} and
-%   \cs{str_item:nn}, all characters including spaces are taken into
-%   account.  The \cs{str_item_ignore_spaces:nn} function skips spaces
-%   in its argument.  If the \meta{integer expression} is negative,
+%   the \meta{string}, starting at $1$ for the first (left-most)
+%   character.  In the case of \cs{str_item:Nn} and \cs{str_item:nn},
+%   all characters including spaces are taken into account.  The
+%   \cs{str_item_ignore_spaces:nn} function skips spaces when counting
+%   characters.  If the \meta{integer expression} is negative,
 %   characters are counted from the end of the \meta{string}. Hence,
-%   $-1$ is the right-most character, \emph{etc.}, while $1$ is the
-%   first (left-most) character.
+%   $-1$ is the right-most character, \emph{etc.}
 % \end{function}
 %
 % \begin{function}[EXP]
-%   {\str_substr:Nnn, \str_substr:nnn, \str_substr_ignore_spaces:nnn}
+%   {\str_range:Nnn, \str_range:nnn, \str_range_ignore_spaces:nnn}
 %   \begin{syntax}
-%     \cs{str_substr:nnn} \Arg{token list} \Arg{start index} \Arg{end index}
+%     \cs{str_range:nnn} \Arg{token list} \Arg{start index} \Arg{end index}
 %   \end{syntax}
 %   Converts the \meta{token list} to a \meta{string}, and leaves in the
-%   input stream the characters from the \meta{start index} inclusive to
-%   the \meta{end index} exclusive. Note that the token count of the
-%   substring is equal to the difference between the two \meta{indices}.
-%   If either of \meta{start index} or \meta{end index} is negative,
-%   then it is incremented by the token count of the list.  If either of
-%   \meta{start index} or \meta{end index} is empty, it is replaced by
-%   the corresponding end-point of the string.  Both \meta{start index}
-%   and \meta{end index} count from $1$ for the first (left most)
-%   character.  For instance,
+%   input stream the characters from the \meta{start index} to the
+%   \meta{end index} inclusive.  Positive \meta{indices} are counted
+%   from the start of the string, $1$~being the first character, and
+%   negative \meta{indices} are counted from the end of the string,
+%   $-1$~being the last character.  If either of \meta{start index} or
+%   \meta{end index} is~$0$, the result is empty.  For instance,
 %   \begin{verbatim}
-%     \iow_term:x { \str_substr:nnn { abcdef } { 2 } { 5 } }
-%     \iow_term:x { \str_substr:nnn { abcdef } { -4 } { } }
+%     \iow_term:x { \str_range:nnn { abcdef } { 2 } { 5 } }
+%     \iow_term:x { \str_range:nnn { abcdef } { -4 } { -1 } }
+%     \iow_term:x { \str_range:nnn { abcdef } { -2 } { -1 } }
+%     \iow_term:x { \str_range:nnn { abcdef } { 0 } { -1 } }
 %   \end{verbatim}
-%   will print \texttt{bcd} and \texttt{cdef} to the terminal.
+%   will print \texttt{bcd}, \texttt{cdef}, \texttt{ef}, and an empty
+%   line to the terminal.
 % \end{function}
 %
 % \section{String conditionals}
@@ -299,9 +310,10 @@
 %     \cs{str_if_eq_p:nn} \Arg{tl_1} \Arg{tl_2}
 %     \cs{str_if_eq:nnTF} \Arg{tl_1} \Arg{tl_2} \Arg{true code} \Arg{false code}
 %   \end{syntax}
-%   Compares the two \meta{token lists} on a character by character
-%   basis, and is \texttt{true} if the two lists contain the same
-%   characters in the same order. Thus for example
+%   Compares the string representations of the two \meta{token lists} on
+%   a character by character basis, and is \texttt{true} if the two
+%   lists contain the same characters in the same order. Thus for
+%   example
 %   \begin{verbatim}
 %     \str_if_eq_p:no { abc } { \tl_to_str:n { abc } }
 %   \end{verbatim}
@@ -387,211 +399,63 @@
 %   code and so should only be used for short-term storage.
 % \end{variable}
 %
-% \section{Encoding functions}
-%
-% Traditionally, string encodings only specify how strings of characters
-% should be stored as bytes. However, the resulting lists of bytes are
-% often to be used in contexts where only a restricted subset of bytes
-% are permitted (\emph{e.g.}, \textsc{pdf} string objects,
-% \textsc{url}s).  Hence, storing a string of characters is done in two
-% steps.
-% \begin{itemize}
-%   \item The code points (\enquote{character codes}) are expressed as
-%     bytes following a given \enquote{encoding}. This can be
-%     \textsc{utf-16}, \textsc{iso 8859-1}, \emph{etc.}  See
-%     Table~\ref{tab:encodings} for a list of supported
-%     encodings.\footnote{Encodings and escapings will be added as they
-%       are requested.}
-%   \item Bytes are translated to \TeX{} tokens through a given
-%     \enquote{escaping}. Those are defined for the most part by the
-%     \texttt{pdf} file format.  See Table~\ref{tab:escapings} for a
-%     list of escaping methods supported.\footnotemark
-% \end{itemize}
-%
-% \begin{table}\centering
-%   \caption{\label{tab:encodings}Supported encodings.
-%     Non-alphanumeric characters are ignored,
-%     and capital letters are lower-cased
-%     before searching for the encoding in this list.}
-%   \begin{tabular}{cc}
-%     \toprule
-%     \meta{Encoding}   & description \\
-%     \midrule
-%     \texttt{utf8}     & \textsc{utf-8} \\
-%     \texttt{utf16}    & \textsc{utf-16}, with byte-order mark \\
-%     \texttt{utf16be}  & \textsc{utf-16}, big-endian \\
-%     \texttt{utf16le}  & \textsc{utf-16}, little-endian \\
-%     \texttt{utf32}    & \textsc{utf-32}, with byte-order mark \\
-%     \texttt{utf32be}  & \textsc{utf-32}, big-endian \\
-%     \texttt{utf32le}  & \textsc{utf-32}, little-endian \\
-%     \texttt{iso88591},  \texttt{latin1}  & \textsc{iso 8859-1} \\
-%     \texttt{iso88592},  \texttt{latin2}  & \textsc{iso 8859-2} \\
-%     \texttt{iso88593},  \texttt{latin3}  & \textsc{iso 8859-3} \\
-%     \texttt{iso88594},  \texttt{latin4}  & \textsc{iso 8859-4} \\
-%     \texttt{iso88595}                    & \textsc{iso 8859-5} \\
-%     \texttt{iso88596}                    & \textsc{iso 8859-6} \\
-%     \texttt{iso88597}                    & \textsc{iso 8859-7} \\
-%     \texttt{iso88598}                    & \textsc{iso 8859-8} \\
-%     \texttt{iso88599},  \texttt{latin5}  & \textsc{iso 8859-9} \\
-%     \texttt{iso885910}, \texttt{latin6}  & \textsc{iso 8859-10} \\
-%     \texttt{iso885911}                   & \textsc{iso 8859-11} \\
-%     \texttt{iso885913}, \texttt{latin7}  & \textsc{iso 8859-13} \\
-%     \texttt{iso885914}, \texttt{latin8}  & \textsc{iso 8859-14} \\
-%     \texttt{iso885915}, \texttt{latin9}  & \textsc{iso 8859-15} \\
-%     \texttt{iso885916}, \texttt{latin10} & \textsc{iso 8859-16} \\
-%     \midrule
-%     Empty & Native (Unicode) string. \\
-%     \bottomrule
-%   \end{tabular}
-% \end{table}
-%
-% \begin{table}\centering
-%   \caption{\label{tab:escapings}Supported escapings.
-%     Non-alphanumeric characters are ignored,
-%     and capital letters are lower-cased
-%     before searching for the escaping in this list.}
-%   \begin{tabular}{cc}
-%     \toprule
-%     \meta{Escaping} & description \\
-%     \midrule
-%     \texttt{bytes}, or empty
-%       & arbitrary bytes \\
-%     \texttt{hex}, \texttt{hexadecimal}
-%       & byte $=$ two hexadecimal digits \\
-%     \texttt{name}
-%       & see \tn{pdfescapename} \\
-%     \texttt{string}
-%       & see \tn{pdfescapestring} \\
-%     \texttt{url}
-%       & encoding used in \textsc{url}s \\
-%     \bottomrule
-%   \end{tabular}
-% \end{table}
-%
-% \begin{function}{\str_set_convert:Nnnn,\str_gset_convert:Nnnn}
-%   \begin{syntax}
-%     \cs{str_set_convert:Nnnn} \meta{str~var} \Arg{string} \Arg{name~1} \Arg{name~2}
-%   \end{syntax}
-%   This function converts the \meta{string} from the encoding given by
-%   \meta{name~1} to the encoding given by \meta{name~2}, and stores the
-%   result in the \meta{str~var}.  Each \meta{name} can have the form
-%   \meta{encoding} or \meta{encoding}\texttt{/}\meta{escaping}, where
-%   the possible values of \meta{encoding} and \meta{escaping} are given
-%   in Tables~\ref{tab:encodings} and~\ref{tab:escapings}, respectively.
-%   The default escaping is to input and output bytes directly.  The
-%   special case of an empty \meta{name} indicates the use of
-%   \enquote{native} strings, 8-bit for pdf\TeX{}, and Unicode strings
-%   for the other two engines.
-%
-%   For example,
-%   \begin{verbatim}
-%     \str_set_convert:Nnnn \l_foo_str { Hello! } { } { utf16/hex }
-%   \end{verbatim}
-%   results in the variable \cs{l_foo_str} holding the string
-%   \texttt{FEFF00480065006C006C006F0021}. This is obtained by
-%   converting each character in the (native) string \texttt{Hello!}  to
-%   the \textsc{utf-16} encoding, and expressing each byte as a pair of
-%   hexadecimal digits. Note the presence of a (big-endian) byte order
-%   mark \hexnum{FEFF}, which can be avoided by specifying the encoding
-%   \texttt{utf16be/hex}.
-%
-%   An error is raised if the \meta{string} is not valid according to
-%   the \meta{escaping~1} and \meta{encoding~1}, or if it cannot be
-%   reencoded in the \meta{encoding~2} and \meta{escaping~2} (for
-%   instance, if a character does not exist in the \meta{encoding~2}).
-%   Erroneous input is replaced by the Unicode replacement character
-%   \hexnum{FFFD}, and characters which cannot be reencoded are replaced
-%   by either the replacement character \hexnum{FFFD} if it exists in
-%   the \meta{encoding~2}, or an encoding-specific replacement
-%   character, or the question mark character.
-% \end{function}
-%
-% \begin{function}[TF]{\str_set_convert:Nnnn,\str_gset_convert:Nnnn}
-%   \begin{syntax}
-%     \cs{str_set_convert:NnnnTF} \meta{str~var} \Arg{string} \Arg{name~1} \Arg{name~2} \Arg{true code} \Arg{false code}
-%   \end{syntax}
-%   As \cs{str_set_convert:Nnnn}, converts the \meta{string} from the
-%   encoding given by \meta{name~1} to the encoding given by
-%   \meta{name~2}, and assigns the result to \meta{str~var}. Contrarily
-%   to \cs{str_set_convert:Nnnn}, the conditional variant does not raise
-%   errors in case the \meta{string} is not valid according to the
-%   \meta{name~1} encoding, or cannot be expressed in the \meta{name~2}
-%   encoding. Instead, the \meta{false code} is performed.
-% \end{function}
-%
-% \section{Internal string functions}
+% \section{Internal \pkg{l3str} functions}
 %
-% \begin{function}{\__str_gset_other:Nn}
+% \begin{function}[EXP]{\__str_to_other:n}
 %   \begin{syntax}
-%     \cs{__str_gset_other:Nn} \meta{tl~var} \Arg{token list}
+%     \cs{__str_to_other:n} \Arg{token list}
 %   \end{syntax}
-%   Converts the \meta{token list} to an \meta{other string}, where
-%   spaces have category code \enquote{other}, and assigns the result to
-%   the \meta{tl~var}, globally.
+%   Converts the \meta{token list} to a \meta{other string}, where
+%   spaces have category code \enquote{other}.  This function can be
+%   \texttt{f}-expanded without fear of losing a leading space, since
+%   spaces do not have category code $10$ in its result.  It takes a
+%   time quadratic in the character count of the string, but there exist
+%   non-expandable ways to reach linear time.
 % \end{function}
 %
-% \begin{function}{\__str_hexadecimal_use:NTF}
+% \begin{function}[EXP]{\__str_count_unsafe:n}
 %   \begin{syntax}
-%     \cs{__str_hexadecimal_use:NTF} \meta{token} \Arg{true code} \Arg{false code}
+%     \cs{__str_count_unsafe:n} \Arg{other string}
 %   \end{syntax}
-%   If the \meta{token} is a hexadecimal digit (upper case or lower
-%   case), its upper-case version is left in the input stream,
-%   \emph{followed} by the \meta{true code}. Otherwise, the \meta{false
-%     code} is left in the input stream.
-%   \begin{texnote}
-%     This function fails on some inputs if the escape character is a
-%     hexadecimal digit.  We are thus careful to set the escape
-%     character to a known (safe) value before using it.
-%   \end{texnote}
+%   This function expects an argument that is entirely made of
+%   characters with category \enquote{other}, as produced by
+%   \cs{__str_to_other:n}.  It leaves in the input stream the number of
+%   character tokens in the \meta{other string}, faster than the
+%   analoguous \cs{str_count:n} function.
 % \end{function}
 %
-% \begin{function}[EXP]{\__str_output_byte:n}
+% \begin{function}[EXP]{\__str_range_unsafe:nnn}
 %   \begin{syntax}
-%     \cs{__str_output_byte:n} \Arg{intexpr}
+%     \cs{__str_range_unsafe:nnn} \Arg{other string} \Arg{start index} \Arg{end index}
 %   \end{syntax}
-%   Expands to a character token with category other and character code
-%   equal to the value of \meta{intexpr}.  The value of \meta{intexpr}
-%   must be in the range $[-1, 255]$, and any value outside this range
-%   results in undefined behaviour.  The special value $-1$ is used to
-%   produce an empty result.
+%   Identical to \cs{str_range:nnn} except that the first argument is
+%   expected to be entirely made of characters with category
+%   \enquote{other}, as produced by \cs{__str_to_other:n}, and the
+%   result is also an \meta{other string}.
 % \end{function}
 %
-% \section{Possibilities, and things to do}
+% \section{Possible additions to \pkg{l3str}}
 %
-% Encoding/escaping-related tasks.
+% Semantically correct copies of some \texttt{tl} functions.
 % \begin{itemize}
-%   \item Describe the internal format in the code comments. Refuse code
-%     points in $[\hexnum{D800}, \hexnum{DFFF}]$ in the internal
-%     representation?
-%   \item Add documentation about each encoding and escaping method, and
-%     add examples.
-%   \item The \texttt{hex} unescaping should raise an error for
-%     odd-token count strings.
-%   \item Decide what bytes should be escaped in the \texttt{url}
-%     escaping. Perhaps |!'()*-./0123456789_| are safe, and all other
-%     characters should be escaped?
-%   \item Automate generation of 8-bit mapping files.
-%   \item Change the framework for 8-bit encodings: for decoding from
-%     8-bit to Unicode, use $256$ integer registers; for encoding, use a
-%     tree-box.
-%   \item More encodings (see Heiko's \pkg{stringenc}). CESU?
-%   \item More escapings: shell escapes, lua escapes, etc?
+%   \item \cs{c_space_str}
+%   \item \cs{str_clear:N}, \cs{str_gclear:N}, \cs{str_clear_new:N},
+%     \cs{str_gclear_new:N}.
+%   \item \cs{str_concat:NNN}, \cs{str_gconcat:NNN}
+%   \item \cs{str_set_eq:NN}, \cs{str_gset_eq:NN}
+%   \item \cs{str_if_empty:NTF}, \cs{str_if_empty_p:N}
+%   \item \cs{str_if_exist:NTF}, \cs{str_if_exist_p:N}
+%   \item \cs{str_use:N}
 % \end{itemize}
 %
-% Other string tasks.
+% Some functions that are not copies of \texttt{tl} functions.
 % \begin{itemize}
+%   \item \cs{str_if_blank:NTF}, \cs{str_if_blank_p:N}.
+%   \item \cs{str_map_inline:Nn}, \cs{str_map_function:NN},
+%     \cs{str_map_variable:NNn}, and \texttt{:n} analogs.
 %   \item Expandable \cs{str_if_in:nnTF}?
-%   \item \cs{str_if_head_eq:nN}
+%   \item \cs{str_if_head_eq:nNTF}, \cs{str_if_head_eq_p:nN}
 %   \item \cs{str_if_numeric/decimal/integer:n}, perhaps in \pkg{l3fp}?
-%   \item Should \cs{str_item:Nn} be \cs{str_char:Nn}?
-%   \item Should \cs{str_substr:Nnn} be \cs{str_range:Nnn}?
-%   \item Introduce \cs{str_slice:Nnnn} with a third \enquote{step}
-%     argument?  Or should we simply have \cs{str_slice:Nn}
-%     \meta{string} \Arg{clist}, where the \meta{clist}'s items are
-%     either one integer expression, two integer expressions separated
-%     by |:|, or three integer expressions separated by |:|, \emph{cf.}
-%     Python's extended slice syntax?
-%   \item Analog of \texttt{printf}?
 % \end{itemize}
 %
 % \end{documentation}
@@ -611,7 +475,6 @@
 %    \begin{macrocode}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
-\RequirePackage{l3tl-analysis,l3tl-build,l3flag}
 %    \end{macrocode}
 %
 % The following string-related functions are currently defined in
@@ -623,23 +486,11 @@
 %   \item \cs{token_to_str:N}, \cs{cs_to_str:N}
 %   \item \cs{str_head:n}, \cs{__str_head:w}, (copied here)
 %   \item \cs{str_tail:n}, \cs{__str_tail:w}, (copied here)
-%   \item \cs{str_count_ignore_spaces} (unchanged)
-%   \item \cs{str_count_loop:NNNNNNNNN} (unchanged)
+%   \item \cs{__str_count_ignore_spaces} (unchanged)
+%   \item \cs{__str_count_loop:NNNNNNNNN} (unchanged)
 % \end{itemize}
 %
-% \subsection{Helpers}
-%
-% \subsubsection{A function unrelated to strings}
-%
-% \begin{macro}[EXP,aux]{\use_ii_i:nn}
-%   A function used to swap its arguments.
-%    \begin{macrocode}
-\cs_if_exist:NF \use_ii_i:nn
-  { \cs_new:Npn \use_ii_i:nn #1#2 { #2 #1 } }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsubsection{Assigning strings}
+% \subsection{String assignments}
 %
 % \begin{macro}{\str_new:N, \str_new:c}
 %   A string is simply a token list.
@@ -686,73 +537,13 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \subsubsection{Variables and constants}
-%
-% \begin{macro}{\@@_tmp:w}
-% \begin{variable}{\l_@@_internal_int}
-% \begin{variable}{\l_@@_internal_tl}
-%   Internal scratch space for some functions.
-%    \begin{macrocode}
-\cs_new_protected_nopar:Npn \@@_tmp:w { }
-\tl_new:N \l_@@_internal_tl
-\int_new:N \l_@@_internal_int
-%    \end{macrocode}
-% \end{variable}
-% \end{variable}
-% \end{macro}
-%
-% \begin{variable}{\g_@@_result_tl}
-%   The \cs{g_@@_result_tl} variable is used to hold the result of
-%   various internal string operations (mostly conversions) which are
-%   typically performed in a group. The variable is global so that it
-%   remains defined outside the group, to be assigned to a user-provided
-%   variable.
-%    \begin{macrocode}
-\tl_new:N \g_@@_result_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}
-%   {
-%     \c_forty_eight, \c_fifty_eight, \c_sixty_five, \c_ninety_one,
-%     \c_ninety_seven, \c_one_hundred_twenty_three,
-%     \c_one_hundred_twenty_seven
-%   }
-%   We declare here some integer values which delimit ranges of ASCII
-%   characters of various types. This is mostly used in \pkg{l3regex}.
-%    \begin{macrocode}
-\int_const:Nn \c_forty_eight  { 48 }
-\int_const:Nn \c_fifty_eight  { 58 }
-\int_const:Nn \c_sixty_five   { 65 }
-\int_const:Nn \c_ninety_one   { 91 }
-\int_const:Nn \c_ninety_seven { 97 }
-\int_const:Nn \c_one_hundred_twenty_three { 123 }
-\int_const:Nn \c_one_hundred_twenty_seven { 127 }
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\c_max_char_int}
-%   The maximum valid character code is $255$ for pdf\TeX{}, and
-%   $1114111$ for other engines.
-%    \begin{macrocode}
-\int_const:Nn \c_max_char_int
-  { \pdftex_if_engine:TF { "FF } { "10FFFF } }
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\c_@@_replacement_char_int}
-%   When converting, invalid bytes are replaced by the Unicode
-%   replacement character \hexnum{FFFD}.
-%    \begin{macrocode}
-\int_const:Nn \c_@@_replacement_char_int { "FFFD }
-%    \end{macrocode}
-% \end{variable}
+% \subsection{String variables and constants}
 %
 % \begin{variable}
 %   {
 %     \c_backslash_str,
-%     \c_lbrace_str,
-%     \c_rbrace_str,
+%     \c_left_brace_str,
+%     \c_right_brace_str,
 %     \c_hash_str,
 %     \c_tilde_str,
 %     \c_percent_str
@@ -760,153 +551,36 @@
 %   For all of those strings, use \cs{cs_to_str:N} to get characters with
 %   the correct category code.
 %    \begin{macrocode}
-\tl_const:Nx \c_backslash_str { \cs_to_str:N \\ }
-\tl_const:Nx \c_lbrace_str    { \cs_to_str:N \{ }
-\tl_const:Nx \c_rbrace_str    { \cs_to_str:N \} }
-\tl_const:Nx \c_hash_str      { \cs_to_str:N \# }
-\tl_const:Nx \c_tilde_str     { \cs_to_str:N \~ }
-\tl_const:Nx \c_percent_str   { \cs_to_str:N \% }
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\g_@@_alias_prop}
-%   To avoid needing one file per encoding/escaping alias, we keep track
-%   of those in a property list.
-%    \begin{macrocode}
-\prop_new:N \g_@@_alias_prop
-\prop_gput:Nnn \g_@@_alias_prop { latin1 } { iso88591 }
-\prop_gput:Nnn \g_@@_alias_prop { latin2 } { iso88592 }
-\prop_gput:Nnn \g_@@_alias_prop { latin3 } { iso88593 }
-\prop_gput:Nnn \g_@@_alias_prop { latin4 } { iso88594 }
-\prop_gput:Nnn \g_@@_alias_prop { latin5 } { iso88599 }
-\prop_gput:Nnn \g_@@_alias_prop { latin6 } { iso885910 }
-\prop_gput:Nnn \g_@@_alias_prop { latin7 } { iso885913 }
-\prop_gput:Nnn \g_@@_alias_prop { latin8 } { iso885914 }
-\prop_gput:Nnn \g_@@_alias_prop { latin9 } { iso885915 }
-\prop_gput:Nnn \g_@@_alias_prop { latin10 } { iso885916 }
-\prop_gput:Nnn \g_@@_alias_prop { utf16le } { utf16 }
-\prop_gput:Nnn \g_@@_alias_prop { utf16be } { utf16 }
-\prop_gput:Nnn \g_@@_alias_prop { utf32le } { utf32 }
-\prop_gput:Nnn \g_@@_alias_prop { utf32be } { utf32 }
-\prop_gput:Nnn \g_@@_alias_prop { hexadecimal } { hex }
+\str_const:Nx \c_backslash_str { \cs_to_str:N \\ }
+\str_const:Nx \c_left_brace_str  { \cs_to_str:N \{ }
+\str_const:Nx \c_right_brace_str { \cs_to_str:N \} }
+\str_const:Nx \c_hash_str      { \cs_to_str:N \# }
+\str_const:Nx \c_tilde_str     { \cs_to_str:N \~ }
+\str_const:Nx \c_percent_str   { \cs_to_str:N \% }
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{\g_@@_error_bool}
-%   In conversion functions with a built-in conditional, errors are not
-%   reported directly to the user, but the information is collected in
-%   this boolean, used at the end to decide on which branch of the
-%   conditional to take.
+% \begin{variable}{\l_tmpa_str, \l_tmpb_str, \g_tmpa_str, \g_tmpb_str}
+%   Scratch strings.
 %    \begin{macrocode}
-\bool_new:N \g_@@_error_bool
+\str_new:N \l_tmpa_str
+\str_new:N \l_tmpb_str
+\str_new:N \g_tmpa_str
+\str_new:N \g_tmpb_str
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{str_byte, str_error}
-%   Conversions from one \meta{encoding}/\meta{escaping} pair to another
-%   are done within \texttt{x}-expanding assignments. Errors are
-%   signalled by raising the relevant flag.
-%    \begin{macrocode}
-\flag_new:n { str_byte }
-\flag_new:n { str_error }
-%    \end{macrocode}
-% \end{variable}
-%
-% \subsubsection{Escaping spaces}
+% \subsection{Counting characters}
 %
-% \begin{macro}[EXP]{\@@_to_other:n}
-% \begin{macro}[EXP, aux]{\@@_to_other_loop:w, \@@_to_other_end:w}
-%   \begin{syntax}
-%     \cs{@@_to_other:n} \Arg{token list}
-%   \end{syntax}
-%   Converts the \meta{token list} to a \meta{other string}, where
-%   spaces have category code \enquote{other}.  First apply
-%   \cs{tl_to_str:n}, then replace all spaces by \enquote{other} spaces,
-%   $8$ at a time, storing the converted part of the string between the
-%   \cs{q_mark} and \cs{q_stop} markers.  This function can be
-%   \texttt{f}-expanded without fear of losing a leading space, since
-%   spaces do not have category code $10$ in its result.  This function
-%   takes a time quadratic in the token count of the string;
-%   \cs{@@_gset_other:Nn} is faster but not expandable.
+% \begin{macro}[EXP]{\str_count_spaces:N, \str_count_spaces:n}
+% \begin{macro}[EXP, aux]{\@@_count_spaces_loop:wwwwwwwww}
+%   To speed up this function, we grab and discard $9$ space-delimited
+%   arguments in each iteration of the loop.  The loop stops when the
+%   last argument is one of the trailing |X|\meta{number}, and that
+%   \meta{number} is added to the sum of $9$ that preceeds, to adjust
+%   the result.
 %    \begin{macrocode}
-\group_begin:
-\char_set_lccode:nn { `\* } { `\  }
-\char_set_lccode:nn { `\A } { `\A }
-\tl_to_lowercase:n
-  {
-    \group_end:
-    \cs_new:Npn \@@_to_other:n #1
-      {
-        \exp_after:wN \@@_to_other_loop:w \tl_to_str:n {#1} ~ %
-        A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_mark \q_stop
-      }
-    \cs_new:Npn \@@_to_other_loop:w
-      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 \q_stop
-      {
-        \if_meaning:w A #8
-          \@@_to_other_end:w
-        \fi:
-        \@@_to_other_loop:w
-        #9 #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * \q_stop
-      }
-    \cs_new:Npn \@@_to_other_end:w \fi: #1 \q_mark #2 * A #3 \q_stop
-      { \fi: #2 }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_gset_other:Nn}
-% \begin{macro}[aux,EXP]{\@@_gset_other_loop:w}
-% \begin{macro}[aux,EXP]{\@@_gset_other_end:w}
-%   This function could be done by using \cs{@@_to_other:n} within
-%   an \texttt{x}-expansion, but that would take a time quadratic in the
-%   size of the string. Instead, we can \enquote{leave the result behind
-%     us} in the input stream, to be captured into the expanding
-%   assignment. This gives us a linear time.
-%    \begin{macrocode}
-\group_begin:
-\char_set_lccode:nn { `\* } { `\  }
-\char_set_lccode:nn { `\A } { `\A }
-\tl_to_lowercase:n
-  {
-    \group_end:
-    \cs_new_protected:Npn \@@_gset_other:Nn #1#2
-      {
-        \tl_gset:Nx #1
-          {
-            \exp_after:wN \@@_gset_other_loop:w \tl_to_str:n {#2} ~ %
-            A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_stop
-          }
-      }
-    \cs_new:Npn \@@_gset_other_loop:w
-      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 ~
-      {
-        \if_meaning:w A #9
-          \@@_gset_other_end:w
-        \fi:
-        #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * #9
-        \@@_gset_other_loop:w *
-      }
-    \cs_new:Npn \@@_gset_other_end:w \fi: #1 * A #2 \q_stop
-      { \fi: #1 }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Characters given by their position}
-%
-% \begin{macro}[EXP]{\str_count_spaces:N}
-% \begin{macro}[EXP]{\str_count_spaces:n}
-% \begin{macro}[EXP,aux]{\@@_count_spaces_loop:wwwwwwwww}
-%   To speed up this function, we grab $9$ spaces in each step.  The
-%   loop stops when the last argument is one of the trailing
-%   |X|\meta{number}, and that \meta{number} is added to the sum of $9$
-%   that preceeds, to adjust the result.
-%    \begin{macrocode}
-\cs_new:Npn \str_count_spaces:N
+\cs_new_nopar:Npn \str_count_spaces:N
   { \exp_args:No \str_count_spaces:n }
 \cs_new:Npn \str_count_spaces:n #1
   {
@@ -921,30 +595,29 @@
 \cs_new:Npn \@@_count_spaces_loop:wwwwwwwww #1~#2~#3~#4~#5~#6~#7~#8~#9~
   {
     \if_meaning:w X #9
-      \exp_after:wN \use_none_delimit_by_q_stop:w
+      \use_i_delimit_by_q_stop:nw
     \fi:
     \c_nine + \@@_count_spaces_loop:wwwwwwwww
   }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
-% \begin{macro}[EXP]{\str_count:N}
-% \begin{macro}[EXP]{\str_count:n}
-% \begin{macro}[EXP]{\@@_count_unsafe:n}
-% \begin{macro}[EXP]{\str_count_ignore_spaces:n}
-% \begin{macro}[EXP,aux]{\@@_count:n, \@@_count_loop:NNNNNNNNN}
-%   To measure the token count of a string we could first escape all spaces
-%   using \cs{@@_to_other:o}, then measure the count of this token
-%   list. However, this would be quadratic in the length of the string,
-%   and we can do better. Namely, add the number of spaces (counted
-%   using the functions defined above) to the length ignoring spaces.
-%   To measure the length ignoring spaces we use the same technique as
-%   for counting spaces: loop, grabbing $9$ characters at each step, and
-%   end as soon as we reach one of the $9$ trailing items.  The
-%   \texttt{_unsafe} variant expects a token list consisting entirely of
-%   category code $12$ characters.
+% \begin{macro}[EXP]{\str_count:N, \str_count:n, \str_count_ignore_spaces:n}
+% \begin{macro}[EXP, int]{\@@_count_unsafe:n}
+% \begin{macro}[EXP, aux]{\@@_count:n, \@@_count_loop:NNNNNNNNN}
+%   To count characters in a string we could first escape all spaces
+%   using \cs{@@_to_other:n}, then pass the result to \cs{tl_count:n}.
+%   However, the escaping step would be quadratic in the number of
+%   characters in the string, and we can do better.  Namely, sum the
+%   number of spaces (\cs{str_count_spaces:n}) and the result of
+%   \cs{tl_count:n}, which ignores spaces.  Since strings tend to be
+%   longer than token lists, we use specialized functions to count
+%   characters ignoring spaces.  Namely, loop, grabbing $9$ non-space
+%   characters at each step, and end as soon as we reach one of the $9$
+%   trailing items.  The \texttt{_unsafe} variant expects a token list
+%   already converted to category code $12$ characters, and is used by
+%   \cs{str_item:nn} and \cs{str_range:nnn}.
 %    \begin{macrocode}
 \cs_new_nopar:Npn \str_count:N { \exp_args:No \str_count:n }
 \cs_new:Npn \str_count:n #1
@@ -987,22 +660,20 @@
 % \end{macro}
 % \end{macro}
 % \end{macro}
-% \end{macro}
-% \end{macro}
 %
-% \begin{macro}[EXP]{\str_head:N}
-% \begin{macro}[EXP]{\str_head:n}
-% \begin{macro}[EXP]{\str_head_ignore_spaces:n}
-% \begin{macro}[EXP,aux]{\@@_head:w}
+% \subsection{Head and tail of a string}
+%
+% \begin{macro}[EXP]{\str_head:N, \str_head:n, \str_head_ignore_spaces:n}
+% \begin{macro}[EXP, aux]{\@@_head:w}
 %   The \texttt{_ignore_spaces} variant is almost identical to
 %   \cs{tl_head:n}.  As usual, \cs{str_head:N} expands its argument and
-%   hands it to \cs{str_head:n}. To circumvent the fact that \TeX{}
+%   hands it to \cs{str_head:n}.  To circumvent the fact that \TeX{}
 %   skips spaces when grabbing undelimited macro parameters,
 %   \cs{@@_head:w} takes an argument delimited by a space. If |#1|
 %   starts with a non-space character, \cs{use_i_delimit_by_q_stop:nw}
 %   leaves that in the input stream. On the other hand, if |#1| starts
-%   with a space, the \cs{@@_head:w} takes an empty argument, and
-%   the single (braced) space in the definition of \cs{@@_head:w}
+%   with a space, the \cs{@@_head:w} takes an empty argument, and the
+%   single (initially braced) space in the definition of \cs{@@_head:w}
 %   makes its way to the output. Finally, for an empty argument, the
 %   (braced) empty brace group in the definition of \cs{str_head:n}
 %   gives an empty result after passing through
@@ -1025,23 +696,23 @@
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
-% \end{macro}
 %
-% \begin{macro}[EXP]{\str_tail:N}
-% \begin{macro}[EXP]{\str_tail:n}
-% \begin{macro}[EXP]{\str_tail_ignore_spaces:n}
-% \begin{macro}[EXP,aux]{\@@_tail_auxi:w}
-% \begin{macro}[EXP,aux]{\@@_tail_auxii:w}
-%   As when fetching the head of a string, the \texttt{_ignore_spaces}
-%   variant is similar to \cs{tl_tail:n}.  The more commonly used
-%   \cs{str_tail:n} function is a little bit more convoluted: hitting
-%   the front of the string with \cs{reverse_if:N} \cs{if_charcode:w}
-%   \cs{scan_stop:} removes the first character (which necessarily makes
-%   the test true, since it cannot match \cs{scan_stop:}). The auxiliary
-%   function inserts the required \cs{fi:} to close the conditional, and
-%   leaves the tail of the string in the input string. The details are
-%   such that an empty string has an empty tail.
+% \begin{macro}[EXP]{\str_tail:N, \str_tail:n, \str_tail_ignore_spaces:n}
+% \begin{macro}[EXP, aux]{\@@_tail_auxi:w, \@@_tail_auxii:w}
+%   Getting the tail is a little bit more convoluted than the head of a
+%   string.  We hit the front of the string with \cs{reverse_if:N}
+%   \cs{if_charcode:w} \cs{scan_stop:}.  This removes the first
+%   character, and necessarily makes the test true, since the character
+%   cannot match \cs{scan_stop:}. The auxiliary function then inserts
+%   the required \cs{fi:} to close the conditional, and leaves the tail
+%   of the string in the input stream.  The details are such that an
+%   empty string has an empty tail (this requires in particular that the
+%   end-marker |X| be unexpandable and not a control sequence).  The
+%   \texttt{_ignore_spaces} is rather simpler: after converting the
+%   input to a string, \cs{@@_tail_auxii:w} removes one undelimited
+%   argument and leaves everything else until an end-marker \cs{q_mark}.
+%   One can check that an empty (or blank) string yields an empty
+%   tail.
 %    \begin{macrocode}
 \cs_new_nopar:Npn \str_tail:N { \exp_args:No \str_tail:n }
 \cs_set:Npn \str_tail:n #1
@@ -1054,26 +725,63 @@
 \cs_new:Npn \str_tail_ignore_spaces:n #1
   {
     \exp_after:wN \@@_tail_auxii:w
-    \tl_to_str:n {#1} X X \q_stop
+    \tl_to_str:n {#1} \q_mark \q_mark \q_stop
   }
-\cs_new:Npn \@@_tail_auxii:w #1 #2 X #3 \q_stop { #2 }
+\cs_new:Npn \@@_tail_auxii:w #1 #2 \q_mark #3 \q_stop { #2 }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
+%
+% \subsection{Accessing specific characters in a string}
+%
+% \begin{macro}[EXP, int]{\@@_to_other:n}
+% \begin{macro}[EXP, aux]{\@@_to_other_loop:w, \@@_to_other_end:w}
+%   First apply \cs{tl_to_str:n}, then replace all spaces by
+%   \enquote{other} spaces, $8$ at a time, storing the converted part of
+%   the string between the \cs{q_mark} and \cs{q_stop} markers.  The end
+%   is detected when \cs{@@_to_other_loop:w} finds one of the trailing
+%   |A|, distinguished from any contents of the initial token list by
+%   their category.  Then \cs{@@_to_other_end:w} is called, and finds
+%   the result between \cs{q_mark} and the first |A| (well, there is
+%   also the need to remove a space).
+%    \begin{macrocode}
+\group_begin:
+\char_set_lccode:nn { `\* } { `\  }
+\char_set_lccode:nn { `\A } { `\A }
+\tl_to_lowercase:n
+  {
+    \group_end:
+    \cs_new:Npn \@@_to_other:n #1
+      {
+        \exp_after:wN \@@_to_other_loop:w \tl_to_str:n {#1} ~ %
+        A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_mark \q_stop
+      }
+    \cs_new:Npn \@@_to_other_loop:w
+      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 \q_stop
+      {
+        \if_meaning:w A #8
+          \@@_to_other_end:w
+        \fi:
+        \@@_to_other_loop:w
+        #9 #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * \q_stop
+      }
+    \cs_new:Npn \@@_to_other_end:w \fi: #1 \q_mark #2 * A #3 \q_stop
+      { \fi: #2 }
+  }
+%    \end{macrocode}
 % \end{macro}
 % \end{macro}
 %
-% \begin{macro}[EXP, int]{\@@_skip_c_zero:w}
-% \begin{macro}[EXP, aux]{\@@_skip_loop:wNNNNNNNN}
-% \begin{macro}[EXP, aux]{\@@_skip_end:w, \@@_skip_end:NNNNNNNN}
+% \begin{macro}[EXP, aux]{\@@_skip_c_zero:w}
+% \begin{macro}[EXP, aux]
+%   {\@@_skip_loop:wNNNNNNNN, \@@_skip_end:w, \@@_skip_end:NNNNNNNN}
 %   Removes |max(#1,0)| characters from the input stream, and then
-%   leaves \cs{c_zero}. This should be expanded using
+%   leaves \cs{c_zero}.  This should be expanded using
 %   \cs{tex_romannumeral:D}.  We remove characters $8$ at a time until
-%   there are at most $8$ to remove. Then we do a dirty trick: the
+%   there are at most $8$ to remove.  Then we do a dirty trick: the
 %   \cs{if_case:w} construction leaves between $0$ and $8$ times the
 %   \cs{or:} control sequence, and those \cs{or:} become arguments of
-%   \cs{@@_skip_end:NNNNNNNN}. If the number of characters to remove
+%   \cs{@@_skip_end:NNNNNNNN}.  If the number of characters to remove
 %   is $6$, say, then there are two \cs{or:} left, and the $8$ arguments
 %   of \cs{@@_skip_end:NNNNNNNN} are the two \cs{or:}, and $6$
 %   characters from the input stream, exactly what we wanted to
@@ -1083,7 +791,7 @@
 %    \begin{macrocode}
 \cs_new:Npn \@@_skip_c_zero:w #1;
   {
-    \if_int_compare:w \__int_eval:w #1 > \c_eight
+    \if_int_compare:w #1 > \c_eight
       \exp_after:wN \@@_skip_loop:wNNNNNNNN
     \else:
       \exp_after:wN \@@_skip_end:w
@@ -1096,34 +804,31 @@
 \cs_new:Npn \@@_skip_end:w #1 ;
   {
     \exp_after:wN \@@_skip_end:NNNNNNNN
-    \if_case:w \if_int_compare:w #1 > \c_zero #1 \else: 0 \fi: \exp_stop_f:
-    \or: \or: \or: \or: \or: \or: \or: \or:
+    \if_case:w #1 \exp_stop_f: \or: \or: \or: \or: \or: \or: \or: \or:
   }
 \cs_new:Npn \@@_skip_end:NNNNNNNN #1#2#3#4#5#6#7#8 { \fi: \c_zero }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
-% \begin{macro}[EXP,int]{\@@_collect_delimit_by_q_stop:w}
-% \begin{macro}[EXP,aux]{\@@_collect_loop:wn, \@@_collect_loop:wnNNNNNNN}
-% \begin{macro}[EXP,aux]
-%   {\@@_collect_end:wn, \@@_collect_end:nnnnnnnnw} Collects
-%   |max(#1,0)| characters, and removes everything else until
+% \begin{macro}[EXP, aux]{\@@_collect_delimit_by_q_stop:w}
+% \begin{macro}[EXP, aux]
+%   {
+%     \@@_collect_loop:wn, \@@_collect_loop:wnNNNNNNN,
+%     \@@_collect_end:wn, \@@_collect_end:nnnnnnnnw
+%   }
+%   Collects |max(#1,0)| characters, and removes everything else until
 %   \cs{q_stop}. This is somewhat similar to \cs{@@_skip_c_zero:w}, but
-%   this time we can only grab $7$ characters at a time.  At the end, we
-%   use an \cs{if_case:w} trick again, so that the $8$ first arguments
-%   of \cs{@@_collect_end:nnnnnnnnw} are some \cs{or:}, followed by
-%   an \cs{fi:}, followed by |#1| characters from the input
-%   stream. Simply leaving this in the input stream will close the
-%   conditional properly and the \cs{or:} disappear.
+%   accepts integer expression arguments.  This time we can only grab
+%   $7$ characters at a time.  At the end, we use an \cs{if_case:w}
+%   trick again, so that the $8$ first arguments of
+%   \cs{@@_collect_end:nnnnnnnnw} are some \cs{or:}, followed by an
+%   \cs{fi:}, followed by |#1| characters from the input stream. Simply
+%   leaving this in the input stream will close the conditional properly
+%   and the \cs{or:} disappear.
 %    \begin{macrocode}
 \cs_new:Npn \@@_collect_delimit_by_q_stop:w #1;
-  {
-    \exp_after:wN \@@_collect_loop:wn
-    \int_use:N \__int_eval:w #1 ;
-    { }
-  }
+  { \@@_collect_loop:wn #1 ; { } }
 \cs_new:Npn \@@_collect_loop:wn #1 ;
   {
     \if_int_compare:w #1 > \c_seven
@@ -1150,20 +855,25 @@
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
-% \begin{macro}[EXP]{\str_item:Nn}
-% \begin{macro}[EXP]{\str_item:nn}
-% \begin{macro}[EXP]{\str_item_ignore_spaces:nn}
-% \begin{macro}[EXP]{\@@_item_unsafe:nn}
-% \begin{macro}[EXP,aux]{\@@_item:ww}
-%   This is mostly shuffling arguments around to avoid measuring the
-%   length of the string more than once, and make sure that the
-%   parameters given to \cs{@@_skip_c_zero:w} are necessarily within
-%   the bounds of the length of the string.  The \texttt{_ignore_spaces}
-%   function cheats a little bit in that it doesn't hand to
-%   \cs{@@_item_unsafe:nn} an \enquote{other string}. This is alright,
-%   as everything else is done with undelimited arguments.
+% \begin{macro}[EXP]{\str_item:Nn, \str_item:nn, \str_item_ignore_spaces:nn}
+% \begin{macro}[EXP, aux]{\@@_item_unsafe:nn, \@@_item:ww}
+%   The \cs{str_item:nn} hands its argument with spaces escaped to
+%   \cs{@@_item_unsafe:nn}, and makes sure to turn the result back into
+%   a proper string (with category code~$10$ spaces) eventually.  The
+%   \cs{str_item_ignore_spaces:nn} function cheats a little bit in that
+%   it doesn't hand to \cs{@@_item_unsafe:nn} an \enquote{other string}.
+%   This is safe, as everything else is done with undelimited arguments.
+%   Then evaluate the \meta{index} argument~|#2| and count characters in
+%   the string, passing those two numbers to \cs{@@_item:ww} for further
+%   analysis.  If the \meta{index} is negative, shift by |#2|, and
+%   remove that number of characters before returning the next item in
+%   the input stream (and if |#1| is smaller than $-|#2|$, nothing is
+%   returned).  If the \meta{index} is positive, ignore that number
+%   (minus one) of characters before returning the next one.  The shift
+%   by one is obtained by inserting an empty brace group before the
+%   string in that case: that brace group also covers the case where the
+%   \meta{index} is zero.
 %    \begin{macrocode}
 \cs_new_nopar:Npn \str_item:Nn { \exp_args:No \str_item:nn }
 \cs_new:Npn \str_item:nn #1#2
@@ -1181,8 +891,7 @@
     \exp_after:wN \@@_item:ww
     \int_use:N \__int_eval:w #2 \exp_after:wN ;
     \__int_value:w \@@_count_unsafe:n {#1} ;
-      { } #1
-    \q_stop
+    #1 \q_stop
   }
 \cs_new:Npn \@@_item:ww #1; #2;
   {
@@ -1192,7 +901,8 @@
           { \use_none_delimit_by_q_stop:w }
           {
             \exp_after:wN \use_i_delimit_by_q_stop:nw
-            \tex_romannumeral:D \@@_skip_c_zero:w #1 + #2 + \c_one ;
+            \tex_romannumeral:D \exp_after:wN \@@_skip_c_zero:w
+              \int_use:N \__int_eval:w #1 + #2 ;
           }
       }
       {
@@ -1200,99 +910,97 @@
           { \use_none_delimit_by_q_stop:w }
           {
             \exp_after:wN \use_i_delimit_by_q_stop:nw
-            \tex_romannumeral:D \@@_skip_c_zero:w #1 ;
+            \tex_romannumeral:D \@@_skip_c_zero:w #1 ; { }
           }
       }
   }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
-% \end{macro}
+%
+% \begin{macro}[EXP, aux]{\@@_range_normalize:nn}
+%   This function converts an \meta{index} argument into an explicit
+%   position in the string (a result of $0$ denoting \enquote{out of
+%     bounds}).  Expects two explicit integer arguments: the
+%   \meta{index} |#1| and the string count~|#2|.  If |#1| is negative,
+%   replace it by $|#1| + |#2| + 1$, then limit to the range $[0,
+%   |#2|]$.
+%    \begin{macrocode}
+\cs_new:Npn \@@_range_normalize:nn #1#2
+  {
+    \int_eval:n
+      {
+        \if_int_compare:w #1 < \c_zero
+          \if_int_compare:w #1 < -#2 \exp_stop_f:
+            \c_zero
+          \else:
+            #1 + #2 + \c_one
+          \fi:
+        \else:
+          \if_int_compare:w #1 < #2 \exp_stop_f:
+            #1
+          \else:
+            #2
+          \fi:
+        \fi:
+      }
+  }
+%    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[EXP]{\str_substr:Nnn}
-% \begin{macro}[EXP]{\str_substr:nnn}
-% \begin{macro}[EXP]{\str_substr_ignore_spaces:nnn}
-% \begin{macro}[EXP,aux]
-%   {
-%     \@@_substr_unsafe:nnn,
-%     \@@_substr:nN,
-%     \@@_substr:www,
-%     \@@_substr:nnw,
-%     \@@_substr_normalize_range:nn
-%   }
-%   Sanitize the string. Then evaluate the arguments, replacing them by
-%   \cs{c_zero} or \cs{c_max_int} if they are empty.  Then limit the
-%   range to be at most the length of the string (this avoids needing to
-%   check for the end of the string when grabbing characters).
+% \begin{macro}[EXP]
+%   {\str_range:Nnn, \str_range:nnn, \str_range_ignore_spaces:nnn}
+% \begin{macro}[EXP, int]{\@@_range_unsafe:nnn}
+% \begin{macro}[EXP, aux]{\@@_range:www, \@@_range:nnw}
+%   Sanitize the string.  Then evaluate the arguments.  At this stage we
+%   also decrement the \meta{start index}, since our goal is to know how
+%   many characters should be removed.  Then limit the range to be
+%   non-negative and at most the length of the string (this avoids
+%   needing to check for the end of the string when grabbing
+%   characters), shifting negative numbers by the appropriate amount.
 %   Afterwards, skip characters, then keep some more, and finally drop
 %   the end of the string.
 %    \begin{macrocode}
-\cs_new_nopar:Npn \str_substr:Nnn { \exp_args:No \str_substr:nnn }
-\cs_new:Npn \str_substr:nnn #1#2#3
+\cs_new_nopar:Npn \str_range:Nnn { \exp_args:No \str_range:nnn }
+\cs_new:Npn \str_range:nnn #1#2#3
   {
     \exp_args:Nf \tl_to_str:n
       {
-        \exp_args:Nf \@@_substr_unsafe:nnn
+        \exp_args:Nf \@@_range_unsafe:nnn
           { \@@_to_other:n {#1} } {#2} {#3}
       }
   }
-\cs_new:Npn \str_substr_ignore_spaces:nnn #1
-  { \exp_args:No \@@_substr_unsafe:nnn { \tl_to_str:n {#1} } }
-\cs_new:Npn \@@_substr_unsafe:nnn #1#2#3
+\cs_new:Npn \str_range_ignore_spaces:nnn #1
+  { \exp_args:No \@@_range_unsafe:nnn { \tl_to_str:n {#1} } }
+\cs_new:Npn \@@_range_unsafe:nnn #1#2#3
   {
-    \exp_after:wN \@@_substr:www
+    \exp_after:wN \@@_range:www
     \__int_value:w \@@_count_unsafe:n {#1} \exp_after:wN ;
-    \int_use:N \__int_eval:w #2 + \c_zero \exp_after:wN ;
-    \int_use:N \__int_eval:w
-      \exp_args:Nf \@@_substr:nN {#3} \c_max_int ;
-      { } #1
-    \q_stop
+    \int_use:N \__int_eval:w #2 - \c_one \exp_after:wN ;
+    \int_use:N \__int_eval:w #3 ;
+    #1 \q_stop
   }
-\cs_new:Npn \@@_substr:nN #1 #2
-  { \tl_if_empty:nTF {#1} {#2} {#1} }
-\cs_new:Npn \@@_substr:www #1; #2; #3;
+\cs_new:Npn \@@_range:www #1; #2; #3;
   {
-    \exp_args:Nf \@@_substr:nnw
-      { \@@_substr_normalize_range:nn {#2} {#1} }
-      { \@@_substr_normalize_range:nn {#3} {#1} }
+    \exp_args:Nf \@@_range:nnw
+      { \@@_range_normalize:nn {#2} {#1} }
+      { \@@_range_normalize:nn {#3} {#1} }
   }
-\cs_new:Npn \@@_substr:nnw #1#2
+\cs_new:Npn \@@_range:nnw #1#2
   {
     \exp_after:wN \@@_collect_delimit_by_q_stop:w
-    \int_use:N \__int_eval:w #2 + \c_one - #1 \exp_after:wN ;
+    \int_use:N \__int_eval:w #2 - #1 \exp_after:wN ;
     \tex_romannumeral:D \@@_skip_c_zero:w #1 ;
   }
-\cs_new:Npn \@@_substr_normalize_range:nn #1#2
-  {
-    \int_eval:n
-      {
-        \if_int_compare:w #1 < \c_zero
-          \if_int_compare:w #1 < - #2 \exp_stop_f:
-            \c_zero
-          \else:
-            #1 + #2 + \c_one
-          \fi:
-        \else:
-          \if_int_compare:w #1 > #2 \exp_stop_f:
-            #2
-          \else:
-            #1
-          \fi:
-        \fi:
-      }
-  }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
 % \subsection{String conditionals}
 %
-% \begin{macro}[EXP,pTF]{\str_if_eq:NN}
-% \begin{macro}[EXP,pTF]{\str_if_eq:nn,\str_if_eq_x:nn}
+% \begin{macro}[EXP, pTF]{\str_if_eq:NN}
+% \begin{macro}[EXP, pTF]{\str_if_eq:nn, \str_if_eq_x:nn}
 %   Note that \cs{str_if_eq:NN} is different from
 %   \cs{tl_if_eq:NN} because it needs to ignore category codes.
 %    \begin{macrocode}
@@ -1305,109 +1013,10 @@
 % \end{macro}
 % \end{macro}
 %
-% \begin{macro}{\str_case:nnn, \str_case:onn, \str_case_x:nnn}
+% \begin{macro}[EXP]{\str_case:nnn, \str_case:onn, \str_case_x:nnn}
 %   Defined in \pkg{l3basics} at present.
 % \end{macro}
 %
-% \begin{macro}[EXP]{\@@_if_contains_char:NNT, \@@_if_contains_char:NNTF}
-% \begin{macro}[EXP]{\@@_if_contains_char:nNTF}
-% \begin{macro}[EXP,aux]{\@@_if_contains_char_aux:NN}
-% \begin{macro}[EXP,aux]{\@@_if_contains_char_true:}
-%   \begin{syntax}
-%     \cs{@@_if_contains_char:nNTF} \Arg{token list} \meta{char}
-%   \end{syntax}
-%   Expects the \meta{token list} to be an \meta{other string}: the
-%   caller is responsible for ensuring that no (too-)special catcodes
-%   remain.  Spaces with catcode $10$ are ignored.
-%   Loop over the characters of the string, comparing character codes.
-%   The loop is broken if character codes match. Otherwise we return
-%   \enquote{false}.
-%    \begin{macrocode}
-\prg_new_conditional:Npnn \@@_if_contains_char:NN #1#2 { T , TF }
-  {
-    \exp_after:wN \@@_if_contains_char_aux:NN \exp_after:wN #2
-      #1 { \__prg_break:n { ? \fi: } }
-    \__prg_break_point:
-    \prg_return_false:
-  }
-\prg_new_conditional:Npnn \@@_if_contains_char:nN #1#2 { TF }
-  {
-    \@@_if_contains_char_aux:NN #2 #1 { \__prg_break:n { ? \fi: } }
-    \__prg_break_point:
-    \prg_return_false:
-  }
-\cs_new:Npn \@@_if_contains_char_aux:NN #1#2
-  {
-    \if_charcode:w #1 #2
-      \exp_after:wN \@@_if_contains_char_true:
-    \fi:
-    \@@_if_contains_char_aux:NN #1
-  }
-\cs_new_nopar:Npn \@@_if_contains_char_true:
-  { \__prg_break:n { \prg_return_true: \use_none:n } }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[aux, rEXP]{\@@_octal_use:NTF}
-%   \begin{syntax}
-%     \cs{@@_octal_use:NTF} \meta{token} \Arg{true code} \Arg{false code}
-%   \end{syntax}
-%   If the \meta{token} is an octal digit, it is left in the input
-%   stream, \emph{followed} by the \meta{true code}. Otherwise, the
-%   \meta{false code} is left in the input stream.
-%   \begin{texnote}
-%     This function will fail if the escape character is an octal
-%     digit. We are thus careful to set the escape character to a known
-%     value before using it.
-%   \end{texnote}
-%   \TeX{} dutifully detects octal digits for us: if |#1| is an octal
-%   digit, then the right-hand side of the comparison is |'1#1|, greater
-%   than $1$. Otherwise, the right-hand side stops as |'1|, and the
-%   conditional takes the \texttt{false} branch.
-%    \begin{macrocode}
-\prg_new_conditional:Npnn \@@_octal_use:N #1 { TF }
-  {
-    \if_int_compare:w \c_one < '1 \token_to_str:N #1 \exp_stop_f:
-      #1 \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[aux, rEXP]{\@@_hexadecimal_use:NTF}
-%   \TeX{} detects uppercase hexadecimal digits for us (see
-%   \cs{@@_octal_use:NTF}), but not the lowercase letters, which we
-%   need to detect and replace by their uppercase counterpart.
-%    \begin{macrocode}
-\prg_new_conditional:Npnn \@@_hexadecimal_use:N #1 { TF }
-  {
-    \if_int_compare:w \c_two < "1 \token_to_str:N #1 \exp_stop_f:
-      #1 \prg_return_true:
-    \else:
-      \if_case:w \__int_eval:w
-          \exp_after:wN ` \token_to_str:N #1 - `a
-        \__int_eval_end:
-           A
-      \or: B
-      \or: C
-      \or: D
-      \or: E
-      \or: F
-      \else:
-        \prg_return_false:
-        \exp_after:wN \use_none:n
-      \fi:
-      \prg_return_true:
-    \fi:
-  }
-%    \end{macrocode}
-% \end{macro}
-%
 % \subsection{Viewing strings}
 %
 % \begin{macro}{\str_show:n, \str_show:N, \str_show:c}
@@ -1419,3084 +1028,41 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \subsection{Conversions}
-%
-% \subsubsection{Producing one byte or character}
-%
-% \begin{variable}{\c_@@_byte_0_tl, \c_@@_byte_1_tl, \c_@@_byte_255_tl}
-% \begin{variable}{\c_@@_byte_-1_tl}
-%   For each integer $N$ in the range $[0,255]$, we create a constant
-%   token list which holds three character tokens with category code
-%   other: the character with character code $N$, followed by the
-%   representation of $N$ as two hexadecimal digits.  The value $-1$ is
-%   given a default token list which ensures that later functions give
-%   an empty result for the input $-1$.
-%    \begin{macrocode}
-\group_begin:
-  \char_set_catcode_other:n { \c_zero }
-  \tl_set:Nx \l_@@_internal_tl { \tl_to_str:n { 0123456789ABCDEF } }
-  \exp_args:No \tl_map_inline:nn { \l_@@_internal_tl " }
-    { \char_set_lccode:nn {`#1} { \c_zero } }
-  \tl_map_inline:Nn \l_@@_internal_tl
-    {
-      \tl_map_inline:Nn \l_@@_internal_tl
-        {
-          \char_set_lccode:nn { \c_zero } {"#1##1}
-          \tl_to_lowercase:n
-            {
-              \tl_const:cx
-                { c_@@_byte_ \int_eval:n {"#1##1} _tl }
-                { ^^@ #1 ##1 }
-            }
-        }
-    }
-\group_end:
-\tl_const:cn { c_@@_byte_-1_tl } { { } \use_none:n { } }
-%    \end{macrocode}
-% \end{variable}
-% \end{variable}
-%
-% \begin{macro}[int, EXP]{\@@_output_byte:n}
-% \begin{macro}[int, EXP]{\@@_output_byte:w}
-% \begin{macro}[int, EXP]{\@@_output_hexadecimal:n}
-% \begin{macro}[int, EXP]{\@@_output_hexadecimal:w}
-% \begin{macro}[int, EXP]{\@@_output_end:}
-%   Those functions must be used carefully: feeding them a value outside
-%   the range $[-1,255]$ will attempt to use the undefined token list
-%   variable \cs{c_@@_byte_\meta{number}_tl}. Assuming that the
-%   argument is in the right range, we expand the corresponding token
-%   list, and pick either the byte (first token) or the hexadecimal
-%   representations (second and third tokens). The value $-1$ produces
-%   an empty result in both cases.
-%    \begin{macrocode}
-\cs_new:Npn \@@_output_byte:n #1
-  { \@@_output_byte:w #1 \@@_output_end: }
-\cs_new_nopar:Npn \@@_output_byte:w
-  {
-    \exp_after:wN \exp_after:wN
-    \exp_after:wN \use_i:nnn
-    \cs:w c_@@_byte_ \int_use:N \__int_eval:w
-  }
-\cs_new:Npn \@@_output_hexadecimal:n #1
-  { \@@_output_hexadecimal:w #1 \@@_output_end: }
-\cs_new_nopar:Npn \@@_output_hexadecimal:w
-  {
-    \exp_after:wN \exp_after:wN
-    \exp_after:wN \use_none:n
-    \cs:w c_@@_byte_ \int_use:N \__int_eval:w
-  }
-\cs_new_nopar:Npn \@@_output_end:
-  { \__int_eval_end: _tl \cs_end: }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int, rEXP]{\@@_output_byte_pair_be:n}
-% \begin{macro}[int, rEXP]{\@@_output_byte_pair_le:n}
-% \begin{macro}[aux, rEXP]{\@@_output_byte_pair:nnN}
-%   Convert a number in the range $[0,65535]$ to a pair of bytes, either
-%   big-endian or little-endian.
-%    \begin{macrocode}
-\cs_new:Npn \@@_output_byte_pair_be:n #1
-  {
-    \exp_args:Nf \@@_output_byte_pair:nnN
-      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use:nn
-  }
-\cs_new:Npn \@@_output_byte_pair_le:n #1
-  {
-    \exp_args:Nf \@@_output_byte_pair:nnN
-      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use_ii_i:nn
-  }
-\cs_new:Npn \@@_output_byte_pair:nnN #1#2#3
-  {
-    #3
-      { \@@_output_byte:n { #1 } }
-      { \@@_output_byte:n { #2 - #1 * "100 } }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \subsubsection{Mapping functions for conversions}
-%
-% \begin{macro}{\@@_convert_gmap:N}
-% \begin{macro}[aux, rEXP]{\@@_convert_gmap_loop:NN}
-%   This maps the function |#1| over all characters in
-%   \cs{g_@@_result_tl}, which should be a byte string in most cases,
-%   sometimes a native string.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_convert_gmap:N #1
-  {
-    \tl_gset:Nx \g_@@_result_tl
-      {
-        \exp_after:wN \@@_convert_gmap_loop:NN
-        \exp_after:wN #1
-          \g_@@_result_tl { ? \__prg_break: }
-        \__prg_break_point:
-      }
-  }
-\cs_new:Npn \@@_convert_gmap_loop:NN #1#2
-  {
-    \use_none:n #2
-    #1#2
-    \@@_convert_gmap_loop:NN #1
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_convert_gmap_internal:N}
-% \begin{macro}[aux, rEXP]{\@@_convert_gmap_internal_loop:Nw}
-%   This maps the function |#1| over all character codes in
-%   \cs{g_@@_result_tl}, which must be in the internal representation.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_convert_gmap_internal:N #1
-  {
-    \tl_gset:Nx \g_@@_result_tl
-      {
-        \exp_after:wN \@@_convert_gmap_internal_loop:Nww
-        \exp_after:wN #1
-          \g_@@_result_tl \s__tl \q_stop \__prg_break: \s__tl
-        \__prg_break_point:
-      }
-  }
-\cs_new:Npn \@@_convert_gmap_internal_loop:Nww #1 #2 \s__tl #3 \s__tl
-  {
-    \use_none_delimit_by_q_stop:w #3 \q_stop
-    #1 {#3}
-    \@@_convert_gmap_internal_loop:Nww #1
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsubsection{Error-reporting during conversion}
-%
-% \begin{macro}[int]{\@@_if_flag_error:nnx}
-% \begin{macro}[aux]{\@@_if_flag_no_error:nnx}
-%   When converting using the function \cs{str_set_convert:Nnnn}, errors
-%   should be reported to the user after each step in the
-%   conversion. Errors are signalled by raising some flag (typically
-%   \texttt{@@_error}), so here we test that flag: if it is raised,
-%   give the user an error, otherwise remove the arguments. On the other
-%   hand, in the conditional functions \cs{str_set_convert:NnnnTF},
-%   errors should be suppressed. This is done by changing
-%   \cs{@@_if_flag_error:nnx} into \cs{@@_if_flag_no_error:nnx}
-%   locally.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_if_flag_error:nnx #1
-  {
-    \flag_if_raised:nTF {#1}
-      { \__msg_kernel_error:nnx { str } }
-      { \use_none:nn }
-  }
-\cs_new_protected:Npn \@@_if_flag_no_error:nnx #1#2#3
-  { \flag_if_raised:nT {#1} { \bool_gset_true:N \g_@@_error_bool } }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_if_flag_times:nT}
-%   At the end of each conversion step, we raise all relevant errors as
-%   one error message, built on the fly. The height of each flag
-%   indicates how many times a given error was encountered. This
-%   function prints |#2| followed by the number of occurrences of an
-%   error if it occurred, nothing otherwise.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_if_flag_times:nT #1#2
-  { \flag_if_raised:nT {#1} { #2~(x \flag_height:n {#1} ) } }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsubsection{Framework for conversions}
-%
-% Most functions in this module expect to be working with
-% \enquote{native} strings. Strings can also be stored as bytes, in one
-% of many encodings, for instance \textsc{utf8}.  The bytes themselves
-% can be expressed in various ways in terms of \TeX{} tokens, for
-% instance as pairs of hexadecimal digits. The questions of going from
-% arbitrary Unicode code points to bytes, and from bytes to tokens are
-% mostly independent.
-%
-% Conversions are done in four steps:
-% \begin{itemize}
-%   \item \enquote{unescape} produces a string of bytes;
-%   \item \enquote{decode} takes in a string of bytes, and converts it
-%     to a list of Unicode characters in an internal representation,
-%     with items of the form
-%     \begin{quote}
-%       \meta{bytes} \cs{s__tl} \meta{Unicode code point} \cs{s__tl}
-%     \end{quote}
-%     where we have collected the \meta{bytes} which combined to form
-%     this particular Unicode character, and the \meta{Unicode code
-%       point} is in the range $[0,\hexnum{10FFFF}]$.
-%   \item \enquote{encode} encodes the internal list of code points as a
-%     byte string in the new encoding;
-%   \item \enquote{escape} escapes bytes as requested.
-% \end{itemize}
-% The process is modified in case one of the encoding is empty (or the
-% conversion function has been set equal to the empty encoding because
-% it was not found): then the unescape or escape step is ignored, and
-% the decode or encode steps work on tokens instead of bytes. Otherwise,
-% each step must ensure that it passes a correct byte string or internal
-% string to the next step.
-%
-% \begin{macro}{\str_set_convert:Nnnn, \str_gset_convert:Nnnn}
-% \begin{macro}[TF]{\str_set_convert:Nnnn, \str_gset_convert:Nnnn}
-% \begin{macro}[aux]{\@@_convert:nNNnnn}
-%   The input string is stored in \cs{g_@@_result_tl}, then we:
-%   unescape and decode; encode and escape; exit the group and store the
-%   result in the user's variable. The various conversion functions all
-%   act on \cs{g_@@_result_tl}. Errors are silenced for the conditional
-%   functions by redefining \cs{@@_if_flag_error:nnx} locally.
-%    \begin{macrocode}
-\cs_new_protected_nopar:Npn \str_set_convert:Nnnn
-  { \@@_convert:nNNnnn { } \tl_set_eq:NN }
-\cs_new_protected_nopar:Npn \str_gset_convert:Nnnn
-  { \@@_convert:nNNnnn { } \tl_gset_eq:NN }
-\prg_new_protected_conditional:Npnn
-    \str_set_convert:Nnnn #1#2#3#4 { T , F , TF }
-  {
-    \bool_gset_false:N \g_@@_error_bool
-    \@@_convert:nNNnnn
-      { \cs_set_eq:NN \@@_if_flag_error:nnx \@@_if_flag_no_error:nnx }
-      \tl_set_eq:NN #1 {#2} {#3} {#4}
-    \bool_if:NTF \g_@@_error_bool \prg_return_false: \prg_return_true:
-  }
-\prg_new_protected_conditional:Npnn
-    \str_gset_convert:Nnnn #1#2#3#4 { T , F , TF }
-  {
-    \bool_gset_false:N \g_@@_error_bool
-    \@@_convert:nNNnnn
-      { \cs_set_eq:NN \@@_if_flag_error:nnx \@@_if_flag_no_error:nnx }
-      \tl_gset_eq:NN #1 {#2} {#3} {#4}
-    \bool_if:NTF \g_@@_error_bool \prg_return_false: \prg_return_true:
-  }
-\cs_new_protected:Npn \@@_convert:nNNnnn #1#2#3#4#5#6
-  {
-    \group_begin:
-      #1
-      \@@_gset_other:Nn \g_@@_result_tl {#4}
-      \exp_after:wN \@@_convert:wwwnn
-        \tl_to_str:n {#5} /// \q_stop
-        { decode } { unescape }
-        \prg_do_nothing:
-        \@@_convert_decode_:
-      \exp_after:wN \@@_convert:wwwnn
-        \tl_to_str:n {#6} /// \q_stop
-        { encode } { escape }
-        \use_ii_i:nn
-        \@@_convert_encode_:
-    \group_end:
-    #2 #3 \g_@@_result_tl
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[aux]{\@@_convert:wwwnn}
-% \begin{macro}[aux]{\@@_convert:NNnNN}
-%   The task of \cs{@@_convert:wwwnn} is to split
-%   \meta{encoding}/\meta{escaping} pairs into their components, |#1|
-%   and |#2|. Calls to \cs{@@_convert:nnn} ensure that the
-%   corresponding conversion functions are defined. The third auxiliary
-%   does the main work.
-%   \begin{itemize}
-%     \item |#1| is the encoding conversion function;
-%     \item |#2| is the escaping function;
-%     \item |#3| is the escaping name for use in an error message;
-%     \item |#4| is \cs{prg_do_nothing:} for unescaping/decoding, and
-%       \cs{use_ii_i:nn} for encoding/escaping;
-%     \item |#5| is the default encoding function (either
-%       \enquote{decode} or \enquote{encode}), for which there should be
-%       no escaping.
-%   \end{itemize}
-%   Let us ignore the native encoding for a second. In the
-%   unescaping/decoding phase, we want to do |#2#1| in this order, and
-%   in the encoding/escaping phase, the order should be reversed:
-%   |#4#2#1| does exactly that. If one of the encodings is the default
-%   (native), then the escaping should be ignored, with an error if any
-%   was given, and only the encoding, |#1|, should be performed.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_convert:wwwnn
-    #1 / #2 // #3 \q_stop #4#5
-  {
-    \@@_convert:nnn {enc} {#4} {#1}
-    \@@_convert:nnn {esc} {#5} {#2}
-    \exp_args:Ncc \@@_convert:NNnNN
-      { @@_convert_#4_#1: } { @@_convert_#5_#2: } {#2}
-  }
-\cs_new_protected:Npn \@@_convert:NNnNN #1#2#3#4#5
-  {
-    \if_meaning:w #1 #5
-      \tl_if_empty:nF {#3}
-        { \__msg_kernel_error:nnx { str } { native-escaping } {#3} }
-      #1
-    \else:
-      #4 #2 #1
-    \fi:
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[aux]{\@@_convert:nnn}
-% \begin{macro}[aux]{\@@_convert:nnnn}
-%   The arguments of \cs{@@_convert:nnn} are: \texttt{enc} or
-%   \texttt{esc}, used to build filenames, the type of the conversion
-%   (unescape, decode, encode, escape), and the encoding or escaping
-%   name. If the function is already defined, no need to do anything.
-%   Otherwise, filter out all non-alphanumerics in the name, and
-%   lowercase it. Feed that, and the same three arguments, to
-%   \cs{@@_convert:nnnn}. The task is then to make sure that the
-%   conversion function |#3_#1| corresponding to the type |#3| and
-%   filtered name |#1| is defined, then set our initial conversion
-%   function |#3_#4| equal to that.
-%
-%   How do we get the |#3_#1| conversion to be defined if it isn't?
-%   Two main cases.
-%
-%   First, if |#1| is a key in \cs{g_@@_alias_prop}, then the value
-%   \cs{l_@@_internal_tl} tells us what file to load. Loading is
-%   skipped if the file was already read, \emph{i.e.}, if the conversion
-%   command based on \cs{l_@@_internal_tl} already exists.  Otherwise,
-%   try to load the file; if that fails, there is an error, use the
-%   default empty name instead.
-%
-%   Second, |#1| may be absent from the property list. The
-%   \cs{cs_if_exist:cF} test is automatically false, and we search for a
-%   file defining the encoding or escaping |#1| (this should allow
-%   third-party \texttt{.def} files). If the file is not found, there is
-%   an error, use the default empty name instead.
-%
-%   In all cases, the conversion based on \cs{l_@@_internal_tl} is
-%   defined, so we can set the |#3_#1| function equal to that. In some
-%   cases (\emph{e.g.}, \texttt{utf16be}), the |#3_#1| function is
-%   actually defined within the file we just loaded, and it is different
-%   from the \cs{l_@@_internal_tl}-based function: we mustn't clobber
-%   that different definition.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_convert:nnn #1#2#3
-  {
-    \cs_if_exist:cF { @@_convert_#2_#3: }
-      {
-        \exp_args:Nx \@@_convert:nnnn
-          { \@@_convert_lowercase_alphanum:n {#3} }
-          {#1} {#2} {#3}
-      }
-  }
-\cs_new_protected:Npn \@@_convert:nnnn #1#2#3#4
-  {
-    \cs_if_exist:cF { @@_convert_#3_#1: }
-      {
-        \prop_get:NnNF \g_@@_alias_prop {#1} \l_@@_internal_tl
-          { \tl_set:Nn \l_@@_internal_tl {#1} }
-        \cs_if_exist:cF { @@_convert_#3_ \l_@@_internal_tl : }
-          {
-            \file_if_exist:nTF { l3str-#2- \l_@@_internal_tl .def }
-              {
-                \group_begin:
-                  \@@_load_catcodes:
-                  \file_input:n { l3str-#2- \l_@@_internal_tl .def }
-                \group_end:
-              }
-              {
-                \tl_clear:N \l_@@_internal_tl
-                \__msg_kernel_error:nnxx { str } { unknown-#2 } {#4} {#1}
-              }
-          }
-        \cs_if_exist:cF { @@_convert_#3_#1: }
-          {
-            \cs_gset_eq:cc { @@_convert_#3_#1: }
-              { @@_convert_#3_ \l_@@_internal_tl : }
-          }
-      }
-    \cs_gset_eq:cc { @@_convert_#3_#4: } { @@_convert_#3_#1: }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int, rEXP]{\@@_convert_lowercase_alphanum:n}
-% \begin{macro}[aux, rEXP]{\@@_convert_lowercase_alphanum_loop:N}
-%   This function keeps only letters and digits, with upper case letters
-%   converted to lower case.
-%    \begin{macrocode}
-\cs_new:Npn \@@_convert_lowercase_alphanum:n #1
-  {
-    \exp_after:wN \@@_convert_lowercase_alphanum_loop:N
-      \tl_to_str:n {#1} { ? \__prg_break: }
-    \__prg_break_point:
-  }
-\cs_new:Npn \@@_convert_lowercase_alphanum_loop:N #1
-  {
-    \use_none:n #1
-    \if_int_compare:w `#1 < \c_ninety_one
-      \if_int_compare:w `#1 < \c_sixty_five
-        \if_int_compare:w \c_one < 1#1 \exp_stop_f:
-          #1
-        \fi:
-      \else:
-        \@@_output_byte:n { `#1 + \c_thirty_two }
-      \fi:
-    \else:
-      \if_int_compare:w `#1 < \c_one_hundred_twenty_three
-        \if_int_compare:w `#1 < \c_ninety_seven
-        \else:
-          #1
-        \fi:
-      \fi:
-    \fi:
-    \@@_convert_lowercase_alphanum_loop:N
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_load_catcodes:}
-%   Since encoding files may be loaded at arbitrary places in a \TeX{}
-%   document, including within verbatim mode, we set the catcodes of all
-%   characters appearing in any encoding definition file.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_load_catcodes:
-  {
-    \char_set_catcode_escape:N \\
-    \char_set_catcode_group_begin:N \{
-    \char_set_catcode_group_end:N \}
-    \char_set_catcode_math_toggle:N \$
-    \char_set_catcode_alignment:N \&
-    \char_set_catcode_parameter:N \#
-    \char_set_catcode_math_superscript:N \^
-    \char_set_catcode_ignore:N \ %
-    \char_set_catcode_space:N \~
-    \tl_map_function:nN { abcdefghijklmnopqrstuvwxyz_:ABCDEFILNPSTUX }
-      \char_set_catcode_letter:N
-    \tl_map_function:nN { 0123456789"'?*+-.(),`!/<>[];= }
-      \char_set_catcode_other:N
-    \char_set_catcode_comment:N \%
-    \int_set:Nn \tex_endlinechar:D {32}
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsubsection{Byte unescape and escape}
-%
-% Strings of bytes may need to be stored in auxiliary files in safe
-% \enquote{escaping} formats. Each such escaping is only loaded as
-% needed. By default, on input any non-byte is filtered out, while the
-% output simply consists in letting bytes through.
-%
-% \begin{macro}[int, rEXP]{\@@_filter_bytes:n}
-% \begin{macro}[aux, rEXP]{\@@_filter_bytes_aux:N}
-%   In the case of pdf\TeX{}, every character is a byte.  For
-%   Unicode-aware engines, test the character code; non-bytes cause us
-%   to raise the flag \texttt{str_byte}.  Spaces have already been given
-%   the correct category code when this function is called.
-%    \begin{macrocode}
-\pdftex_if_engine:TF
-  { \cs_new_eq:NN \@@_filter_bytes:n \use:n }
-  {
-    \cs_new:Npn \@@_filter_bytes:n #1
-      {
-        \@@_filter_bytes_aux:N #1
-          { ? \__prg_break: }
-        \__prg_break_point:
-      }
-    \cs_new:Npn \@@_filter_bytes_aux:N #1
-      {
-        \use_none:n #1
-        \if_int_compare:w `#1 < 256 \exp_stop_f:
-          #1
-        \else:
-          \flag_raise:n { str_byte }
-        \fi:
-        \@@_filter_bytes_aux:N
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_unescape_:}
-% \begin{macro}[int]{\@@_convert_unescape_bytes:}
-%   The simplest unescaping method removes non-bytes from
-%   \cs{g_@@_result_tl}.
-%    \begin{macrocode}
-\pdftex_if_engine:TF
-  { \cs_new_protected_nopar:Npn \@@_convert_unescape_: { } }
-  {
-    \cs_new_protected_nopar:Npn \@@_convert_unescape_:
-      {
-        \flag_clear:n { str_byte }
-        \tl_gset:Nx \g_@@_result_tl
-          { \exp_args:No \@@_filter_bytes:n \g_@@_result_tl }
-        \@@_if_flag_error:nnx { str_byte } { non-byte } { bytes }
-      }
-  }
-\cs_new_eq:NN \@@_convert_unescape_bytes: \@@_convert_unescape_:
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_escape_:}
-% \begin{macro}[int]{\@@_convert_escape_bytes:}
-%   The simplest form of escape leaves the bytes from the previous step
-%   of the conversion unchanged.
-%    \begin{macrocode}
-\cs_new_protected_nopar:Npn \@@_convert_escape_: { }
-\cs_new_eq:NN \@@_convert_escape_bytes: \@@_convert_escape_:
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsubsection{Native strings}
-%
-% \begin{macro}[int]{\@@_convert_decode_:}
-% \begin{macro}[aux, rEXP]{\@@_decode_native_char:N}
-%   Convert each character to its character code, one at a time.
-%    \begin{macrocode}
-\cs_new_protected_nopar:Npn \@@_convert_decode_:
-  { \@@_convert_gmap:N \@@_decode_native_char:N }
-\cs_new:Npn \@@_decode_native_char:N #1
-  { #1 \s__tl \__int_value:w `#1 \s__tl }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_encode_:}
-%   The conversion from an internal string to native character tokens is
-%   very different in pdf\TeX{} and in other engines. For Unicode-aware
-%   engines, we need the definitions to be read when the null byte has
-%   category code $12$, so we set that inside a group.
-%    \begin{macrocode}
-\group_begin:
-  \char_set_catcode_other:n { 0 }
-  \pdftex_if_engine:TF
-%    \end{macrocode}
-% \begin{macro}[aux, EXP]{\@@_encode_native_char:n}
-%   Since pdf\TeX{} only supports 8-bit characters, and we have a table
-%   of all bytes, the conversion can be done in linear time within an
-%   \texttt{x}-expanding assignment. Look out for character codes larger
-%   than $255$, those characters are replaced by |?|, and raise a flag,
-%   which then triggers a pdf\TeX{}-specific error.
-%    \begin{macrocode}
-    {
-      \cs_new_protected_nopar:Npn \@@_convert_encode_:
-        {
-          \flag_clear:n { str_error }
-          \@@_convert_gmap_internal:N \@@_encode_native_char:n
-          \@@_if_flag_error:nnx { str_error }
-            { pdfTeX-native-overflow } { }
-        }
-      \cs_new:Npn \@@_encode_native_char:n #1
-        {
-          \if_int_compare:w #1 < \c_two_hundred_fifty_six
-            \@@_output_byte:n {#1}
-          \else:
-            \flag_raise:n { str_error }
-            ?
-          \fi:
-        }
-      \__msg_kernel_new:nnnn { str } { pdfTeX-native-overflow }
-        { Character~code~too~large~for~pdfTeX. }
-        {
-          The~pdfTeX~engine~only~supports~8-bit~characters:~
-          valid~character~codes~are~in~the~range~[0,255].~
-          To~manipulate~arbitrary~Unicode,~use~LuaTeX~or~XeTeX.
-        }
-    }
-%    \end{macrocode}
-% \end{macro}
-% \begin{macro}[aux]{\@@_encode_native_loop:w}
-% \begin{macro}[aux]{\@@_encode_native_flush:}
-% \begin{macro}[aux, rEXP]{\@@_encode_native_filter:N}
-%   In Unicode-aware engines, since building particular characters
-%   cannot be done expandably in \TeX{}, we cannot hope to get a
-%   linear-time function. However, we get quite close using the
-%   \pkg{l3tl-build} module, which abuses \tn{toks} to reach an almost
-%   linear time. Use the standard lowercase trick to produce an
-%   arbitrary character from the null character, and add that character
-%   to the end of the token list being built. At the end of the loop,
-%   put the token list together with \cs{__tl_build_end:}. Note that we
-%   use an \texttt{x}-expanding assignment because it is slightly
-%   faster. Unicode-aware engines will never incur an overflow because
-%   the internal string is guaranteed to only contain code points in
-%   $[0,\hexnum{10FFFF}]$.
-%    \begin{macrocode}
-    {
-      \cs_new_protected_nopar:Npn \@@_convert_encode_:
-        {
-          \int_zero:N \l__tl_build_offset_int
-          \__tl_gbuild_x:Nw \g_@@_result_tl
-            \exp_after:wN \@@_encode_native_loop:w
-              \g_@@_result_tl \s__tl { \q_stop \__prg_break: } \s__tl
-            \__prg_break_point:
-          \__tl_build_end:
-        }
-      \cs_new_protected:Npn \@@_encode_native_loop:w #1 \s__tl #2 \s__tl
-        {
-          \use_none_delimit_by_q_stop:w #2 \q_stop
-          \tex_lccode:D \l_@@_internal_int \__int_eval:w #2 \__int_eval_end:
-          \tl_to_lowercase:n { \__tl_build_one:n { ^^@ } }
-          \@@_encode_native_loop:w
-        }
-    }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%   End the group to restore the catcode of the null byte.
-%    \begin{macrocode}
-\group_end:
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsubsection{8-bit encodings}
-%
-% This section will be entirely rewritten: it is not yet clear in what
-% situations 8-bit encodings are used, hence I don't know what exactly
-% should be optimized. The current approach is reasonably efficient to
-% convert long strings, and it scales well when using many different
-% encodings. An approach based on csnames would have a smaller constant
-% load time for each individual conversion, but has a large hash table
-% cost. Using a range of \tn{count} registers works for decoding, but
-% not for encoding: one possibility there would be to use a binary tree
-% for the mapping of Unicode characters to bytes, stored as a box, one
-% per encoding.
-%
-% Since the section is going to be rewritten, documentation lacks.
-%
-% All the 8-bit encodings which \pkg{l3str} supports rely on the same
-% internal functions.
-%
-% \begin{macro}[int]{\@@_declare_eight_bit_encoding:nnn}
-%   \begin{syntax}
-%     \cs{@@_declare_eight_bit_encoding:nnn} \Arg{name} \Arg{mapping} \Arg{missing}
-%   \end{syntax}
-%   This declares the encoding \meta{name} to map bytes to Unicode
-%   characters according to the \meta{mapping}, and map those bytes
-%   which are not mentionned in the \meta{mapping} either to the
-%   replacement character (if they appear in \meta{missing}), or to
-%   themselves.
-%
-%   All the 8-bit encoding definition file start with
-%   \cs{@@_declare_eight_bit_encoding:nnn} \Arg{encoding name}
-%   \Arg{mapping} \Arg{missing bytes}.  The \meta{mapping} argument is a
-%   token list of pairs \Arg{byte} \Arg{Unicode} expressed in uppercase
-%   hexadecimal notation.  The \meta{missing} argument is a token list
-%   of \Arg{byte}. Every \meta{byte} which does not appear in the
-%   \meta{mapping} nor the \meta{missing} lists maps to the same code
-%   point in Unicode.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_eight_bit_encoding:nnn #1#2#3
-  {
-    \tl_set:Nn \l_@@_internal_tl {#1}
-    \cs_new_protected_nopar:cpn { @@_convert_decode_#1: }
-      { \@@_convert_decode_eight_bit:n {#1} }
-    \cs_new_protected_nopar:cpn { @@_convert_encode_#1: }
-      { \@@_convert_encode_eight_bit:n {#1} }
-    \tl_const:cn { c_@@_encoding_#1_tl } {#2}
-    \tl_const:cn { c_@@_encoding_#1_missing_tl } {#3}
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_decode_eight_bit:n}
-% \begin{macro}[aux]{\@@_decode_eight_bit_load:nn}
-% \begin{macro}[aux]{\@@_decode_eight_bit_load_missing:n}
-% \begin{macro}[aux, EXP]{\@@_decode_eight_bit_char:N}
-%^^A todo: document
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_convert_decode_eight_bit:n #1
-  {
-    \group_begin:
-      \int_zero:N \l_@@_internal_int
-      \exp_last_unbraced:Nx \@@_decode_eight_bit_load:nn
-        { \tl_use:c { c_@@_encoding_#1_tl } }
-        { \q_stop \__prg_break: } { }
-      \__prg_break_point:
-      \exp_last_unbraced:Nx \@@_decode_eight_bit_load_missing:n
-        { \tl_use:c { c_@@_encoding_#1_missing_tl } }
-        { \q_stop \__prg_break: }
-      \__prg_break_point:
-      \flag_clear:n { str_error }
-      \@@_convert_gmap:N \@@_decode_eight_bit_char:N
-      \@@_if_flag_error:nnx { str_error } { decode-8-bit } {#1}
-    \group_end:
-  }
-\cs_new_protected:Npn \@@_decode_eight_bit_load:nn #1#2
-  {
-    \use_none_delimit_by_q_stop:w #1 \q_stop
-    \tex_dimen:D "#1 = \l_@@_internal_int sp \scan_stop:
-    \tex_skip:D \l_@@_internal_int = "#1 sp \scan_stop:
-    \tex_toks:D \l_@@_internal_int \exp_after:wN { \__int_value:w "#2 }
-    \tex_advance:D \l_@@_internal_int \c_one
-    \@@_decode_eight_bit_load:nn
-  }
-\cs_new_protected:Npn \@@_decode_eight_bit_load_missing:n #1
-  {
-    \use_none_delimit_by_q_stop:w #1 \q_stop
-    \tex_dimen:D "#1 = \l_@@_internal_int sp \scan_stop:
-    \tex_skip:D \l_@@_internal_int = "#1 sp \scan_stop:
-    \tex_toks:D \l_@@_internal_int \exp_after:wN
-      { \int_use:N \c_@@_replacement_char_int }
-    \tex_advance:D \l_@@_internal_int \c_one
-    \@@_decode_eight_bit_load_missing:n
-  }
-\cs_new:Npn \@@_decode_eight_bit_char:N #1
-  {
-    #1 \s__tl
-    \if_int_compare:w \tex_dimen:D `#1 < \l_@@_internal_int
-      \if_int_compare:w \tex_skip:D \tex_dimen:D `#1 = `#1 \exp_stop_f:
-        \tex_the:D \tex_toks:D \tex_dimen:D
-      \fi:
-    \fi:
-    \__int_value:w `#1 \s__tl
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_encode_eight_bit:n}
-% \begin{macro}[aux]{\@@_encode_eight_bit_load:nn}
-% \begin{macro}[aux, rEXP]{\@@_encode_eight_bit_char:n}
-% \begin{macro}[aux, rEXP]{\@@_encode_eight_bit_char_aux:n}
-%^^A todo: document
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_convert_encode_eight_bit:n #1
-  {
-    \group_begin:
-      \int_zero:N \l_@@_internal_int
-      \exp_last_unbraced:Nx \@@_encode_eight_bit_load:nn
-        { \tl_use:c { c_@@_encoding_#1_tl } }
-        { \q_stop \__prg_break: } { }
-      \__prg_break_point:
-      \flag_clear:n { str_error }
-      \@@_convert_gmap_internal:N \@@_encode_eight_bit_char:n
-      \@@_if_flag_error:nnx { str_error } { encode-8-bit } {#1}
-    \group_end:
-  }
-\cs_new_protected:Npn \@@_encode_eight_bit_load:nn #1#2
-  {
-    \use_none_delimit_by_q_stop:w #1 \q_stop
-    \tex_dimen:D "#2 = \l_@@_internal_int sp \scan_stop:
-    \tex_skip:D \l_@@_internal_int = "#2 sp \scan_stop:
-    \exp_args:NNf \tex_toks:D \l_@@_internal_int
-      { \@@_output_byte:n { "#1 } }
-    \tex_advance:D \l_@@_internal_int \c_one
-    \@@_encode_eight_bit_load:nn
-  }
-\cs_new:Npn \@@_encode_eight_bit_char:n #1
-  {
-    \if_int_compare:w #1 > \c_max_register_int
-      \flag_raise:n { str_error }
-    \else:
-      \if_int_compare:w \tex_dimen:D #1 < \l_@@_internal_int
-        \if_int_compare:w \tex_skip:D \tex_dimen:D #1 = #1 \exp_stop_f:
-          \tex_the:D \tex_toks:D \tex_dimen:D #1 \exp_stop_f:
-          \exp_after:wN \exp_after:wN \exp_after:wN \use_none:nn
-        \fi:
-      \fi:
-      \@@_encode_eight_bit_char_aux:n {#1}
-    \fi:
-  }
-\cs_new:Npn \@@_encode_eight_bit_char_aux:n #1
-  {
-    \if_int_compare:w #1 < \c_two_hundred_fifty_six
-      \@@_output_byte:n {#1}
-    \else:
-      \flag_raise:n { str_error }
-    \fi:
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Messages}
-%
-% General messages, and messages for the encodings and escapings loaded
-% by default (\enquote{native}, and \enquote{bytes}).
-%    \begin{macrocode}
-\__msg_kernel_new:nnn { str } { unknown-esc }
-  { Escaping~scheme~'#1'~(filtered:~'#2')~unknown. }
-\__msg_kernel_new:nnn { str } { unknown-enc }
-  { Encoding~scheme~'#1'~(filtered:~'#2')~unknown. }
-\__msg_kernel_new:nnnn { str } { native-escaping }
-  { The~'native'~encoding~scheme~does~not~support~any~escaping. }
-  {
-    Since~native~strings~do~not~consist~in~bytes,~
-    none~of~the~escaping~methods~make~sense.~
-    The~specified~escaping,~'#1',~will be ignored.
-  }
-\__msg_kernel_new:nnn { str } { file-not-found }
-  { File~'l3str-#1.def'~not~found. }
-%    \end{macrocode}
-%
-% Message used when the \enquote{bytes} unescaping fails because the
-% string given to \cs{str_set_convert:Nnnn} contains a non-byte. This
-% cannot happen for the pdf\TeX{} engine, since that engine only
-% supports 8-bit characters. Messages used for other escapings and
-% encodings are defined in each definition file.
-%    \begin{macrocode}
-\pdftex_if_engine:F
-  {
-    \__msg_kernel_new:nnnn { str } { non-byte }
-      { String~invalid~in~escaping~'#1':~it~may~only~contain~bytes. }
-      {
-        Some~characters~in~the~string~you~asked~to~convert~are~not~
-        8-bit~characters.~Perhaps~the~string~is~a~'native'~Unicode~string?~
-        If~it~is,~try~using\\
-        \\
-        \iow_indent:n
-          {
-            \iow_char:N\\str_set_convert:Nnnn \\
-            \ \ <str~var>~\{~<string>~\}~\{~native~\}~\{~<target~encoding>~\}
-          }
-      }
-  }
-%    \end{macrocode}
-%
-% Those messages are used when converting to and from 8-bit encodings.
-%    \begin{macrocode}
-\__msg_kernel_new:nnnn { str } { decode-8-bit }
-  { Invalid~string~in~encoding~'#1'. }
-  {
-    LaTeX~came~across~a~byte~which~is~not~defined~to~represent~
-    any~character~in~the~encoding~'#1'.
-  }
-\__msg_kernel_new:nnnn { str } { encode-8-bit }
-  { Unicode~string~cannot~be~converted~to~encoding~'#1'. }
-  {
-    The~encoding~'#1'~only~contains~a~subset~of~all~Unicode~characters.~
-    LaTeX~was~asked~to~convert~a~string~to~that~encoding,~but~that~
-    string~contains~a~character~that~'#1'~does~not~support.
-  }
-%    \end{macrocode}
-%
 % \subsection{Deprecated string functions}
-% 
-% Deprecated 2012-05-13 for removal by 2012-08-31.
-% 
-% \begin{macro}{\str_length:N, \str_length:n, \str_length_ignore_spaces:n}
-%    \begin{macrocode}
-\cs_new_eq:NN \str_length:N \str_count:N
-\cs_new_eq:NN \str_length:n \str_count:n
-\cs_new_eq:NN \str_length_ignore_spaces:n \str_count_ignore_spaces:n
-%    \end{macrocode}
-% \end{macro}
-%
-%    \begin{macrocode}
-%</initex|package>
-%    \end{macrocode}
-%
-% \subsection{Escaping definition files}
-%
-% Several of those encodings are defined by the pdf file format.  The
-% following byte storage methods are defined:
-% \begin{itemize}
-%   \item \texttt{bytes} (default), non-bytes are filtered out, and
-%     bytes are left untouched (this is defined by default);
-%   \item \texttt{hex} or \texttt{hexadecimal}, as per the pdf\TeX{}
-%     primitive \tn{pdfescapehex}
-%   \item \texttt{name}, as per the pdf\TeX{} primitive
-%     \tn{pdfescapename}
-%   \item \texttt{string}, as per the pdf\TeX{} primitive
-%     \tn{pdfescapestring}
-%   \item \texttt{url}, as per the percent encoding of urls.
-% \end{itemize}
-%
-% \subsubsection{Unescape methods}
-%
-% \begin{macro}[int]{\@@_convert_unescape_hex:}
-% \begin{macro}[aux, rEXP]{\@@_unescape_hex_auxi:N}
-% \begin{macro}[aux, rEXP]{\@@_unescape_hex_auxii:N}
-%   Take chars two by two, and interpret each pair as the hexadecimal
-%   code for a byte. Anything else than hexadecimal digits is ignored,
-%   raising the flag.  A string which contains an odd number of
-%   hexadecimal digits gets |0| appended to it: this is equivalent to
-%   appending a |0| in all cases, and dropping it if it is alone.
-%    \begin{macrocode}
-%<*hex>
-\cs_new_protected_nopar:Npn \@@_convert_unescape_hex:
-  {
-    \group_begin:
-      \flag_clear:n { str_error }
-      \int_set:Nn \tex_escapechar:D { 92 }
-      \tl_gset:Nx \g_@@_result_tl
-        {
-          \@@_output_byte:w "
-            \exp_last_unbraced:Nf \@@_unescape_hex_auxi:N
-              { \tl_to_str:N \g_@@_result_tl }
-            0 { ? 0 - \c_one \__prg_break: }
-            \__prg_break_point:
-          \@@_output_end:
-        }
-      \@@_if_flag_error:nnx { str_error } { unescape-hex } { }
-    \group_end:
-  }
-\cs_new:Npn \@@_unescape_hex_auxi:N #1
-  {
-    \use_none:n #1
-    \@@_hexadecimal_use:NTF #1
-      { \@@_unescape_hex_auxii:N }
-      {
-        \flag_raise:n { str_error }
-        \@@_unescape_hex_auxi:N
-      }
-  }
-\cs_new:Npn \@@_unescape_hex_auxii:N #1
-  {
-    \use_none:n #1
-    \@@_hexadecimal_use:NTF #1
-      {
-        \@@_output_end:
-        \@@_output_byte:w " \@@_unescape_hex_auxi:N
-      }
-      {
-        \flag_raise:n { str_error }
-        \@@_unescape_hex_auxii:N
-      }
-  }
-\__msg_kernel_new:nnnn { str } { unescape-hex }
-  { String~invalid~in~escaping~'hex':~only~hexadecimal~digits~allowed. }
-  {
-    Some~characters~in~the~string~you~asked~to~convert~are~not~
-    hexadecimal~digits~(0-9,~A-F,~a-f)~nor~spaces.
-  }
-%</hex>
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_unescape_name:}
-% \begin{macro}[aux, rEXP]{\@@_unescape_name_loop:wNN}
-% \begin{macro}[int]{\@@_convert_unescape_url:}
-% \begin{macro}[aux, rEXP]{\@@_unescape_url_loop:wNN}
-%   The \cs{@@_convert_unescape_name:} function replaces each
-%   occurrence of |#| followed by two hexadecimal digits in
-%   \cs{g_@@_result_tl} by the corresponding byte.  The \texttt{url}
-%   function is identical, with escape character |%| instead of |#|.
-%   Thus we define the two together. The arguments of \cs{@@_tmp:w} are
-%   the character code of |#| or |%| in hexadecimal, the name of the
-%   main function to define, and the name of the auxiliary which
-%   performs the loop.
-%
-%   The looping auxiliary |#3| finds the next escape character, reads
-%   the following two characters, and tests them. The test
-%   \cs{@@_hexadecimal_use:NTF} leaves the upper-case digit in the
-%   input stream, hence we surround the test with
-%   \cs{@@_output_byte:w}~|"| and \cs{@@_output_end:}.  If both
-%   characters are hexadecimal digits, they should be removed before
-%   looping: this is done by \cs{use_i:nnn}.  If one of the characters
-%   is not a hexadecimal digit, then feed |"#1| to
-%   \cs{@@_output_byte:w} to produce the escape character, raise the
-%   flag, and call the looping function followed by the two characters
-%   (remove \cs{use_i:nnn}).
-%    \begin{macrocode}
-%<*name|url>
-\cs_set_protected:Npn \@@_tmp:w #1#2#3
-  {
-    \cs_new_protected:cpn { @@_convert_unescape_#2: }
-      {
-        \group_begin:
-          \flag_clear:n { str_byte }
-          \flag_clear:n { str_error }
-          \int_set:Nn \tex_escapechar:D { 92 }
-          \tl_gset:Nx \g_@@_result_tl
-            {
-              \exp_after:wN #3 \g_@@_result_tl
-                #1 ? { ? \__prg_break: }
-              \__prg_break_point:
-            }
-          \@@_if_flag_error:nnx { str_byte } { non-byte } { #2 }
-          \@@_if_flag_error:nnx { str_error } { unescape-#2 } { }
-        \group_end:
-      }
-    \cs_new:Npn #3 ##1#1##2##3
-      {
-        \@@_filter_bytes:n {##1}
-        \use_none:n ##3
-        \@@_output_byte:w "
-          \@@_hexadecimal_use:NTF ##2
-            {
-              \@@_hexadecimal_use:NTF ##3
-                { }
-                {
-                  \flag_raise:n { str_error }
-                  * \c_zero + `#1 \use_i:nn
-                }
-            }
-            {
-              \flag_raise:n { str_error }
-              0 + `#1 \use_i:nn
-            }
-        \@@_output_end:
-        \use_i:nnn #3 ##2##3
-      }
-    \__msg_kernel_new:nnnn { str } { unescape-#2 }
-      { String~invalid~in~escaping~'#2'. }
-      {
-        LaTeX~came~across~the~escape~character~'#1'~not~followed~by~
-        two~hexadecimal~digits.~This~is~invalid~in~the~escaping~'#2'.
-      }
-  }
-%</name|url>
-%<*name>
-\exp_after:wN \@@_tmp:w \c_hash_str { name }
-  \@@_unescape_name_loop:wNN
-%</name>
-%<*url>
-\exp_after:wN \@@_tmp:w \c_percent_str { url }
-  \@@_unescape_url_loop:wNN
-%</url>
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_unescape_string:}
-% \begin{macro}[aux, rEXP]{\@@_unescape_string_newlines:wN}
-% \begin{macro}[aux, rEXP]{\@@_unescape_string_loop:wNNN}
-% \begin{macro}[aux, rEXP]{\@@_unescape_string_repeat:NNNNNN}
-%   The \texttt{string} escaping is somewhat similar to the
-%   \texttt{name} and \texttt{url} escapings, with escape character |\|.
-%   The first step is to convert all three line endings, |^^J|, |^^M|,
-%   and |^^M^^J| to the common |^^J|, as per the \textsc{pdf}
-%   specification.  This step cannot raise the flag.
-%
-%   Then the following escape sequences are decoded.
-%   \begin{itemize}\def\makelabel#1{\hss\llap{\ttfamily\string#1}}
-%     \item[\n] Line feed ($10$)
-%     \item[\r] Carriage return ($13$)
-%     \item[\t] Horizontal tab ($9$)
-%     \item[\b] Backspace ($8$)
-%     \item[\f] Form feed ($12$)
-%     \item[\(] Left parenthesis
-%     \item[\)] Right parenthesis
-%     \item[\\] Backslash
-%     \item[\ddd] (backslash followed by $1$ to $3$ octal digits) Byte
-%       \texttt{ddd} (octal), subtracting $256$ in case of overflow.
-%   \end{itemize}
-%   If followed by an end-of-line character, the backslash and the
-%   end-of-line are ignored. If followed by anything else, the backslash
-%   is ignored, raising the error flag.
-%^^A Be paranoid: \tl_to_lowercase:n is unsafe.
-%    \begin{macrocode}
-%<*string>
-\group_begin:
-  \char_set_lccode:nn {`\*} {`\\}
-  \char_set_catcode_other:N \^^J
-  \char_set_catcode_other:N \^^M
-  \tl_to_lowercase:n
-    {
-      \cs_new_protected_nopar:Npn \@@_convert_unescape_string:
-        {
-          \group_begin:
-            \flag_clear:n { str_byte }
-            \flag_clear:n { str_error }
-            \int_set:Nn \tex_escapechar:D { 92 }
-            \tl_gset:Nx \g_@@_result_tl
-              {
-                \exp_after:wN \@@_unescape_string_newlines:wN
-                  \g_@@_result_tl \__prg_break: ^^M ?
-                \__prg_break_point:
-              }
-            \tl_gset:Nx \g_@@_result_tl
-              {
-                \exp_after:wN \@@_unescape_string_loop:wNNN
-                  \g_@@_result_tl * ?? { ? \__prg_break: }
-                \__prg_break_point:
-              }
-            \@@_if_flag_error:nnx { str_byte } { non-byte } { string }
-            \@@_if_flag_error:nnx { str_error } { unescape-string } { }
-          \group_end:
-        }
-      \cs_new:Npn \@@_unescape_string_loop:wNNN #1 *#2#3#4
-    }
-        {
-          \@@_filter_bytes:n {#1}
-          \use_none:n #4
-          \@@_output_byte:w '
-            \@@_octal_use:NTF #2
-              {
-                \@@_octal_use:NTF #3
-                  {
-                    \@@_octal_use:NTF #4
-                      {
-                        \if_int_compare:w #2 > \c_three
-                          - 256
-                        \fi:
-                        \@@_unescape_string_repeat:NNNNNN
-                      }
-                      { \@@_unescape_string_repeat:NNNNNN ? }
-                  }
-                  { \@@_unescape_string_repeat:NNNNNN ?? }
-              }
-              {
-                \str_case_x:nnn {#2}
-                  {
-                    { \c_backslash_str } { 134 }
-                    { ( } { 50 }
-                    { ) } { 51 }
-                    { r } { 15 }
-                    { f } { 14 }
-                    { n } { 12 }
-                    { t } { 11 }
-                    { b } { 10 }
-                    { ^^J } { 0 - \c_one }
-                  }
-                  {
-                    \flag_raise:n { str_error }
-                    0 - \c_one \use_i:nn
-                  }
-              }
-          \@@_output_end:
-          \use_i:nn \@@_unescape_string_loop:wNNN #2#3#4
-        }
-  \cs_new:Npn \@@_unescape_string_repeat:NNNNNN #1#2#3#4#5#6
-    { \@@_output_end: \@@_unescape_string_loop:wNNN }
-  \cs_new:Npn \@@_unescape_string_newlines:wN #1 ^^M #2
-    {
-      #1
-      \if_charcode:w ^^J #2 \else: ^^J \fi:
-      \@@_unescape_string_newlines:wN #2
-    }
-  \__msg_kernel_new:nnnn { str } { unescape-string }
-    { String~invalid~in~escaping~'string'. }
-    {
-      LaTeX~came~across~an~escape~character~'\c_backslash_str'~
-      not~followed~by~any~of:~'n',~'r',~'t',~'b',~'f',~'(',~')',~
-      '\c_backslash_str',~one~to~three~octal~digits,~or~the~end~
-      of~a~line.
-    }
-\group_end:
-%</string>
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \subsubsection{Escape methods}
-%
-% Currently, none of the escape methods can lead to errors, assuming
-% that their input is made out of bytes.
-%
-% \begin{macro}[int]{\@@_convert_escape_hex:}
-% \begin{macro}[aux, rEXP]{\@@_escape_hex_char:N}
-%   Loop and convert each byte to hexadecimal.
-%    \begin{macrocode}
-%<*hex>
-\cs_new_protected_nopar:Npn \@@_convert_escape_hex:
-  { \@@_convert_gmap:N \@@_escape_hex_char:N }
-\cs_new:Npn \@@_escape_hex_char:N #1
-  { \@@_output_hexadecimal:n { `#1 } }
-%</hex>
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_escape_name:}
-% \begin{macro}[aux, rEXP]{\@@_escape_name_char:N}
-% \begin{macro}[aux, rEXP]{\@@_if_escape_name:NTF}
-% \begin{variable}{\c_@@_escape_name_str}
-% \begin{variable}{\c_@@_escape_name_not_str}
-%   For each byte, test whether it should be output as is, or be
-%   \enquote{hash-encoded}.  Roughly, bytes outside the range
-%   $[\hexnum{2A},\hexnum{7E}]$ are hash-encoded. We keep two lists of
-%   exceptions: characters in \cs{c_@@_escape_name_not_str} are not
-%   hash-encoded, and characters in the \cs{c_@@_escape_name_str} are
-%   encoded.
-%    \begin{macrocode}
-%<*name>
-\str_const:Nn \c_@@_escape_name_not_str { ! " $ & ' } %$
-\str_const:Nn \c_@@_escape_name_str { {}/<>[] }
-\cs_new_protected_nopar:Npn \@@_convert_escape_name:
-  { \@@_convert_gmap:N \@@_escape_name_char:N }
-\cs_new:Npn \@@_escape_name_char:N #1
-  {
-    \@@_if_escape_name:NTF #1 {#1}
-      { \c_hash_str \@@_output_hexadecimal:n {`#1} }
-  }
-\prg_new_conditional:Npnn \@@_if_escape_name:N #1 { TF }
-  {
-    \if_int_compare:w `#1 < "2A \exp_stop_f:
-      \@@_if_contains_char:NNTF \c_@@_escape_name_not_str #1
-        \prg_return_true: \prg_return_false:
-    \else:
-      \if_int_compare:w `#1 > "7E \exp_stop_f:
-        \prg_return_false:
-      \else:
-        \@@_if_contains_char:NNTF \c_@@_escape_name_str #1
-          \prg_return_false: \prg_return_true:
-      \fi:
-    \fi:
-  }
-%</name>
-%    \end{macrocode}
-% \end{variable}
-% \end{variable}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_escape_string:}
-% \begin{macro}[aux, rEXP]{\@@_escape_string_char:N}
-% \begin{macro}[aux, rEXP]{\@@_if_escape_string:NTF}
-% \begin{variable}{\c_@@_escape_string_str}
-%   Any character below (and including) space, and any character above
-%   (and including) \texttt{del}, are converted to octal.  One backslash
-%   is added before each parenthesis and backslash.
-%    \begin{macrocode}
-%<*string>
-\str_const:Nx \c_@@_escape_string_str
-  { \c_backslash_str ( ) }
-\cs_new_protected_nopar:Npn \@@_convert_escape_string:
-  { \@@_convert_gmap:N \@@_escape_string_char:N }
-\cs_new:Npn \@@_escape_string_char:N #1
-  {
-    \@@_if_escape_string:NTF #1
-      {
-        \@@_if_contains_char:NNT
-          \c_@@_escape_string_str #1
-          { \c_backslash_str }
-        #1
-      }
-      {
-        \c_backslash_str
-        \int_div_truncate:nn {`#1} {64}
-        \int_mod:nn { \int_div_truncate:nn {`#1} \c_eight } \c_eight
-        \int_mod:nn {`#1} \c_eight
-      }
-  }
-\prg_new_conditional:Npnn \@@_if_escape_string:N #1 { TF }
-  {
-    \if_int_compare:w `#1 < "21 \exp_stop_f:
-      \prg_return_false:
-    \else:
-      \if_int_compare:w `#1 > "7E \exp_stop_f:
-        \prg_return_false:
-      \else:
-        \prg_return_true:
-      \fi:
-    \fi:
-  }
-%</string>
-%    \end{macrocode}
-% \end{variable}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[int]{\@@_convert_escape_url:}
-% \begin{macro}[aux, rEXP]{\@@_escape_url_char:N}
-% \begin{macro}[aux, rEXP]{\@@_if_escape_url:NTF}
-%   This function is similar to \cs{@@_convert_escape_name:}, escaping
-%   different characters.
-%    \begin{macrocode}
-%<*url>
-\cs_new_protected_nopar:Npn \@@_convert_escape_url:
-  { \@@_convert_gmap:N \@@_escape_url_char:N }
-\cs_new:Npn \@@_escape_url_char:N #1
-  {
-    \@@_if_escape_url:NTF #1 {#1}
-      { \c_percent_str \@@_output_hexadecimal:n { `#1 } }
-  }
-\prg_new_conditional:Npnn \@@_if_escape_url:N #1 { TF }
-  {
-    \if_int_compare:w `#1 < "41 \exp_stop_f:
-      \@@_if_contains_char:nNTF { "-.<> } #1
-        \prg_return_true: \prg_return_false:
-    \else:
-      \if_int_compare:w `#1 > "7E \exp_stop_f:
-        \prg_return_false:
-      \else:
-        \@@_if_contains_char:nNTF { [ ] } #1
-          \prg_return_false: \prg_return_true:
-      \fi:
-    \fi:
-  }
-%</url>
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Encoding definition files}
-%
-% The \texttt{native} encoding is automatically defined. Other encodings
-% are loaded as needed. The following encodings are supported:
-% \begin{itemize}
-%   \item \textsc{utf-8};
-%   \item \textsc{utf-16}, big-, little-endian, or with byte order mark;
-%   \item \textsc{utf-32}, big-, little-endian, or with byte order mark;
-%   \item the \textsc{iso 8859} code pages, numbered from $1$ to $16$,
-%     skipping the inexistent \textsc{iso 8859-12}.
-% \end{itemize}
-%
-% \subsubsection{\textsc{utf-8} support}
-%
-%    \begin{macrocode}
-%<*utf8>
-%    \end{macrocode}
-%
-% \begin{macro}[int]{\@@_convert_encode_utf8:}
-% \begin{macro}[aux, rEXP]{\@@_encode_utf_viii_char:n}
-% \begin{macro}[aux, rEXP]{\@@_encode_utf_viii_loop:wwnnw}
-%   Loop through the internal string, and convert each character to its
-%   \textsc{utf-8} representation. The representation is built from the
-%   right-most (least significant) byte to the left-most (most
-%   significant) byte. Continuation bytes are in the range $[128,191]$,
-%   taking $64$ different values, hence we roughly want to express the
-%   character code in base $64$, shifting the first digit in the
-%   representation by some number depending on how many continuation
-%   bytes there are. In the range $[0,127]$, output the corresponding
-%   byte directly. In the range $[128,2047]$, output the remainder
-%   modulo $64$, plus $128$ as a continuation byte, then output the
-%   quotient (which is in the range $[0,31]$), shifted by $192$. In the
-%   next range, $[2048,65535]$, split the character code into residue
-%   and quotient modulo $64$, output the residue as a first continuation
-%   byte, then repeat; this leaves us with a quotient in the range
-%   $[0,15]$, which we output shifted by $224$. The last range,
-%   $[65536,1114111]$, follows the same pattern: once we realize that
-%   dividing twice by $64$ leaves us with a number larger than $15$, we
-%   repeat, producing a last continuation byte, and offset the quotient
-%   by $240$ for the leading byte.
-%
-%   How is that implemented? \cs{@@_encode_utf_vii_loop:wwnnw} takes
-%   successive quotients as its first argument, the quotient from the
-%   previous step as its second argument (except in step~$1$), the bound
-%   for quotients that trigger one more step or not, and finally the
-%   offset used if this step should produce the leading byte. Leading
-%   bytes can be in the ranges $[0,127]$, $[192,223]$, $[224,239]$, and
-%   $[240,247]$ (really, that last limit should be $244$ because Unicode
-%   stops at the code point $1114111$). At each step, if the quotient
-%   |#1| is less than the limit |#3| for that range, output the leading
-%   byte (|#1| shifted by |#4|) and stop. Otherwise, we need one more
-%   step: use the quotient of |#1| by $64$, and |#1| as arguments for
-%   the looping auxiliary, and output the continuation byte
-%   corresponding to the remainder $|#2|-64|#1|+128$. The bizarre
-%   construction |\c_minus_one + \c_zero *| removes the spurious initial
-%   continuation byte (better methods welcome).
-%    \begin{macrocode}
-\cs_new_protected_nopar:cpn { @@_convert_encode_utf8: }
-  { \@@_convert_gmap_internal:N \@@_encode_utf_viii_char:n }
-\cs_new:Npn \@@_encode_utf_viii_char:n #1
-  {
-    \@@_encode_utf_viii_loop:wwnnw #1 ; \c_minus_one + \c_zero * ;
-      { 128 } { \c_zero }
-      {  32 } {     192 }
-      {  16 } {     224 }
-      {   8 } {     240 }
-    \q_stop
-  }
-\cs_new:Npn \@@_encode_utf_viii_loop:wwnnw #1; #2; #3#4 #5 \q_stop
-  {
-    \if_int_compare:w #1 < #3 \exp_stop_f:
-      \@@_output_byte:n { #1 + #4 }
-      \exp_after:wN \use_none_delimit_by_q_stop:w
-    \fi:
-    \exp_after:wN \@@_encode_utf_viii_loop:wwnnw
-      \__int_value:w \int_div_truncate:nn {#1} {64} ; #1 ;
-      #5 \q_stop
-    \@@_output_byte:n { #2 - 64 * ( #1 - \c_two ) }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{variable}
-%   {
-%     \l_@@_missing_flag  ,
-%     \l_@@_extra_flag    ,
-%     \l_@@_overlong_flag ,
-%     \l_@@_overflow_flag ,
-%   }
-%   When decoding a string that is purportedly in the \textsc{utf-8}
-%   encoding, four different errors can occur, signalled by a specific
-%   flag for each (we define those flags using \cs{flag_clear_new:n}
-%   rather than \cs{flag_new:n}, because they are shared with other
-%   encoding definition files).
-%   \begin{itemize}
-%     \item \enquote{Missing continuation byte}: a leading byte is not
-%       followed by the right number of continuation bytes.
-%     \item \enquote{Extra continuation byte}: a continuation byte
-%       appears where it was not expected, \emph{i.e.}, not after an
-%       appropriate leading byte.
-%     \item \enquote{Overlong}: a Unicode character is expressed using
-%       more bytes than necessary, for instance, \hexnum{C0}\hexnum{80}
-%       for the code point $0$, instead of a single null byte.
-%     \item \enquote{Overflow}: this occurs when decoding produces
-%       Unicode code points greater than $1114111$.
-%   \end{itemize}
-%   We only raise one \LaTeX3 error message, combining all the errors
-%   which occurred. In the short message, the leading comma must be
-%   removed to get a grammatically correct sentence. In the long text,
-%   first remind the user what a correct \textsc{utf-8} string should
-%   look like, then add error-specific information.
-%    \begin{macrocode}
-\flag_clear_new:n { str_missing }
-\flag_clear_new:n { str_extra }
-\flag_clear_new:n { str_overlong }
-\flag_clear_new:n { str_overflow }
-\__msg_kernel_new:nnnn { str } { utf8-decode }
-  {
-    Invalid~UTF-8~string: \exp_last_unbraced:Nf \use_none:n
-    \@@_if_flag_times:nT { str_missing }  { ,~missing~continuation~byte }
-    \@@_if_flag_times:nT { str_extra }    { ,~extra~continuation~byte }
-    \@@_if_flag_times:nT { str_overlong } { ,~overlong~form }
-    \@@_if_flag_times:nT { str_overflow } { ,~code~point~too~large }
-    .
-  }
-  {
-    In~the~UTF-8~encoding,~each~Unicode~character~consists~in~
-    1~to~4~bytes,~with~the~following~bit~pattern: \\
-    \iow_indent:n
-      {
-        Code~point~\ \ \ \ <~128:~0xxxxxxx \\
-        Code~point~\ \ \  <~2048:~110xxxxx~10xxxxxx \\
-        Code~point~\ \   <~65536:~1110xxxx~10xxxxxx~10xxxxxx \\
-        Code~point~    <~1114112:~11110xxx~10xxxxxx~10xxxxxx~10xxxxxx \\
-      }
-    Bytes~of~the~form~10xxxxxx~are~called~continuation~bytes.
-    \flag_if_raised:nT { str_missing }
-      {
-        \\\\
-        A~leading~byte~(in~the~range~[192,255])~was~not~followed~by~
-        the~appropriate~number~of~continuation~bytes.
-      }
-    \flag_if_raised:nT { str_extra }
-      {
-        \\\\
-        LaTeX~came~across~a~continuation~byte~when~it~was~not~expected.
-      }
-    \flag_if_raised:nT { str_overlong }
-      {
-        \\\\
-        Every~Unicode~code~point~must~be~expressed~in~the~shortest~
-        possible~form.~For~instance,~'0xC0'~'0x83'~is~not~a~valid~
-        representation~for~the~code~point~3.
-      }
-    \flag_if_raised:nT { str_overflow }
-      {
-        \\\\
-        Unicode~limits~code~points~to~the~range~[0,1114111].
-      }
-  }
-%    \end{macrocode}
-% \end{variable}
 %
-% \begin{macro}[int]{\@@_convert_decode_utf8:}
-% \begin{macro}[aux, rEXP]
-%   {
-%     \@@_decode_utf_viii_start:N,
-%     \@@_decode_utf_viii_continuation:wwN,
-%     \@@_decode_utf_viii_aux:wNnnwN
-%   }
-% \begin{macro}[aux, rEXP]
-%   {\@@_decode_utf_viii_overflow:w, \@@_decode_utf_viii_end:}
-%   Decoding is significantly harder than encoding. As before, lower
-%   some flags, which are tested at the end (in bulk, to trigger at most
-%   one \LaTeX3 error, as explained above). We expect successive
-%   multi-byte sequences of the form \meta{start byte}
-%   \meta{continuation bytes}. The \texttt{_start} auxiliary tests the
-%   first byte:
-%   \begin{itemize}
-%     \item $[0,\hexnum{7F}]$: the byte stands alone, and is converted
-%       to its own character code;
-%     \item $[\hexnum{80}, \hexnum{BF}]$: unexpected continuation byte,
-%       raise the appropriate flag, and convert that byte to the
-%       replacement character \hexnum{FFFD};
-%     \item $[\hexnum{C0}, \hexnum{FF}]$: this byte should be followed
-%       by some continuation byte(s).
-%   \end{itemize}
-%   In the first two cases, \cs{use_none_delimit_by_q_stop:w} removes
-%   data that only the third case requires, namely the limits of ranges
-%   of Unicode characters which can be expressed with $1$, $2$, $3$, or
-%   $4$ bytes.
-%
-%   We can now concentrate on the multi-byte case and the
-%   \texttt{_continuation} auxiliary. We expect |#3| to be in the range
-%   $[\hexnum{80}, \hexnum{BF}]$. The test for this goes as follows: if
-%   the character code is less than \hexnum{80}, we compare it to
-%   $-\hexnum{C0}$, yielding \texttt{false}; otherwise to \hexnum{C0},
-%   yielding \texttt{true} in the range $[\hexnum{80}, \hexnum{BF}]$ and
-%   \texttt{false} otherwise. If we find that the byte is not a
-%   continuation range, stop the current slew of bytes, output the
-%   replacement character, and continue parsing with the \texttt{_start}
-%   auxiliary, starting at the byte we just tested. Once we know that
-%   the byte is a continuation byte, leave it behind us in the input
-%   stream, compute what code point the bytes read so far would produce,
-%   and feed that number to the \texttt{_aux} function.
-%
-%   The \texttt{_aux} function tests whether we should look for more
-%   continuation bytes or not. If the number it receives as |#1| is less
-%   than the maximum |#4| for the current range, then we are done: check
-%   for an overlong representation by comparing |#1| with the maximum
-%   |#3| for the previous range. Otherwise, we call the
-%   \texttt{_continuation} auxiliary again, after shifting the
-%   \enquote{current code point} by |#4| (maximum from the range we just
-%   checkedd).
-%
-%   Two additional tests are needed: if we reach the end of the list of
-%   range maxima and we are still not done, then we are faced with an
-%   overflow. Clean up, and again insert the code point \hexnum{FFFD}
-%   for the replacement character. Also, every time we read a byte, we
-%   need to check whether we reached the end of the string. In a correct
-%   \textsc{utf-8} string, this happens automatically when the
-%   \texttt{_start} auxiliary leaves its first argument in the input
-%   stream: the end-marker begins with \cs{__prg_break:}, which ends
-%   the loop. On the other hand, if the end is reached when looking for
-%   a continuation byte, the \cs{use_none:n} |#3| construction removes
-%   the first token from the end-marker, and leaves the \texttt{_end}
-%   auxiliary, which raises the appropriate error flag before ending the
-%   mapping.
-%    \begin{macrocode}
-\cs_new_protected_nopar:cpn { @@_convert_decode_utf8: }
-  {
-    \flag_clear:n { str_error }
-    \flag_clear:n { str_missing }
-    \flag_clear:n { str_extra }
-    \flag_clear:n { str_overlong }
-    \flag_clear:n { str_overflow }
-    \tl_gset:Nx \g_@@_result_tl
-      {
-        \exp_after:wN \@@_decode_utf_viii_start:N \g_@@_result_tl
-          { \__prg_break: \@@_decode_utf_viii_end: }
-        \__prg_break_point:
-      }
-    \@@_if_flag_error:nnx { str_error } { utf8-decode } { }
-  }
-\cs_new:Npn \@@_decode_utf_viii_start:N #1
-  {
-    #1
-    \if_int_compare:w `#1 < "C0 \exp_stop_f:
-      \s__tl
-      \if_int_compare:w `#1 < "80 \exp_stop_f:
-        \__int_value:w `#1
-      \else:
-        \flag_raise:n { str_extra }
-        \flag_raise:n { str_error }
-        \int_use:N \c_@@_replacement_char_int
-      \fi:
-    \else:
-      \exp_after:wN \@@_decode_utf_viii_continuation:wwN
-      \int_use:N \__int_eval:w `#1 - "C0 \exp_after:wN \__int_eval_end:
-    \fi:
-    \s__tl
-    \use_none_delimit_by_q_stop:w {"80} {"800} {"10000} {"110000} \q_stop
-    \@@_decode_utf_viii_start:N
-  }
-\cs_new:Npn \@@_decode_utf_viii_continuation:wwN
-    #1 \s__tl #2 \@@_decode_utf_viii_start:N #3
-  {
-    \use_none:n #3
-    \if_int_compare:w `#3 <
-          \if_int_compare:w `#3 < "80 \exp_stop_f: - \fi:
-          "C0 \exp_stop_f:
-      #3
-      \exp_after:wN \@@_decode_utf_viii_aux:wNnnwN
-      \int_use:N \__int_eval:w
-        #1 * "40 + `#3 - "80
-      \exp_after:wN \__int_eval_end:
-    \else:
-      \s__tl
-      \flag_raise:n { str_missing }
-      \flag_raise:n { str_error }
-      \int_use:N \c_@@_replacement_char_int
-    \fi:
-    \s__tl
-    #2
-    \@@_decode_utf_viii_start:N #3
-  }
-\cs_new:Npn \@@_decode_utf_viii_aux:wNnnwN
-    #1 \s__tl #2#3#4 #5 \@@_decode_utf_viii_start:N #6
-  {
-    \if_int_compare:w #1 < #4 \exp_stop_f:
-      \s__tl
-      \if_int_compare:w #1 < #3 \exp_stop_f:
-        \flag_raise:n { str_overlong }
-        \flag_raise:n { str_error }
-        \int_use:N \c_@@_replacement_char_int
-      \else:
-        #1
-      \fi:
-    \else:
-      \if_meaning:w \q_stop #5
-        \@@_decode_utf_viii_overflow:w #1
-      \fi:
-      \exp_after:wN \@@_decode_utf_viii_continuation:wwN
-      \int_use:N \__int_eval:w #1 - #4 \exp_after:wN \__int_eval_end:
-    \fi:
-    \s__tl
-    #2 {#4} #5
-    \@@_decode_utf_viii_start:N
-  }
-\cs_new:Npn \@@_decode_utf_viii_overflow:w #1 \fi: #2 \fi:
-  {
-    \fi: \fi:
-    \flag_raise:n { str_overflow }
-    \flag_raise:n { str_error }
-    \int_use:N \c_@@_replacement_char_int
-  }
-\cs_new_nopar:Npn \@@_decode_utf_viii_end:
+% Deprecated 2013-01-20 for removal by 2013-04-30
+% \begin{macro}[EXP]
+%   {\str_substr:Nnn, \str_substr:nnn, \str_substr_ignore_spaces:nnn}
+% \begin{macro}[EXP, aux]{\@@_substr:nnn}
+%   These functions used to allow for an empty argument to denote the
+%   start/end of the string.  We reimplement them here by first checking
+%   for an empty argument, then only calling the appropriate version of
+%   the \cs{str_range:nnn} function.
+%    \begin{macrocode}
+\cs_new:Npn \str_substr:Nnn #1 { \@@_substr:nnn { \str_range:Nnn #1 } }
+\cs_new:Npn \str_substr:nnn #1 { \@@_substr:nnn { \str_range:nnn {#1} } }
+\cs_new:Npn \str_substr_ignore_spaces:nnn #1
+  { \@@_substr:nnn { \str_range_ignore_spaces:nnn {#1} } }
+\cs_new:Npn \@@_substr:nnn #1#2#3
   {
-    \s__tl
-    \flag_raise:n { str_missing }
-    \flag_raise:n { str_error }
-    \int_use:N \c_@@_replacement_char_int \s__tl
-    \__prg_break:
+    \tl_if_empty:nTF {#2}
+      { \tl_if_empty:nTF {#3} { #1 { 1} { -1 } } { #1 { 1} {#3} } }
+      { \tl_if_empty:nTF {#3} { #1 {#2} { -1 } } { #1 {#2} {#3} } }
   }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
+% Deprecated 2013-01-20 for removal by 2013-04-30
+% \begin{variable}{\c_lbrace_str, \c_rbrace_str}
 %    \begin{macrocode}
-%</utf8>
-%    \end{macrocode}
-%
-% \subsubsection{\textsc{utf-16} support}
-%
-% The definitions are done in a category code regime where the bytes
-% $254$ and $255$ used by the byte order mark have catcode~$12$.
-%    \begin{macrocode}
-%<*utf16>
-\group_begin:
-  \char_set_catcode_other:N \^^fe
-  \char_set_catcode_other:N \^^ff
-%    \end{macrocode}
-%
-% \begin{macro}[int]
-%   {
-%     \@@_convert_encode_utf16:   ,
-%     \@@_convert_encode_utf16be: ,
-%     \@@_convert_encode_utf16le: ,
-%   }
-% \begin{macro}[aux, rEXP]
-%   {
-%     \@@_encode_utf_xvi_aux:N  ,
-%     \@@_encode_utf_xvi_char:n ,
-%   }
-%   When the endianness is not specified, it is big-endian by default,
-%   and we add a byte-order mark.  Convert characters one by one in a
-%   loop, with different behaviours depending on the character code.
-%   \begin{itemize}
-%     \item $[0, \hexnum{D7FF}]$: converted to two bytes;
-%     \item $[\hexnum{D800}, \hexnum{DFFF}]$ are used as surrogates:
-%       they cannot be converted and are replaced by the replacement
-%       character;
-%     \item $[\hexnum{E000}, \hexnum{FFFF}]$: converted to two bytes;
-%     \item $[\hexnum{10000}, \hexnum{10FFFF}]$: converted to a pair of
-%       surrogates, each two bytes. The magic \hexnum{D7C0} is
-%       $\hexnum{D800}-\hexnum{10000}/\hexnum{400}$.
-%   \end{itemize}
-%   For the duration of this operation, \cs{@@_tmp:w} is defined as a
-%   function to convert a number in the range $[0, \hexnum{FFFF}]$ to a
-%   pair of bytes (either big endian or little endian), by feeding the
-%   quotient of the division of |#1| by \hexnum{100}, followed by |#1|
-%   to \cs{@@_encode_utf_xvi_be:nn} or its \texttt{le} analog: those
-%   compute the remainder, and output two bytes for the quotient and
-%   remainder.
-%    \begin{macrocode}
-  \cs_new_protected_nopar:cpn { @@_convert_encode_utf16: }
-    {
-      \@@_encode_utf_xvi_aux:N \@@_output_byte_pair_be:n
-      \tl_gput_left:Nx \g_@@_result_tl { ^^fe ^^ff }
-    }
-  \cs_new_protected_nopar:cpn { @@_convert_encode_utf16be: }
-    { \@@_encode_utf_xvi_aux:N \@@_output_byte_pair_be:n }
-  \cs_new_protected_nopar:cpn { @@_convert_encode_utf16le: }
-    { \@@_encode_utf_xvi_aux:N \@@_output_byte_pair_le:n }
-  \cs_new_protected:Npn \@@_encode_utf_xvi_aux:N #1
-    {
-      \flag_clear:n { str_error }
-      \cs_set_eq:NN \@@_tmp:w #1
-      \@@_convert_gmap_internal:N \@@_encode_utf_xvi_char:n
-      \@@_if_flag_error:nnx { str_error } { utf16-encode } { }
-    }
-  \cs_new:Npn \@@_encode_utf_xvi_char:n #1
-    {
-      \if_int_compare:w #1 < "D800 \exp_stop_f:
-        \@@_tmp:w {#1}
-      \else:
-        \if_int_compare:w #1 < "10000 \exp_stop_f:
-          \if_int_compare:w #1 < "E000 \exp_stop_f:
-            \flag_raise:n { str_error }
-            \@@_tmp:w { \c_@@_replacement_char_int }
-          \else:
-            \@@_tmp:w {#1}
-          \fi:
-        \else:
-          \exp_args:Nf \@@_tmp:w { \int_div_truncate:nn {#1} {"400} + "D7C0 }
-          \exp_args:Nf \@@_tmp:w { \int_mod:nn {#1} {"400} + "DC00 }
-        \fi:
-      \fi:
-    }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{variable}
-%   {
-%     \l_@@_missing_flag ,
-%     \l_@@_extra_flag   ,
-%     \l_@@_end_flag     ,
-%   }
-%   When encoding a Unicode string to \textsc{utf-16}, only one error
-%   can occur: code points in the range $[\hexnum{D800},
-%   \hexnum{DFFF}]$, corresponding to surrogates, cannot be encoded. We
-%   use the all-purpose flag \texttt{@@_error} to signal that error.
-%
-%   When decoding a Unicode string which is purportedly in
-%   \textsc{utf-16}, three errors can occur: a missing trail surrogate,
-%   an unexpected trail surrogate, and a string containing an odd number
-%   of bytes.
-%    \begin{macrocode}
-  \flag_clear_new:n { str_missing }
-  \flag_clear_new:n { str_extra }
-  \flag_clear_new:n { str_end }
-  \__msg_kernel_new:nnnn { str } { utf16-encode }
-    { Unicode~string~cannot~be~expressed~in~UTF-16:~surrogate. }
-    {
-      Surrogate~code~points~(in~the~range~[U+D800,~U+DFFF])~
-      can~be~expressed~in~the~UTF-8~and~UTF-32~encodings,~
-      but~not~in~the~UTF-16~encoding.
-    }
-  \__msg_kernel_new:nnnn { str } { utf16-decode }
-    {
-      Invalid~UTF-16~string: \exp_last_unbraced:Nf \use_none:n
-      \@@_if_flag_times:nT { str_missing }  { ,~missing~trail~surrogate }
-      \@@_if_flag_times:nT { str_extra }    { ,~extra~trail~surrogate }
-      \@@_if_flag_times:nT { str_end }      { ,~odd~number~of~bytes }
-      .
-    }
-    {
-      In~the~UTF-16~encoding,~each~Unicode~character~is~encoded~as~
-      2~or~4~bytes: \\
-      \iow_indent:n
-        {
-          Code~point~in~[U+0000,~U+D7FF]:~two~bytes \\
-          Code~point~in~[U+D800,~U+DFFF]:~illegal \\
-          Code~point~in~[U+E000,~U+FFFF]:~two~bytes \\
-          Code~point~in~[U+10000,~U+10FFFF]:~
-            a~lead~surrogate~and~a~trail~surrogate \\
-        }
-      Lead~surrogates~are~pairs~of~bytes~in~the~range~[0xD800,~0xDBFF],~
-      and~trail~surrogates~are~in~the~range~[0xDC00,~0xDFFF].
-      \flag_if_raised:nT { str_missing }
-        {
-          \\\\
-          A~lead~surrogate~was~not~followed~by~a~trail~surrogate.
-        }
-      \flag_if_raised:nT { str_extra }
-        {
-          \\\\
-          LaTeX~came~across~a~trail~surrogate~when~it~was~not~expected.
-        }
-      \flag_if_raised:nT { str_end }
-        {
-          \\\\
-          The~string~contained~an~odd~number~of~bytes.~This~is~invalid:~
-          the~basic~code~unit~for~UTF-16~is~16~bits~(2~bytes).
-        }
-    }
+\cs_new_eq:NN \c_lbrace_str \c_left_brace_str
+\cs_new_eq:NN \c_rbrace_str \c_right_brace_str
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{macro}[int]
-%   {
-%     \@@_convert_decode_utf16:   ,
-%     \@@_convert_decode_utf16be: ,
-%     \@@_convert_decode_utf16le: ,
-%   }
-% \begin{macro}[aux]{\@@_decode_utf_xvi_bom:NN, \@@_decode_utf_xvi:Nw}
-%   As for \textsc{utf-8}, decoding \textsc{utf-16} is harder than
-%   encoding it. If the endianness is unknown, check the first two
-%   bytes: if those are \hexnum{FE} and \hexnum{FF} in either order,
-%   remove them and use the corresponding endianness, otherwise assume
-%   big-endianness. The three endianness cases are based on a common
-%   auxiliary whose first argument is $1$ for big-endian and $2$ for
-%   little-endian, and whose second argument, delimited by the scan mark
-%   \cs{s__stop}, is expanded once (the string may be long; passing
-%   \cs{g_@@_result_tl} as an argument before expansion is cheaper).
-%
-%   The \cs{@@_decode_utf_xvi:Nw} function defines \cs{@@_tmp:w} to
-%   take two arguments and return the character code of the first one if
-%   the string is big-endian, and the second one if the string is
-%   little-endian, then loops over the string using
-%   \cs{@@_decode_utf_xvi_pair:NN} described below.
-%    \begin{macrocode}
-  \cs_new_protected_nopar:cpn { @@_convert_decode_utf16be: }
-    { \@@_decode_utf_xvi:Nw 1 \g_@@_result_tl \s__stop }
-  \cs_new_protected_nopar:cpn { @@_convert_decode_utf16le: }
-    { \@@_decode_utf_xvi:Nw 2 \g_@@_result_tl \s__stop }
-  \cs_new_protected_nopar:cpn { @@_convert_decode_utf16: }
-    {
-      \exp_after:wN \@@_decode_utf_xvi_bom:NN
-        \g_@@_result_tl \s__stop \s__stop \s__stop
-    }
-  \cs_new_protected:Npn \@@_decode_utf_xvi_bom:NN #1#2
-    {
-      \str_if_eq_x:nnTF { #1#2 } { ^^ff ^^fe }
-        { \@@_decode_utf_xvi:Nw 2 }
-        {
-          \str_if_eq_x:nnTF { #1#2 } { ^^fe ^^ff }
-            { \@@_decode_utf_xvi:Nw 1 }
-            { \@@_decode_utf_xvi:Nw 1 #1#2 }
-        }
-    }
-  \cs_new_protected:Npn \@@_decode_utf_xvi:Nw #1#2 \s__stop
-    {
-      \flag_clear:n { str_error }
-      \flag_clear:n { str_missing }
-      \flag_clear:n { str_extra }
-      \flag_clear:n { str_end }
-      \cs_set:Npn \@@_tmp:w ##1 ##2 { ` ## #1 }
-      \tl_gset:Nx \g_@@_result_tl
-        {
-          \exp_after:wN \@@_decode_utf_xvi_pair:NN
-            #2 \q_nil \q_nil
-          \__prg_break_point:
-        }
-      \@@_if_flag_error:nnx { str_error } { utf16-decode } { }
-    }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[aux, rEXP]
-%   {
-%     \@@_decode_utf_xvi_pair:NN     ,
-%     \@@_decode_utf_xvi_quad:NNwNN  ,
-%     \@@_decode_utf_xvi_pair_end:Nw ,
-%   }
-% \begin{macro}[aux, rEXP]
-%   {
-%     \@@_decode_utf_xvi_error:nNN ,
-%     \@@_decode_utf_xvi_extra:NNw ,
-%   }
-%   Bytes are read two at a time. At this stage, |\@@_tmp:w #1#2|
-%   expands to the character code of the most significant byte, and we
-%   distinguish cases depending on which range it lies in:
-%   \begin{itemize}
-%     \item $[\hexnum{D8}, \hexnum{DB}]$ signals a lead surrogate, and
-%       the integer expression yields $1$ (\eTeX{} rounds ties away from
-%       zero);
-%     \item $[\hexnum{DC}, \hexnum{DF}]$ signals a trail surrogate,
-%       unexpected here, and the integer expression yields $2$;
-%     \item any other value signals a code point in the Basic
-%       Multilingual Plane, which stands for itself, and the
-%       \cs{if_case:w} construction expands to nothing (cases other than
-%       $1$ or $2$), leaving the relevant material in the input stream,
-%       followed by another call to the \texttt{_pair} auxiliary.
-%   \end{itemize}
-%   The case of a lead surrogate is treated by the \texttt{_quad}
-%   auxiliary, whose arguments |#1|, |#2|, |#4| and |#5| are the four
-%   bytes. We expect the most significant byte of |#4#5| to be in the
-%   range $[\hexnum{DC}, \hexnum{DF}]$ (trail surrogate). The test is
-%   similar to the test used for continuation bytes in the
-%   \textsc{utf-8} decoding functions. In the case where |#4#5| is
-%   indeed a trail surrogate, leave |#1#2#4#5| \cs{s__tl}
-%   \meta{code~point} \cs{s__tl}, and remove the pair |#4#5| before
-%   looping with \cs{@@_decode_utf_xvi_pair:NN}. Otherwise, of course,
-%   complain about the missing surrogate.
-%
-%   The magic number \hexnum{D7F7} is such that
-%   $\hexnum{D7F7}*\hexnum{400} = \hexnum{D800}*\hexnum{400} +
-%   \hexnum{DC00} - \hexnum{10000}$.
-%
-%   Every time we read a pair of bytes, we test for the end-marker
-%   \cs{q_nil}. When reaching the end, we additionally check that the
-%   string had an even length. Also, if the end is reached when
-%   expecting a trail surrogate, we treat that as a missing surrogate.
-%    \begin{macrocode}
-  \cs_new:Npn \@@_decode_utf_xvi_pair:NN #1#2
-    {
-      \if_meaning:w \q_nil #2
-        \@@_decode_utf_xvi_pair_end:Nw #1
-      \fi:
-      \if_case:w
-        \__int_eval:w ( \@@_tmp:w #1#2 - "D6 ) / \c_four \__int_eval_end:
-      \or: \exp_after:wN \@@_decode_utf_xvi_quad:NNwNN
-      \or: \exp_after:wN \@@_decode_utf_xvi_extra:NNw
-      \fi:
-      #1#2 \s__tl
-      \int_eval:n { "100 * \@@_tmp:w #1#2 + \@@_tmp:w #2#1 } \s__tl
-      \@@_decode_utf_xvi_pair:NN
-    }
-  \cs_new:Npn \@@_decode_utf_xvi_quad:NNwNN
-      #1#2 #3 \@@_decode_utf_xvi_pair:NN #4#5
-    {
-      \if_meaning:w \q_nil #5
-        \@@_decode_utf_xvi_error:nNN { missing } #1#2
-        \@@_decode_utf_xvi_pair_end:Nw #4
-      \fi:
-      \if_int_compare:w
-          \if_int_compare:w \@@_tmp:w #4#5 < "DC \exp_stop_f:
-            \c_zero = \c_one
-          \else:
-            \@@_tmp:w #4#5 < "E0 \exp_stop_f:
-          \fi:
-        #1 #2 #4 #5 \s__tl
-        \int_eval:n
-          {
-            ( "100 * \@@_tmp:w #1#2 + \@@_tmp:w #2#1 - "D7F7 ) * "400
-            + "100 * \@@_tmp:w #4#5 + \@@_tmp:w #5#4
-          }
-        \s__tl
-        \exp_after:wN \use_i:nnn
-      \else:
-        \@@_decode_utf_xvi_error:nNN { missing } #1#2
-      \fi:
-      \@@_decode_utf_xvi_pair:NN #4#5
-    }
-  \cs_new:Npn \@@_decode_utf_xvi_pair_end:Nw #1 \fi:
-    {
-      \fi:
-      \if_meaning:w \q_nil #1
-      \else:
-        \@@_decode_utf_xvi_error:nNN { end } #1 \prg_do_nothing:
-      \fi:
-      \__prg_break:
-    }
-  \cs_new:Npn \@@_decode_utf_xvi_extra:NNw #1#2 \s__tl #3 \s__tl
-    { \@@_decode_utf_xvi_error:nNN { extra } #1#2 }
-  \cs_new:Npn \@@_decode_utf_xvi_error:nNN #1#2#3
-    {
-      \flag_raise:n { str_error }
-      \flag_raise:n { str_#1 }
-      #2 #3 \s__tl
-      \int_use:N \c_@@_replacement_char_int \s__tl
-    }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% Restore the original catcodes of bytes $254$ and $255$.
-%    \begin{macrocode}
-\group_end:
-%</utf16>
-%    \end{macrocode}
-%
-% \subsubsection{\textsc{utf-32} support}
-%
-% The definitions are done in a category code regime where the bytes
-% $0$, $254$ and $255$ used by the byte order mark have catcode
-% \enquote{other}.
-%    \begin{macrocode}
-%<*utf32>
-\group_begin:
-  \char_set_catcode_other:N \^^00
-  \char_set_catcode_other:N \^^fe
-  \char_set_catcode_other:N \^^ff
-%    \end{macrocode}
-%
-% \begin{macro}[int]
-%   {
-%     \@@_convert_encode_utf32:   ,
-%     \@@_convert_encode_utf32be: ,
-%     \@@_convert_encode_utf32le: ,
-%   }
-% \begin{macro}[aux, rEXP]
-%   {
-%     \@@_encode_utf_xxxii_be:n      ,
-%     \@@_encode_utf_xxxii_be_aux:nn ,
-%     \@@_encode_utf_xxxii_le:n      ,
-%     \@@_encode_utf_xxxii_le_aux:nn ,
-%   }
-%   Convert each integer in the comma-list \cs{g_@@_result_tl} to a
-%   sequence of four bytes. The functions for big-endian and
-%   little-endian encodings are very similar, but the
-%   \cs{@@_output_byte:n} instructions are reversed.
-%    \begin{macrocode}
-  \cs_new_protected_nopar:cpn { @@_convert_encode_utf32: }
-    {
-      \@@_convert_gmap_internal:N \@@_encode_utf_xxxii_be:n
-      \tl_gput_left:Nx \g_@@_result_tl { ^^00 ^^00 ^^fe ^^ff }
-    }
-  \cs_new_protected_nopar:cpn { @@_convert_encode_utf32be: }
-    { \@@_convert_gmap_internal:N \@@_encode_utf_xxxii_be:n }
-  \cs_new_protected_nopar:cpn { @@_convert_encode_utf32le: }
-    { \@@_convert_gmap_internal:N \@@_encode_utf_xxxii_le:n }
-  \cs_new:Npn \@@_encode_utf_xxxii_be:n #1
-    {
-      \exp_args:Nf \@@_encode_utf_xxxii_be_aux:nn
-        { \int_div_truncate:nn {#1} { "100 } } {#1}
-    }
-  \cs_new:Npn \@@_encode_utf_xxxii_be_aux:nn #1#2
-    {
-      ^^00
-      \@@_output_byte_pair_be:n {#1}
-      \@@_output_byte:n { #2 - #1 * "100 }
-    }
-  \cs_new:Npn \@@_encode_utf_xxxii_le:n #1
-    {
-      \exp_args:Nf \@@_encode_utf_xxxii_le_aux:nn
-        { \int_div_truncate:nn {#1} { "100 } } {#1}
-    }
-  \cs_new:Npn \@@_encode_utf_xxxii_le_aux:nn #1#2
-    {
-      \@@_output_byte:n { #2 - #1 * "100 }
-      \@@_output_byte_pair_le:n {#1}
-      ^^00
-    }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{variable}{str_overflow, str_end}
-%   There can be no error when encoding in \textsc{utf-32}. When
-%   decoding, the string may not have length $4n$, or it may contain
-%   code points larger than \hexnum{10FFFF}. The latter case often
-%   happens if the encoding was in fact not \textsc{utf-32}, because
-%   most arbitrary strings are not valid in \textsc{utf-32}.
-%    \begin{macrocode}
-  \flag_clear_new:n { str_overflow }
-  \flag_clear_new:n { str_end }
-  \__msg_kernel_new:nnnn { str } { utf32-decode }
-    {
-      Invalid~UTF-32~string: \exp_last_unbraced:Nf \use_none:n
-      \@@_if_flag_times:nT { str_overflow } { ,~code~point~too~large }
-      \@@_if_flag_times:nT { str_end }      { ,~truncated~string }
-      .
-    }
-    {
-      In~the~UTF-32~encoding,~every~Unicode~character~
-      (in~the~range~[U+0000,~U+10FFFF])~is~encoded~as~4~bytes.
-      \flag_if_raised:nT { str_overflow }
-        {
-          \\\\
-          LaTeX~came~across~a~code~point~larger~than~1114111,~
-          the~maximum~code~point~defined~by~Unicode.~
-          Perhaps~the~string~was~not~encoded~in~the~UTF-32~encoding?
-        }
-      \flag_if_raised:nT { str_end }
-        {
-          \\\\
-          The~length~of~the~string~is~not~a~multiple~of~4.~
-          Perhaps~the~string~was~truncated?
-        }
-    }
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{macro}[int]
-%   {
-%     \@@_convert_decode_utf32:   ,
-%     \@@_convert_decode_utf32be: ,
-%     \@@_convert_decode_utf32le: ,
-%   }
-% \begin{macro}[aux]
-%   {\@@_decode_utf_xxxii_bom:NNNN, \@@_decode_utf_xxxii:Nw}
-% \begin{macro}[aux, rEXP]
-%   {\@@_decode_utf_xxxii_loop:NNNN, \@@_decode_utf_xxxii_end:w}
-%
-%   The structure is similar to \textsc{utf-16} decoding functions. If
-%   the endianness is not given, test the first $4$ bytes of the string
-%   (possibly \cs{s__stop} if the string is too short) for the presence
-%   of a byte-order mark. If there is a byte-order mark, use that
-%   endianness, and remove the $4$ bytes, otherwise default to
-%   big-endian, and leave the $4$ bytes in place. The
-%   \cs{@@_decode_utf_xxxii:Nw} auxiliary recieves $1$ or $2$ as its
-%   first argument indicating endianness, and the string to convert as
-%   its second argument (expanded or not). It sets \cs{@@_tmp:w} to
-%   expand to the character code of either of its two arguments
-%   depending on endianness, then triggers the \texttt{_loop} auxiliary
-%   inside an \texttt{x}-expanding assignment to \cs{g_@@_result_tl}.
-%
-%   The \texttt{_loop} auxiliary first checks for the end-of-string
-%   marker \cs{s__stop}, calling the \texttt{_end} auxiliary if
-%   appropriate. Otherwise, leave the \meta{4~bytes} \cs{s__tl} behind,
-%   then check that the code point is not overflowing: the leading byte
-%   must be $0$, and the following byte at most $16$.
-%
-%   In the ending code, we check that there remains no byte: there
-%   should be nothing left until the first \cs{s__stop}. Break the map.
-%    \begin{macrocode}
-  \cs_new_protected_nopar:cpn { @@_convert_decode_utf32be: }
-    { \@@_decode_utf_xxxii:Nw 1 \g_@@_result_tl \s__stop }
-  \cs_new_protected_nopar:cpn { @@_convert_decode_utf32le: }
-    { \@@_decode_utf_xxxii:Nw 2 \g_@@_result_tl \s__stop }
-  \cs_new_protected_nopar:cpn { @@_convert_decode_utf32: }
-    {
-      \exp_after:wN \@@_decode_utf_xxxii_bom:NNNN \g_@@_result_tl
-        \s__stop \s__stop \s__stop \s__stop \s__stop
-    }
-  \cs_new_protected:Npn \@@_decode_utf_xxxii_bom:NNNN #1#2#3#4
-    {
-      \str_if_eq_x:nnTF { #1#2#3#4 } { ^^ff ^^fe ^^00 ^^00 }
-        { \@@_decode_utf_xxxii:Nw 2 }
-        {
-          \str_if_eq_x:nnTF { #1#2#3#4 } { ^^00 ^^00 ^^fe ^^ff }
-            { \@@_decode_utf_xxxii:Nw 1 }
-            { \@@_decode_utf_xxxii:Nw 1 #1#2#3#4 }
-        }
-    }
-  \cs_new_protected:Npn \@@_decode_utf_xxxii:Nw #1#2 \s__stop
-    {
-      \flag_clear:n { str_overflow }
-      \flag_clear:n { str_end }
-      \flag_clear:n { str_error }
-      \cs_set:Npn \@@_tmp:w ##1 ##2 { ` ## #1 }
-      \tl_gset:Nx \g_@@_result_tl
-        {
-          \exp_after:wN \@@_decode_utf_xxxii_loop:NNNN
-            #2 \s__stop \s__stop \s__stop \s__stop
-          \__prg_break_point:
-        }
-      \@@_if_flag_error:nnx { str_error } { utf32-decode } { }
-    }
-  \cs_new:Npn \@@_decode_utf_xxxii_loop:NNNN #1#2#3#4
-    {
-      \if_meaning:w \s__stop #4
-        \exp_after:wN \@@_decode_utf_xxxii_end:w
-      \fi:
-      #1#2#3#4 \s__tl
-      \if_int_compare:w \@@_tmp:w #1#4 > \c_zero
-        \flag_raise:n { str_overflow }
-        \flag_raise:n { str_error }
-        \int_use:N \c_@@_replacement_char_int
-      \else:
-        \if_int_compare:w \@@_tmp:w #2#3 > \c_sixteen
-          \flag_raise:n { str_overflow }
-          \flag_raise:n { str_error }
-          \int_use:N \c_@@_replacement_char_int
-        \else:
-          \int_eval:n
-            { \@@_tmp:w #2#3*"10000 + \@@_tmp:w #3#2*"100 + \@@_tmp:w #4#1 }
-        \fi:
-      \fi:
-      \s__tl
-      \@@_decode_utf_xxxii_loop:NNNN
-    }
-  \cs_new:Npn \@@_decode_utf_xxxii_end:w #1 \s__stop
-    {
-      \tl_if_empty:nF {#1}
-        {
-          \flag_raise:n { str_end }
-          \flag_raise:n { str_error }
-          #1 \s__tl
-          \int_use:N \c_@@_replacement_char_int \s__tl
-        }
-      \__prg_break:
-    }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% Restore the original catcodes of bytes $0$, $254$ and $255$.
-%    \begin{macrocode}
-\group_end:
-%</utf32>
-%    \end{macrocode}
-%
-% \subsubsection{\textsc{iso 8859} support}
-%
-% The \textsc{iso-8859-1} encoding exactly matches with the $256$ first
-% Unicode characters. For other 8-bit encodings of the \textsc{iso-8859}
-% family, we keep track only of differences, and of unassigned bytes.
-%    \begin{macrocode}
-%<*iso88591>
-\@@_declare_eight_bit_encoding:nnn { iso88591 }
-  {
-  }
-  {
-  }
-%</iso88591>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88592>
-\@@_declare_eight_bit_encoding:nnn { iso88592 }
-  {
-    { A1 } { 0104 }
-    { A2 } { 02D8 }
-    { A3 } { 0141 }
-    { A5 } { 013D }
-    { A6 } { 015A }
-    { A9 } { 0160 }
-    { AA } { 015E }
-    { AB } { 0164 }
-    { AC } { 0179 }
-    { AE } { 017D }
-    { AF } { 017B }
-    { B1 } { 0105 }
-    { B2 } { 02DB }
-    { B3 } { 0142 }
-    { B5 } { 013E }
-    { B6 } { 015B }
-    { B7 } { 02C7 }
-    { B9 } { 0161 }
-    { BA } { 015F }
-    { BB } { 0165 }
-    { BC } { 017A }
-    { BD } { 02DD }
-    { BE } { 017E }
-    { BF } { 017C }
-    { C0 } { 0154 }
-    { C3 } { 0102 }
-    { C5 } { 0139 }
-    { C6 } { 0106 }
-    { C8 } { 010C }
-    { CA } { 0118 }
-    { CC } { 011A }
-    { CF } { 010E }
-    { D0 } { 0110 }
-    { D1 } { 0143 }
-    { D2 } { 0147 }
-    { D5 } { 0150 }
-    { D8 } { 0158 }
-    { D9 } { 016E }
-    { DB } { 0170 }
-    { DE } { 0162 }
-    { E0 } { 0155 }
-    { E3 } { 0103 }
-    { E5 } { 013A }
-    { E6 } { 0107 }
-    { E8 } { 010D }
-    { EA } { 0119 }
-    { EC } { 011B }
-    { EF } { 010F }
-    { F0 } { 0111 }
-    { F1 } { 0144 }
-    { F2 } { 0148 }
-    { F5 } { 0151 }
-    { F8 } { 0159 }
-    { F9 } { 016F }
-    { FB } { 0171 }
-    { FE } { 0163 }
-    { FF } { 02D9 }
-  }
-  {
-  }
-%</iso88592>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88593>
-\@@_declare_eight_bit_encoding:nnn { iso88593 }
-  {
-    { A1 } { 0126 }
-    { A2 } { 02D8 }
-    { A6 } { 0124 }
-    { A9 } { 0130 }
-    { AA } { 015E }
-    { AB } { 011E }
-    { AC } { 0134 }
-    { AF } { 017B }
-    { B1 } { 0127 }
-    { B6 } { 0125 }
-    { B9 } { 0131 }
-    { BA } { 015F }
-    { BB } { 011F }
-    { BC } { 0135 }
-    { BF } { 017C }
-    { C5 } { 010A }
-    { C6 } { 0108 }
-    { D5 } { 0120 }
-    { D8 } { 011C }
-    { DD } { 016C }
-    { DE } { 015C }
-    { E5 } { 010B }
-    { E6 } { 0109 }
-    { F5 } { 0121 }
-    { F8 } { 011D }
-    { FD } { 016D }
-    { FE } { 015D }
-    { FF } { 02D9 }
-  }
-  {
-    { A5 }
-    { AE }
-    { BE }
-    { C3 }
-    { D0 }
-    { E3 }
-    { F0 }
-  }
-%</iso88593>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88594>
-\@@_declare_eight_bit_encoding:nnn { iso88594 }
-  {
-    { A1 } { 0104 }
-    { A2 } { 0138 }
-    { A3 } { 0156 }
-    { A5 } { 0128 }
-    { A6 } { 013B }
-    { A9 } { 0160 }
-    { AA } { 0112 }
-    { AB } { 0122 }
-    { AC } { 0166 }
-    { AE } { 017D }
-    { B1 } { 0105 }
-    { B2 } { 02DB }
-    { B3 } { 0157 }
-    { B5 } { 0129 }
-    { B6 } { 013C }
-    { B7 } { 02C7 }
-    { B9 } { 0161 }
-    { BA } { 0113 }
-    { BB } { 0123 }
-    { BC } { 0167 }
-    { BD } { 014A }
-    { BE } { 017E }
-    { BF } { 014B }
-    { C0 } { 0100 }
-    { C7 } { 012E }
-    { C8 } { 010C }
-    { CA } { 0118 }
-    { CC } { 0116 }
-    { CF } { 012A }
-    { D0 } { 0110 }
-    { D1 } { 0145 }
-    { D2 } { 014C }
-    { D3 } { 0136 }
-    { D9 } { 0172 }
-    { DD } { 0168 }
-    { DE } { 016A }
-    { E0 } { 0101 }
-    { E7 } { 012F }
-    { E8 } { 010D }
-    { EA } { 0119 }
-    { EC } { 0117 }
-    { EF } { 012B }
-    { F0 } { 0111 }
-    { F1 } { 0146 }
-    { F2 } { 014D }
-    { F3 } { 0137 }
-    { F9 } { 0173 }
-    { FD } { 0169 }
-    { FE } { 016B }
-    { FF } { 02D9 }
-  }
-  {
-  }
-%</iso88594>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88595>
-\@@_declare_eight_bit_encoding:nnn { iso88595 }
-  {
-    { A1 } { 0401 }
-    { A2 } { 0402 }
-    { A3 } { 0403 }
-    { A4 } { 0404 }
-    { A5 } { 0405 }
-    { A6 } { 0406 }
-    { A7 } { 0407 }
-    { A8 } { 0408 }
-    { A9 } { 0409 }
-    { AA } { 040A }
-    { AB } { 040B }
-    { AC } { 040C }
-    { AE } { 040E }
-    { AF } { 040F }
-    { B0 } { 0410 }
-    { B1 } { 0411 }
-    { B2 } { 0412 }
-    { B3 } { 0413 }
-    { B4 } { 0414 }
-    { B5 } { 0415 }
-    { B6 } { 0416 }
-    { B7 } { 0417 }
-    { B8 } { 0418 }
-    { B9 } { 0419 }
-    { BA } { 041A }
-    { BB } { 041B }
-    { BC } { 041C }
-    { BD } { 041D }
-    { BE } { 041E }
-    { BF } { 041F }
-    { C0 } { 0420 }
-    { C1 } { 0421 }
-    { C2 } { 0422 }
-    { C3 } { 0423 }
-    { C4 } { 0424 }
-    { C5 } { 0425 }
-    { C6 } { 0426 }
-    { C7 } { 0427 }
-    { C8 } { 0428 }
-    { C9 } { 0429 }
-    { CA } { 042A }
-    { CB } { 042B }
-    { CC } { 042C }
-    { CD } { 042D }
-    { CE } { 042E }
-    { CF } { 042F }
-    { D0 } { 0430 }
-    { D1 } { 0431 }
-    { D2 } { 0432 }
-    { D3 } { 0433 }
-    { D4 } { 0434 }
-    { D5 } { 0435 }
-    { D6 } { 0436 }
-    { D7 } { 0437 }
-    { D8 } { 0438 }
-    { D9 } { 0439 }
-    { DA } { 043A }
-    { DB } { 043B }
-    { DC } { 043C }
-    { DD } { 043D }
-    { DE } { 043E }
-    { DF } { 043F }
-    { E0 } { 0440 }
-    { E1 } { 0441 }
-    { E2 } { 0442 }
-    { E3 } { 0443 }
-    { E4 } { 0444 }
-    { E5 } { 0445 }
-    { E6 } { 0446 }
-    { E7 } { 0447 }
-    { E8 } { 0448 }
-    { E9 } { 0449 }
-    { EA } { 044A }
-    { EB } { 044B }
-    { EC } { 044C }
-    { ED } { 044D }
-    { EE } { 044E }
-    { EF } { 044F }
-    { F0 } { 2116 }
-    { F1 } { 0451 }
-    { F2 } { 0452 }
-    { F3 } { 0453 }
-    { F4 } { 0454 }
-    { F5 } { 0455 }
-    { F6 } { 0456 }
-    { F7 } { 0457 }
-    { F8 } { 0458 }
-    { F9 } { 0459 }
-    { FA } { 045A }
-    { FB } { 045B }
-    { FC } { 045C }
-    { FD } { 00A7 }
-    { FE } { 045E }
-    { FF } { 045F }
-  }
-  {
-  }
-%</iso88595>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88596>
-\@@_declare_eight_bit_encoding:nnn { iso88596 }
-  {
-    { AC } { 060C }
-    { BB } { 061B }
-    { BF } { 061F }
-    { C1 } { 0621 }
-    { C2 } { 0622 }
-    { C3 } { 0623 }
-    { C4 } { 0624 }
-    { C5 } { 0625 }
-    { C6 } { 0626 }
-    { C7 } { 0627 }
-    { C8 } { 0628 }
-    { C9 } { 0629 }
-    { CA } { 062A }
-    { CB } { 062B }
-    { CC } { 062C }
-    { CD } { 062D }
-    { CE } { 062E }
-    { CF } { 062F }
-    { D0 } { 0630 }
-    { D1 } { 0631 }
-    { D2 } { 0632 }
-    { D3 } { 0633 }
-    { D4 } { 0634 }
-    { D5 } { 0635 }
-    { D6 } { 0636 }
-    { D7 } { 0637 }
-    { D8 } { 0638 }
-    { D9 } { 0639 }
-    { DA } { 063A }
-    { E0 } { 0640 }
-    { E1 } { 0641 }
-    { E2 } { 0642 }
-    { E3 } { 0643 }
-    { E4 } { 0644 }
-    { E5 } { 0645 }
-    { E6 } { 0646 }
-    { E7 } { 0647 }
-    { E8 } { 0648 }
-    { E9 } { 0649 }
-    { EA } { 064A }
-    { EB } { 064B }
-    { EC } { 064C }
-    { ED } { 064D }
-    { EE } { 064E }
-    { EF } { 064F }
-    { F0 } { 0650 }
-    { F1 } { 0651 }
-    { F2 } { 0652 }
-  }
-  {
-    { A1 }
-    { A2 }
-    { A3 }
-    { A5 }
-    { A6 }
-    { A7 }
-    { A8 }
-    { A9 }
-    { AA }
-    { AB }
-    { AE }
-    { AF }
-    { B0 }
-    { B1 }
-    { B2 }
-    { B3 }
-    { B4 }
-    { B5 }
-    { B6 }
-    { B7 }
-    { B8 }
-    { B9 }
-    { BA }
-    { BC }
-    { BD }
-    { BE }
-    { C0 }
-    { DB }
-    { DC }
-    { DD }
-    { DE }
-    { DF }
-  }
-%</iso88596>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88597>
-\@@_declare_eight_bit_encoding:nnn { iso88597 }
-  {
-    { A1 } { 2018 }
-    { A2 } { 2019 }
-    { A4 } { 20AC }
-    { A5 } { 20AF }
-    { AA } { 037A }
-    { AF } { 2015 }
-    { B4 } { 0384 }
-    { B5 } { 0385 }
-    { B6 } { 0386 }
-    { B8 } { 0388 }
-    { B9 } { 0389 }
-    { BA } { 038A }
-    { BC } { 038C }
-    { BE } { 038E }
-    { BF } { 038F }
-    { C0 } { 0390 }
-    { C1 } { 0391 }
-    { C2 } { 0392 }
-    { C3 } { 0393 }
-    { C4 } { 0394 }
-    { C5 } { 0395 }
-    { C6 } { 0396 }
-    { C7 } { 0397 }
-    { C8 } { 0398 }
-    { C9 } { 0399 }
-    { CA } { 039A }
-    { CB } { 039B }
-    { CC } { 039C }
-    { CD } { 039D }
-    { CE } { 039E }
-    { CF } { 039F }
-    { D0 } { 03A0 }
-    { D1 } { 03A1 }
-    { D3 } { 03A3 }
-    { D4 } { 03A4 }
-    { D5 } { 03A5 }
-    { D6 } { 03A6 }
-    { D7 } { 03A7 }
-    { D8 } { 03A8 }
-    { D9 } { 03A9 }
-    { DA } { 03AA }
-    { DB } { 03AB }
-    { DC } { 03AC }
-    { DD } { 03AD }
-    { DE } { 03AE }
-    { DF } { 03AF }
-    { E0 } { 03B0 }
-    { E1 } { 03B1 }
-    { E2 } { 03B2 }
-    { E3 } { 03B3 }
-    { E4 } { 03B4 }
-    { E5 } { 03B5 }
-    { E6 } { 03B6 }
-    { E7 } { 03B7 }
-    { E8 } { 03B8 }
-    { E9 } { 03B9 }
-    { EA } { 03BA }
-    { EB } { 03BB }
-    { EC } { 03BC }
-    { ED } { 03BD }
-    { EE } { 03BE }
-    { EF } { 03BF }
-    { F0 } { 03C0 }
-    { F1 } { 03C1 }
-    { F2 } { 03C2 }
-    { F3 } { 03C3 }
-    { F4 } { 03C4 }
-    { F5 } { 03C5 }
-    { F6 } { 03C6 }
-    { F7 } { 03C7 }
-    { F8 } { 03C8 }
-    { F9 } { 03C9 }
-    { FA } { 03CA }
-    { FB } { 03CB }
-    { FC } { 03CC }
-    { FD } { 03CD }
-    { FE } { 03CE }
-  }
-  {
-    { AE }
-    { D2 }
-  }
-%</iso88597>
-%    \end{macrocode}
-%
 %    \begin{macrocode}
-%<*iso88598>
-\@@_declare_eight_bit_encoding:nnn { iso88598 }
-  {
-    { AA } { 00D7 }
-    { BA } { 00F7 }
-    { DF } { 2017 }
-    { E0 } { 05D0 }
-    { E1 } { 05D1 }
-    { E2 } { 05D2 }
-    { E3 } { 05D3 }
-    { E4 } { 05D4 }
-    { E5 } { 05D5 }
-    { E6 } { 05D6 }
-    { E7 } { 05D7 }
-    { E8 } { 05D8 }
-    { E9 } { 05D9 }
-    { EA } { 05DA }
-    { EB } { 05DB }
-    { EC } { 05DC }
-    { ED } { 05DD }
-    { EE } { 05DE }
-    { EF } { 05DF }
-    { F0 } { 05E0 }
-    { F1 } { 05E1 }
-    { F2 } { 05E2 }
-    { F3 } { 05E3 }
-    { F4 } { 05E4 }
-    { F5 } { 05E5 }
-    { F6 } { 05E6 }
-    { F7 } { 05E7 }
-    { F8 } { 05E8 }
-    { F9 } { 05E9 }
-    { FA } { 05EA }
-    { FD } { 200E }
-    { FE } { 200F }
-  }
-  {
-    { A1 }
-    { BF }
-    { C0 }
-    { C1 }
-    { C2 }
-    { C3 }
-    { C4 }
-    { C5 }
-    { C6 }
-    { C7 }
-    { C8 }
-    { C9 }
-    { CA }
-    { CB }
-    { CC }
-    { CD }
-    { CE }
-    { CF }
-    { D0 }
-    { D1 }
-    { D2 }
-    { D3 }
-    { D4 }
-    { D5 }
-    { D6 }
-    { D7 }
-    { D8 }
-    { D9 }
-    { DA }
-    { DB }
-    { DC }
-    { DD }
-    { DE }
-    { FB }
-    { FC }
-  }
-%</iso88598>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso88599>
-\@@_declare_eight_bit_encoding:nnn { iso88599 }
-  {
-    { D0 } { 011E }
-    { DD } { 0130 }
-    { DE } { 015E }
-    { F0 } { 011F }
-    { FD } { 0131 }
-    { FE } { 015F }
-  }
-  {
-  }
-%</iso88599>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso885910>
-\@@_declare_eight_bit_encoding:nnn { iso885910 }
-  {
-    { A1 } { 0104 }
-    { A2 } { 0112 }
-    { A3 } { 0122 }
-    { A4 } { 012A }
-    { A5 } { 0128 }
-    { A6 } { 0136 }
-    { A8 } { 013B }
-    { A9 } { 0110 }
-    { AA } { 0160 }
-    { AB } { 0166 }
-    { AC } { 017D }
-    { AE } { 016A }
-    { AF } { 014A }
-    { B1 } { 0105 }
-    { B2 } { 0113 }
-    { B3 } { 0123 }
-    { B4 } { 012B }
-    { B5 } { 0129 }
-    { B6 } { 0137 }
-    { B8 } { 013C }
-    { B9 } { 0111 }
-    { BA } { 0161 }
-    { BB } { 0167 }
-    { BC } { 017E }
-    { BD } { 2015 }
-    { BE } { 016B }
-    { BF } { 014B }
-    { C0 } { 0100 }
-    { C7 } { 012E }
-    { C8 } { 010C }
-    { CA } { 0118 }
-    { CC } { 0116 }
-    { D1 } { 0145 }
-    { D2 } { 014C }
-    { D7 } { 0168 }
-    { D9 } { 0172 }
-    { E0 } { 0101 }
-    { E7 } { 012F }
-    { E8 } { 010D }
-    { EA } { 0119 }
-    { EC } { 0117 }
-    { F1 } { 0146 }
-    { F2 } { 014D }
-    { F7 } { 0169 }
-    { F9 } { 0173 }
-    { FF } { 0138 }
-  }
-  {
-  }
-%</iso885910>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso885911>
-\@@_declare_eight_bit_encoding:nnn { iso885911 }
-  {
-    { A1 } { 0E01 }
-    { A2 } { 0E02 }
-    { A3 } { 0E03 }
-    { A4 } { 0E04 }
-    { A5 } { 0E05 }
-    { A6 } { 0E06 }
-    { A7 } { 0E07 }
-    { A8 } { 0E08 }
-    { A9 } { 0E09 }
-    { AA } { 0E0A }
-    { AB } { 0E0B }
-    { AC } { 0E0C }
-    { AD } { 0E0D }
-    { AE } { 0E0E }
-    { AF } { 0E0F }
-    { B0 } { 0E10 }
-    { B1 } { 0E11 }
-    { B2 } { 0E12 }
-    { B3 } { 0E13 }
-    { B4 } { 0E14 }
-    { B5 } { 0E15 }
-    { B6 } { 0E16 }
-    { B7 } { 0E17 }
-    { B8 } { 0E18 }
-    { B9 } { 0E19 }
-    { BA } { 0E1A }
-    { BB } { 0E1B }
-    { BC } { 0E1C }
-    { BD } { 0E1D }
-    { BE } { 0E1E }
-    { BF } { 0E1F }
-    { C0 } { 0E20 }
-    { C1 } { 0E21 }
-    { C2 } { 0E22 }
-    { C3 } { 0E23 }
-    { C4 } { 0E24 }
-    { C5 } { 0E25 }
-    { C6 } { 0E26 }
-    { C7 } { 0E27 }
-    { C8 } { 0E28 }
-    { C9 } { 0E29 }
-    { CA } { 0E2A }
-    { CB } { 0E2B }
-    { CC } { 0E2C }
-    { CD } { 0E2D }
-    { CE } { 0E2E }
-    { CF } { 0E2F }
-    { D0 } { 0E30 }
-    { D1 } { 0E31 }
-    { D2 } { 0E32 }
-    { D3 } { 0E33 }
-    { D4 } { 0E34 }
-    { D5 } { 0E35 }
-    { D6 } { 0E36 }
-    { D7 } { 0E37 }
-    { D8 } { 0E38 }
-    { D9 } { 0E39 }
-    { DA } { 0E3A }
-    { DF } { 0E3F }
-    { E0 } { 0E40 }
-    { E1 } { 0E41 }
-    { E2 } { 0E42 }
-    { E3 } { 0E43 }
-    { E4 } { 0E44 }
-    { E5 } { 0E45 }
-    { E6 } { 0E46 }
-    { E7 } { 0E47 }
-    { E8 } { 0E48 }
-    { E9 } { 0E49 }
-    { EA } { 0E4A }
-    { EB } { 0E4B }
-    { EC } { 0E4C }
-    { ED } { 0E4D }
-    { EE } { 0E4E }
-    { EF } { 0E4F }
-    { F0 } { 0E50 }
-    { F1 } { 0E51 }
-    { F2 } { 0E52 }
-    { F3 } { 0E53 }
-    { F4 } { 0E54 }
-    { F5 } { 0E55 }
-    { F6 } { 0E56 }
-    { F7 } { 0E57 }
-    { F8 } { 0E58 }
-    { F9 } { 0E59 }
-    { FA } { 0E5A }
-    { FB } { 0E5B }
-  }
-  {
-    { DB }
-    { DC }
-    { DD }
-    { DE }
-  }
-%</iso885911>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso885913>
-\@@_declare_eight_bit_encoding:nnn { iso885913 }
-  {
-    { A1 } { 201D }
-    { A5 } { 201E }
-    { A8 } { 00D8 }
-    { AA } { 0156 }
-    { AF } { 00C6 }
-    { B4 } { 201C }
-    { B8 } { 00F8 }
-    { BA } { 0157 }
-    { BF } { 00E6 }
-    { C0 } { 0104 }
-    { C1 } { 012E }
-    { C2 } { 0100 }
-    { C3 } { 0106 }
-    { C6 } { 0118 }
-    { C7 } { 0112 }
-    { C8 } { 010C }
-    { CA } { 0179 }
-    { CB } { 0116 }
-    { CC } { 0122 }
-    { CD } { 0136 }
-    { CE } { 012A }
-    { CF } { 013B }
-    { D0 } { 0160 }
-    { D1 } { 0143 }
-    { D2 } { 0145 }
-    { D4 } { 014C }
-    { D8 } { 0172 }
-    { D9 } { 0141 }
-    { DA } { 015A }
-    { DB } { 016A }
-    { DD } { 017B }
-    { DE } { 017D }
-    { E0 } { 0105 }
-    { E1 } { 012F }
-    { E2 } { 0101 }
-    { E3 } { 0107 }
-    { E6 } { 0119 }
-    { E7 } { 0113 }
-    { E8 } { 010D }
-    { EA } { 017A }
-    { EB } { 0117 }
-    { EC } { 0123 }
-    { ED } { 0137 }
-    { EE } { 012B }
-    { EF } { 013C }
-    { F0 } { 0161 }
-    { F1 } { 0144 }
-    { F2 } { 0146 }
-    { F4 } { 014D }
-    { F8 } { 0173 }
-    { F9 } { 0142 }
-    { FA } { 015B }
-    { FB } { 016B }
-    { FD } { 017C }
-    { FE } { 017E }
-    { FF } { 2019 }
-  }
-  {
-  }
-%</iso885913>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso885914>
-\@@_declare_eight_bit_encoding:nnn { iso885914 }
-  {
-    { A1 } { 1E02 }
-    { A2 } { 1E03 }
-    { A4 } { 010A }
-    { A5 } { 010B }
-    { A6 } { 1E0A }
-    { A8 } { 1E80 }
-    { AA } { 1E82 }
-    { AB } { 1E0B }
-    { AC } { 1EF2 }
-    { AF } { 0178 }
-    { B0 } { 1E1E }
-    { B1 } { 1E1F }
-    { B2 } { 0120 }
-    { B3 } { 0121 }
-    { B4 } { 1E40 }
-    { B5 } { 1E41 }
-    { B7 } { 1E56 }
-    { B8 } { 1E81 }
-    { B9 } { 1E57 }
-    { BA } { 1E83 }
-    { BB } { 1E60 }
-    { BC } { 1EF3 }
-    { BD } { 1E84 }
-    { BE } { 1E85 }
-    { BF } { 1E61 }
-    { D0 } { 0174 }
-    { D7 } { 1E6A }
-    { DE } { 0176 }
-    { F0 } { 0175 }
-    { F7 } { 1E6B }
-    { FE } { 0177 }
-  }
-  {
-  }
-%</iso885914>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso885915>
-\@@_declare_eight_bit_encoding:nnn { iso885915 }
-  {
-    { A4 } { 20AC }
-    { A6 } { 0160 }
-    { A8 } { 0161 }
-    { B4 } { 017D }
-    { B8 } { 017E }
-    { BC } { 0152 }
-    { BD } { 0153 }
-    { BE } { 0178 }
-  }
-  {
-  }
-%</iso885915>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*iso885916>
-\@@_declare_eight_bit_encoding:nnn { iso885916 }
-  {
-    { A1 } { 0104 }
-    { A2 } { 0105 }
-    { A3 } { 0141 }
-    { A4 } { 20AC }
-    { A5 } { 201E }
-    { A6 } { 0160 }
-    { A8 } { 0161 }
-    { AA } { 0218 }
-    { AC } { 0179 }
-    { AE } { 017A }
-    { AF } { 017B }
-    { B2 } { 010C }
-    { B3 } { 0142 }
-    { B4 } { 017D }
-    { B5 } { 201D }
-    { B8 } { 017E }
-    { B9 } { 010D }
-    { BA } { 0219 }
-    { BC } { 0152 }
-    { BD } { 0153 }
-    { BE } { 0178 }
-    { BF } { 017C }
-    { C3 } { 0102 }
-    { C5 } { 0106 }
-    { D0 } { 0110 }
-    { D1 } { 0143 }
-    { D5 } { 0150 }
-    { D7 } { 015A }
-    { D8 } { 0170 }
-    { DD } { 0118 }
-    { DE } { 021A }
-    { E3 } { 0103 }
-    { E5 } { 0107 }
-    { F0 } { 0111 }
-    { F1 } { 0144 }
-    { F5 } { 0151 }
-    { F7 } { 015B }
-    { F8 } { 0171 }
-    { FD } { 0119 }
-    { FE } { 021B }
-  }
-  {
-  }
-%</iso885916>
+%</initex|package>
 %    \end{macrocode}
 %
 % \end{implementation}
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.ins b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.ins
index 4605b50c851..8f6983abde3 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.ins
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3str.ins
@@ -1,6 +1,6 @@
 \iffalse meta-comment
 
-File l3str.ins Copyright (C) 2011 The LaTeX3 Project
+File l3str.ins Copyright (C) 2011, 2013 The LaTeX3 Project
 
 It may be distributed and/or modified under the conditions of the
 LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -38,6 +38,7 @@ Do not distribute a modified version of this file.
 \generate{\file{l3flag.sty}   {\from{l3flag.dtx}   {package}}}
 \generate{\file{l3str.sty}    {\from{l3str.dtx}    {package}}}
 \generate{\file{l3regex.sty}  {\from{l3regex.dtx}  {package}}}
+\generate{\file{l3str-convert.sty}  {\from{l3str-convert.dtx}  {package}}}
 \generate{\file{l3str-format.sty}   {\from{l3str-format.dtx}   {package}}}
 \generate{\file{l3tl-analysis.sty}  {\from{l3tl-analysis.dtx}  {package}}}
 \generate{\file{l3tl-build.sty}     {\from{l3tl-build.dtx}     {package}}}
@@ -45,36 +46,36 @@ Do not distribute a modified version of this file.
 
 % Escapings.
 \generate{%
-  \file{l3str-esc-hex.def}           {\from{l3str.dtx}{hex}}%
-  \file{l3str-esc-name.def}          {\from{l3str.dtx}{name}}%
-  \file{l3str-esc-string.def}        {\from{l3str.dtx}{string}}%
-  \file{l3str-esc-url.def}           {\from{l3str.dtx}{url}}%
+  \file{l3str-esc-hex.def}           {\from{l3str-convert.dtx}{hex}}%
+  \file{l3str-esc-name.def}          {\from{l3str-convert.dtx}{name}}%
+  \file{l3str-esc-string.def}        {\from{l3str-convert.dtx}{string}}%
+  \file{l3str-esc-url.def}           {\from{l3str-convert.dtx}{url}}%
 }
 
 % UTF encodings.
 \generate{%
-  \file{l3str-enc-utf8.def}   {\from{l3str.dtx}{utf8}}%
-  \file{l3str-enc-utf16.def}  {\from{l3str.dtx}{utf16}}%
-  \file{l3str-enc-utf32.def}  {\from{l3str.dtx}{utf32}}%
+  \file{l3str-enc-utf8.def}   {\from{l3str-convert.dtx}{utf8}}%
+  \file{l3str-enc-utf16.def}  {\from{l3str-convert.dtx}{utf16}}%
+  \file{l3str-enc-utf32.def}  {\from{l3str-convert.dtx}{utf32}}%
 }
 
 % ISO-8859 encodings.
 \generate{%
-  \file{l3str-enc-iso88591.def}  {\from{l3str.dtx}{iso88591}}%
-  \file{l3str-enc-iso88592.def}  {\from{l3str.dtx}{iso88592}}%
-  \file{l3str-enc-iso88593.def}  {\from{l3str.dtx}{iso88593}}%
-  \file{l3str-enc-iso88594.def}  {\from{l3str.dtx}{iso88594}}%
-  \file{l3str-enc-iso88595.def}  {\from{l3str.dtx}{iso88595}}%
-  \file{l3str-enc-iso88596.def}  {\from{l3str.dtx}{iso88596}}%
-  \file{l3str-enc-iso88597.def}  {\from{l3str.dtx}{iso88597}}%
-  \file{l3str-enc-iso88598.def}  {\from{l3str.dtx}{iso88598}}%
-  \file{l3str-enc-iso88599.def}  {\from{l3str.dtx}{iso88599}}%
-  \file{l3str-enc-iso885910.def} {\from{l3str.dtx}{iso885910}}%
-  \file{l3str-enc-iso885911.def} {\from{l3str.dtx}{iso885911}}%
-  \file{l3str-enc-iso885913.def} {\from{l3str.dtx}{iso885913}}%
-  \file{l3str-enc-iso885914.def} {\from{l3str.dtx}{iso885914}}%
-  \file{l3str-enc-iso885915.def} {\from{l3str.dtx}{iso885915}}%
-  \file{l3str-enc-iso885916.def} {\from{l3str.dtx}{iso885916}}%
+  \file{l3str-enc-iso88591.def}  {\from{l3str-convert.dtx}{iso88591}}%
+  \file{l3str-enc-iso88592.def}  {\from{l3str-convert.dtx}{iso88592}}%
+  \file{l3str-enc-iso88593.def}  {\from{l3str-convert.dtx}{iso88593}}%
+  \file{l3str-enc-iso88594.def}  {\from{l3str-convert.dtx}{iso88594}}%
+  \file{l3str-enc-iso88595.def}  {\from{l3str-convert.dtx}{iso88595}}%
+  \file{l3str-enc-iso88596.def}  {\from{l3str-convert.dtx}{iso88596}}%
+  \file{l3str-enc-iso88597.def}  {\from{l3str-convert.dtx}{iso88597}}%
+  \file{l3str-enc-iso88598.def}  {\from{l3str-convert.dtx}{iso88598}}%
+  \file{l3str-enc-iso88599.def}  {\from{l3str-convert.dtx}{iso88599}}%
+  \file{l3str-enc-iso885910.def} {\from{l3str-convert.dtx}{iso885910}}%
+  \file{l3str-enc-iso885911.def} {\from{l3str-convert.dtx}{iso885911}}%
+  \file{l3str-enc-iso885913.def} {\from{l3str-convert.dtx}{iso885913}}%
+  \file{l3str-enc-iso885914.def} {\from{l3str-convert.dtx}{iso885914}}%
+  \file{l3str-enc-iso885915.def} {\from{l3str-convert.dtx}{iso885915}}%
+  \file{l3str-enc-iso885916.def} {\from{l3str-convert.dtx}{iso885916}}%
 }
 
 \endbatchfile
diff --git a/Master/texmf-dist/source/latex/l3experimental/l3str/l3tl-analysis.dtx b/Master/texmf-dist/source/latex/l3experimental/l3str/l3tl-analysis.dtx
index 4ceef260a99..b9e5bbd087e 100644
--- a/Master/texmf-dist/source/latex/l3experimental/l3str/l3tl-analysis.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/l3str/l3tl-analysis.dtx
@@ -126,7 +126,7 @@
 % information about individual tokens (category code, character code),
 % as well as reconstruct the token list quickly. This internal format is
 % used in \pkg{l3regex} where we need to support arbitrary tokens, and
-% it is used in conversion functions in \pkg{l3str}, where we wish to
+% it is used in conversion functions in \pkg{l3str-convert}, where we wish to
 % support clusters of characters instead of single tokens.
 %
 % We thus need a way to encode any \meta{token} (even begin-group and
@@ -143,12 +143,12 @@
 % The \meta{tokens} \texttt{o}- \emph{and} \texttt{x}-expand to the
 % original token in the token list or to the cluster of tokens
 % corresponding to one Unicode character in the given encoding (for
-% \pkg{l3str}). The \meta{catcode} is given as a single hexadecimal
+% \pkg{l3str-convert}). The \meta{catcode} is given as a single hexadecimal
 % digit, $0$ for control sequences. The \meta{char code} is given as a
 % decimal number, $-1$ for control sequences.
 %
 % Using delimited arguments lets us build the \meta{tokens}
-% progressively when doing an encoding conversion in \pkg{l3str}. On the
+% progressively when doing an encoding conversion in \pkg{l3str-convert}. On the
 % other hand, the delimiter \cs{s__tl} may not appear unbraced in
 % \meta{tokens}. This is not a problem because we are careful to wrap
 % control sequences in braces (as an argument to \cs{exp_not:n}) when
@@ -423,7 +423,7 @@
   \cs_new_protected:Npn \@@_disable_loop:N #1
     {
       \tex_lccode:D \c_zero `#1 ~
-      \tl_to_lowercase:n { \tex_let:D ^^@ } \c_undefined:D
+      \tl_to_lowercase:n { \tex_let:D ^^@ } \tex_undefined:D
       \@@_disable_loop:N
     }
 \group_end:
@@ -807,7 +807,7 @@
     {
       \cs_new:Npn \@@_b_char:Nww #1
         {
-          \if_meaning:w #1 \c_undefined:D            ? \else:
+          \if_meaning:w #1 \tex_undefined:D          ? \else:
           \if_catcode:w #1 \c_catcode_other_token    C \else:
           \if_catcode:w #1 \c_catcode_letter_token   B \else:
           \if_catcode:w #1 \c_math_toggle_token      3 \else:
@@ -1073,7 +1073,7 @@
       { \str_count:n { #1 ~ ( #4 #2 #3 ) } }
       > { \l_iow_line_count_int - \c_three }
       {
-        \str_substr:nnn { #1 ~ ( #4 #2 #3 ) } \c_one
+        \str_range:nnn { #1 ~ ( #4 #2 #3 ) } \c_one
           {
             \l_iow_line_count_int - \c_three
             - \str_count:N \c_@@_show_etc_str
diff --git a/Master/texmf-dist/source/latex/l3experimental/xgalley/l3galley.dtx b/Master/texmf-dist/source/latex/l3experimental/xgalley/l3galley.dtx
index e2407f043a7..60ebd14993f 100644
--- a/Master/texmf-dist/source/latex/l3experimental/xgalley/l3galley.dtx
+++ b/Master/texmf-dist/source/latex/l3experimental/xgalley/l3galley.dtx
@@ -37,7 +37,7 @@
 %
 %<*driver|package>
 \RequirePackage{xparse}
-\GetIdInfo$Id: l3galley.dtx 4388 2012-12-20 22:15:35Z joseph $
+\GetIdInfo$Id: l3galley.dtx 4402 2013-01-08 08:59:44Z bruno $
   {L3 Experimental galley code}
 %</driver|package>
 %<*driver>
@@ -279,7 +279,7 @@
 %   \end{syntax}
 %   Adds a cutout section to the active paragraph shape, leaving
 %   \meta{unaltered lines} unchanged and then applying the \meta{indents}
-%   (a comma list). The cutout will be places on the left or right as indicated
+%   (a comma list). The cutout will be placed on the left or right as indicated
 %   by the function name, and will apply to exactly the number of lines
 %   specified (the total of the \meta{unaltered lines} and the number of
 %   entries in the \meta{indents} list). Several cutouts may be applied
diff --git a/Master/texmf-dist/source/latex/l3kernel/expl3.dtx b/Master/texmf-dist/source/latex/l3kernel/expl3.dtx
index 8ea41c4eb2d..b7a91c8d848 100644
--- a/Master/texmf-dist/source/latex/l3kernel/expl3.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/expl3.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: expl3.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: expl3.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -49,8 +49,8 @@
 %<*driver|package>
 \def\ExplFileName{expl3}
 \def\ExplFileDescription{L3 Experimental code bundle wrapper}
-\def\ExplFileDate{2012/12/21}
-\def\ExplFileVersion{4390}
+\def\ExplFileDate{2013/03/12}
+\def\ExplFileVersion{4467}
 %</driver|package>
 %<*driver>
 \documentclass[full]{l3doc}
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3.ins b/Master/texmf-dist/source/latex/l3kernel/l3.ins
new file mode 100644
index 00000000000..b869a70fee5
--- /dev/null
+++ b/Master/texmf-dist/source/latex/l3kernel/l3.ins
@@ -0,0 +1,93 @@
+\iffalse meta-comment
+
+File l3.ins Copyright (C) 2011,2012 The LaTeX3 Project
+
+It may be distributed and/or modified under the conditions of the
+LaTeX Project Public License (LPPL), either version 1.3c of this
+license or (at your option) any later version.  The latest version
+of this license is in the file
+
+   http://www.latex-project.org/lppl.txt
+
+This file is part of the "l3kernel bundle" (The Work in LPPL)
+and all files in that bundle must be distributed together.
+
+The released version of this bundle is available from CTAN.
+
+\fi
+
+\let\jobname\relax
+\input l3docstrip.dtx
+\askforoverwritefalse
+
+\preamble
+
+EXPERIMENTAL CODE
+
+Do not distribute this file without also distributing the
+source files specified above.
+
+Do not distribute a modified version of this file.
+
+\endpreamble
+% stop docstrip adding \endinput
+\postamble
+\endpostamble
+
+\keepsilent
+
+% ===== PACKAGE ONLY ======
+\generate{\file{expl3.sty}       {\from{expl3.dtx}      {package}}}
+% ========================
+\generate{\file{l3bootstrap.sty} {\from{l3bootstrap.dtx}{package}}}
+\generate{\file{l3names.sty}     {\from{l3names.dtx}    {package}}}
+\generate{\file{l3basics.sty}    {\from{l3basics.dtx}   {package}}}
+\generate{\file{l3expan.sty}     {\from{l3expan.dtx}    {package}}}
+\generate{\file{l3tl.sty}        {\from{l3tl.dtx}       {package}}}
+\generate{\file{l3seq.sty}       {\from{l3seq.dtx}      {package}}}
+\generate{\file{l3int.sty}       {\from{l3int.dtx}      {package}}}
+\generate{\file{l3quark.sty}     {\from{l3quark.dtx}    {package}}}
+\generate{\file{l3prg.sty}       {\from{l3prg.dtx}      {package}}}
+\generate{\file{l3clist.sty}     {\from{l3clist.dtx}    {package}}}
+\generate{\file{l3token.sty}     {\from{l3token.dtx}    {package}}}
+\generate{\file{l3prop.sty}      {\from{l3prop.dtx}     {package}}}
+\generate{\file{l3msg.sty}       {\from{l3msg.dtx}      {package}}}
+\generate{\file{l3file.sty}      {\from{l3file.dtx}     {package}}}
+\generate{\file{l3skip.sty}      {\from{l3skip.dtx}     {package}}}
+\generate{\file{l3keys.sty}      {\from{l3keys.dtx}     {package}}}
+\generate
+  {%
+    \file{l3fp.sty}
+      {%
+        \from{l3fp.dtx}         {package}
+        \from{l3fp-aux.dtx}     {package}
+        \from{l3fp-traps.dtx}   {package}
+        \from{l3fp-round.dtx}   {package}
+        \from{l3fp-parse.dtx}   {package}
+        \from{l3fp-logic.dtx}   {package}
+        \from{l3fp-basics.dtx}  {package}
+        \from{l3fp-extended.dtx}{package}
+        \from{l3fp-expo.dtx}    {package}
+        \from{l3fp-trig.dtx}    {package}
+        \from{l3fp-convert.dtx} {package}
+        \from{l3fp-assign.dtx}  {package}
+        \from{l3fp-old.dtx}     {package}
+      }%
+  }
+\generate{\file{l3box.sty}       {\from{l3box.dtx}       {package}}}
+\generate{\file{l3coffins.sty}   {\from{l3coffins.dtx}   {package}}}
+\generate{\file{l3color.sty}     {\from{l3color.dtx}     {package}}}
+\generate{\file{l3luatex.sty}    {\from{l3luatex.dtx}    {package}}}
+\generate{\file{l3candidates.sty}{\from{l3candidates.dtx}{package}}}
+
+\generate{\file{l3doc.cls}       {\from{l3doc.dtx}       {class}}}
+\generate{\file{l3doc.ist}       {\from{l3doc.dtx}       {docist}}}
+
+\generate{\file{l3dvipdfmx.def}  {\from{l3drivers.dtx}   {package,dvipdfmx} }}
+\generate{\file{l3dvips.def}     {\from{l3drivers.dtx}   {package,dvips}    }}
+\generate{\file{l3pdfmode.def}   {\from{l3drivers.dtx}   {package,pdfmode}  }}
+\generate{\file{l3xdvipdfmx.def} {\from{l3drivers.dtx}   {package,xdvipdfmx}}}
+
+\generate{\file{l3docstrip.tex}  {\from{l3docstrip.dtx}  {program}}}
+
+\endbatchfile
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3basics.dtx b/Master/texmf-dist/source/latex/l3kernel/l3basics.dtx
index 733beefe452..98fe66d8b35 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3basics.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3basics.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3basics.dtx Copyright (C) 1990-2012 The LaTeX3 project
+%% File: l3basics.dtx Copyright (C) 1990-2013 The LaTeX3 project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3basics.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3basics.dtx 4428 2013-01-10 13:23:29Z bruno $
   {L3 Basic definitions}
 %</driver|package>
 %<*driver>
@@ -183,8 +183,28 @@
 %      \cs{par} tokens but the function will not expand within an
 %      \texttt{x}-type expansion.
 % \end{description}
+% 
+% Finally, the functions in
+% Subsections~\ref{sec:defining-new-function-1}~and
+% \ref{sec:defining-new-function-2} are primarily meant to define
+% \emph{base functions} only. Base functions can only have the following
+% argument specifiers:
+% \begin{description}
+%   \item[|N| and |n|] No manipulation.
+%   \item[|T| and |F|] Functionally equivalent to |n| (you are actually
+%     encouraged to use the family of |\prg_new_conditional:| functions
+%     described in Section~\ref{sec:new-conditional-functions}).
+%   \item[|p| and |w|] These are special cases.
+% \end{description}
+% 
+% The |\cs_new:| functions below (and friends) do not stop you from using
+% other argument specifiers in your function names, but they do not handle
+% expansion for you. You should define the base function and then use
+% \cs{cs_generate_variant:Nn} to generate custom variants as described in
+% Section~\ref{sec:defining-variants}.
 %
 % \subsection{Defining new functions using parameter text}
+% \label{sec:defining-new-function-1}
 %
 % \begin{function}{\cs_new:Npn, \cs_new:cpn, \cs_new:Npx, \cs_new:cpx}
 %   \begin{syntax}
@@ -373,6 +393,7 @@
 % \end{function}
 %
 % \subsection{Defining new functions using the signature}
+% \label{sec:defining-new-function-2}
 %
 % \begin{function}
 %   {
@@ -777,7 +798,7 @@
 %
 % \begin{function}[EXP]{\cs_to_str:N}
 %   \begin{syntax}
-%     \cs{cs_to_str:N} \Arg{control sequence}
+%     \cs{cs_to_str:N} \meta{control sequence}
 %   \end{syntax}
 %   Converts the given \meta{control sequence} into a series of
 %   characters with category code $12$ (other), except spaces,
@@ -1131,7 +1152,7 @@
 %     ~~|}| \\
 %     ~~\Arg{else code}
 %   \end{syntax}
-%   This function comapres the full expansion of the \meta{test string}
+%   This function compares the full expansion of the \meta{test string}
 %   in turn with the full expansion of the \meta{string cases}. If the two
 %   full expansions are equal (as described for \cs{str_if_eq:nnTF} then the
 %   associated \meta{code} is left in the input stream. If none of the tests
@@ -1145,7 +1166,7 @@
 %
 % \begin{function}[updated = 2011-09-06,EXP,pTF]{\luatex_if_engine:}
 %   \begin{syntax}
-%     \cs{luatex_if_luatex:TF} \Arg{true code} \Arg{false code}
+%     \cs{luatex_if_engine:TF} \Arg{true code} \Arg{false code}
 %   \end{syntax}
 %   Detects is the document is being compiled using \LuaTeX{}.
 % \end{function}
@@ -2608,7 +2629,7 @@
 %   \TeX{} conditionals in case |#1| is unbalanced in this matter.
 %    \begin{macrocode}
 \cs_new_protected:Npn \cs_undefine:N #1
-  { \cs_gset_eq:NN #1 \c_undefined:D }
+  { \cs_gset_eq:NN #1 \tex_undefined:D }
 \cs_new_protected:Npn \cs_undefine:c #1
   {
     \if_cs_exist:w #1 \cs_end:
@@ -2616,7 +2637,7 @@
     \else:
       \exp_after:wN \use_none:n
     \fi:
-    { \cs_gset_eq:cN {#1} \c_undefined:D }
+    { \cs_gset_eq:cN {#1} \tex_undefined:D }
   }
 %    \end{macrocode}
 % \end{macro}
@@ -3226,16 +3247,20 @@
 % \begin{macro}[pTF, EXP]{\str_if_eq:xx}
 %   Not really true \texttt{x}-type expansion
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \str_if_eq_p:xx \str_if_eq_x_p:nn
 \cs_new_eq:NN \str_if_eq:xxT  \str_if_eq_x:nnT
 \cs_new_eq:NN \str_if_eq:xxF  \str_if_eq_x:nnF
 \cs_new_eq:NN \str_if_eq:xxTF \str_if_eq_x:nnTF
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % 
 % \begin{macro}{\chk_if_free_cs:N}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \chk_if_free_cs:N \__chk_if_free_cs:N
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3bootstrap.dtx b/Master/texmf-dist/source/latex/l3kernel/l3bootstrap.dtx
index fc1ae68b7c2..9ce55b15be3 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3bootstrap.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3bootstrap.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3bootstrap.dtx Copyright (C) 2011-2012 The LaTeX3 project
+%% File: l3bootstrap.dtx Copyright (C) 2011-2013 The LaTeX3 project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -119,7 +119,7 @@
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-\GetIdInfo$Id: l3bootstrap.dtx 3991 2012-07-16 19:00:35Z joseph $
+\GetIdInfo$Id: l3bootstrap.dtx 4420 2013-01-08 20:00:04Z joseph $
   {L3 Bootstrap code}
 %</driver|package>
 %<*driver>
@@ -672,6 +672,7 @@
 %   package or format itself. Using an \tn{edef} here makes the
 %   definitions that bit clearer later.
 %    \begin{macrocode}
+%<*deprecated>
 \protected\edef\ExplSyntaxNamesOn
   {%
     \expandafter\noexpand
@@ -686,6 +687,7 @@
     \expandafter\noexpand
       \csname\detokenize{char_set_catcode_math_subscript:n}\endcsname{95}%
   }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3box.dtx b/Master/texmf-dist/source/latex/l3kernel/l3box.dtx
index c6ccdfb12a9..b6e89bde0be 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3box.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3box.dtx
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3box.dtx 4347 2012-12-08 09:11:29Z joseph $
+\GetIdInfo$Id: l3box.dtx 4411 2013-01-08 12:21:52Z bruno $
   {L3 Experimental boxes}
 %</driver|package>
 %<*driver>
@@ -760,14 +760,8 @@
 % \begin{macro}[pTF]{\box_if_exist:N, \box_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \box_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \box_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \box_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \box_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \box_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \box_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \box_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \box_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \box_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \box_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3candidates.dtx b/Master/texmf-dist/source/latex/l3kernel/l3candidates.dtx
index 4aa22e27714..88a4d9898b5 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3candidates.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3candidates.dtx
@@ -36,7 +36,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3candidates.dtx 4383 2012-12-20 15:10:48Z bruno $
+\GetIdInfo$Id: l3candidates.dtx 4466 2013-03-09 14:58:43Z joseph $
   {L3 Experimental additions to l3kernel}
 %</driver|package>
 %<*driver>
@@ -406,7 +406,7 @@
 %     \cs{ior_str_map_inline:Nn} \Arg{stream} \Arg{inline function}
 %   \end{syntax}
 %   Applies the \meta{inline function} to every \meta{line}
-%   in the \meta{sream}. The material is read from the \meta{stream}
+%   in the \meta{stream}. The material is read from the \meta{stream}
 %   as a series of tokens with category code $12$ (other), with the
 %   exception of space characters which are given category code $10$
 %   (space). The \meta{inline function} should consist of code which
@@ -2243,12 +2243,14 @@
 \cs_new:Npn \prop_map_tokens:Nn #1#2
   {
     \exp_last_unbraced:Nno \@@_map_tokens:nwn {#2} #1
-    \q_recursion_tail \q__prop { }
+    \s_@@ \q_recursion_tail \s_@@ { }
     \__prg_break_point:Nn \prop_map_break: { }
   }
-\cs_new:Npn \@@_map_tokens:nwn #1 \q__prop #2 \q__prop #3
+\cs_new:Npn \@@_map_tokens:nwn #1 \s_@@ #2 \s_@@ #3
   {
-    \__quark_if_recursion_tail_break:NN #2 \prop_map_break:
+    \if_meaning:w \q_recursion_tail #2
+      \exp_after:wN \prop_map_break:
+    \fi:
     \use:n {#1} {#2} {#3}
     \@@_map_tokens:nwn {#1}
   }
@@ -2271,10 +2273,10 @@
   {
     \exp_last_unbraced:Noo \@@_get_Nn:nwn
       { \tl_to_str:n {#2} } #1
-      \tl_to_str:n {#2} \q__prop { }
+      \tl_to_str:n {#2} \q_@@ { }
     \__prg_break_point:
   }
-\cs_new:Npn \@@_get_Nn:nwn #1 \q__prop #2 \q__prop #3
+\cs_new:Npn \@@_get_Nn:nwn #1 \q_@@ #2 \q_@@ #3
   {
     \str_if_eq_x:nnTF {#1} {#2}
       { \__prg_break:n { \exp_not:n {#3} } }
@@ -2886,11 +2888,11 @@
             \exp_after:wN \@@_false:w
           \fi:
         }
-      \cs_new_protected_nopar:Npn \@@_N_type:w #1 OUTER #2 \q_mark #3
+      \cs_new_protected:Npn \@@_N_type:w #1 OUTER #2 \q_mark #3
         { #3 {#1} {#2} }
     }
 \group_end:
-\cs_new_protected_nopar:Npn \@@_N_type_aux:nnw #1 #2 #3 \fi:
+\cs_new_protected:Npn \@@_N_type_aux:nnw #1 #2 #3 \fi:
   {
     \fi:
     \tl_if_in:noTF {#1} { \tl_to_str:n {ma} }
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3clist.dtx b/Master/texmf-dist/source/latex/l3kernel/l3clist.dtx
index 68c36d63a4a..333bbb9402a 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3clist.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3clist.dtx
@@ -2,7 +2,7 @@
 %
 %% File: l3clist.dtx Copyright (C) 2004-2011 Frank Mittelbach,
 %%                                 The LaTeX3 project
-%%                             (C) 2012 The LaTeX3 Project
+%%                             (C) 2012,2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -37,7 +37,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3clist.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3clist.dtx 4414 2013-01-08 12:32:12Z bruno $
   {L3 Comma separated lists}
 %</driver|package>
 %<*driver>
@@ -690,14 +690,8 @@
 % \begin{macro}[pTF]{\clist_if_exist:N, \clist_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \clist_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \clist_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \clist_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \clist_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \clist_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \clist_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \clist_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \clist_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \clist_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \clist_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1454,10 +1448,12 @@
 %   {\clist_if_eq:NN, \clist_if_eq:Nc, \clist_if_eq:cN, \clist_if_eq:cc}
 %   Simple copies from the token list variable material.
 %    \begin{macrocode}
-\prg_new_eq_conditional:NNn \clist__if_eq:NN \tl_if_eq:NN { p , T , F , TF }
+%<*deprecated>
+\prg_new_eq_conditional:NNn \clist_if_eq:NN \tl_if_eq:NN { p , T , F , TF }
 \prg_new_eq_conditional:NNn \clist_if_eq:Nc \tl_if_eq:Nc { p , T , F , TF }
 \prg_new_eq_conditional:NNn \clist_if_eq:cN \tl_if_eq:cN { p , T , F , TF }
 \prg_new_eq_conditional:NNn \clist_if_eq:cc \tl_if_eq:cc { p , T , F , TF }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % 
@@ -1465,9 +1461,11 @@
 %  
 % \begin{macro}{\clist_length:N, \clist_length:c, \clist_length:n}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \clist_length:N \clist_count:N
 \cs_new_eq:NN \clist_length:n \clist_count:c
 \cs_new_eq:NN \clist_length:c \clist_count:n
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1475,8 +1473,10 @@
 %
 % \begin{macro}{\clist_use:N, \clist_use:c}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \clist_use:N \tl_use:N
 \cs_new_eq:NN \clist_use:c \tl_use:c
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3doc.dtx b/Master/texmf-dist/source/latex/l3kernel/l3doc.dtx
index f6734d35f46..073a979140e 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3doc.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3doc.dtx
@@ -78,7 +78,7 @@ Do not distribute a modified version of this file.
 %</driver|class>
 %
 %<*driver|class>
-\GetIdInfo$Id: l3doc.dtx 4267 2012-11-04 19:42:13Z joseph $
+\GetIdInfo$Id: l3doc.dtx 4442 2013-01-13 08:56:27Z bruno $
           {L3 Experimental documentation class}
 %</driver|class>
 %
@@ -1751,6 +1751,7 @@ Do not distribute a modified version of this file.
       {
         \seq_use:Nnnn \g_@@_tmpa_seq
           { \,~and~ } { \,,~ } { \,,~and~ }
+        \@.
       }
       { \seq_item:Nn \g_@@_tmpa_seq {1}\,~and~others. }
       
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3expan.dtx b/Master/texmf-dist/source/latex/l3kernel/l3expan.dtx
index d912433ee8d..739acab95e5 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3expan.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3expan.dtx
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3expan.dtx 4149 2012-08-28 10:50:40Z bruno $
+\GetIdInfo$Id: l3expan.dtx 4458 2013-02-03 15:49:37Z bruno $
   {L3 Argument expansion}
 %</driver|package>
 %<*driver>
@@ -78,6 +78,7 @@
 % variants.
 %
 % \section{Defining new variants}
+% \label{sec:defining-variants}
 %
 % The definition of variant forms for base functions may be necessary
 % when writing new functions or when applying a kernel function in a
@@ -193,22 +194,22 @@
 % specific expansion steps are needed, such as when using delimited
 % arguments, should the lower-level functions with |o| specifiers be employed.
 %
-% The |f| type is so special that it deserves an example.
-% Let's pretend we want to set |\aaa| equal to the control sequence
-% stemming from turning |b \l_tmpa_tl b| into a control
-% sequence. Furthermore we want to store the execution of it in a
+% The |f| type is so special that it deserves an example.  Let's pretend
+% we want to set the control sequence whose name is given by
+% |b \l_tmpa_tl b| equal to the list of tokens |\aaa a|.  Furthermore we
+% want to store the execution of it in a
 % \meta{tl~var}. In this example we assume |\l_tmpa_tl| contains
 % the text string |lur|. The straightforward approach is
 % \begin{quote}
-%   |\tl_set:No \l_tmpb_tl { \cs_set_eq:Nc \aaa { b \l_tmpa_tl b } }|
+%   |\tl_set:No \l_tmpb_tl { \tl_set:cn { b \l_tmpa_tl b } { \aaa a } }|
 % \end{quote}
 % Unfortunately this only puts
-% |\exp_args:NNc \cs_set_eq:NN \aaa {b \l_tmpa_tl b}| into |\l_tmpb_tl|
-% and not |\cs_set_eq:NN \aaa = \blurb| as we probably wanted. Using
-% \cs{tl_set:Nx} is not an option as that will die horribly. Instead
-% we can do a
+% |\exp_args:Nc \tl_set:Nn {b \l_tmpa_tl b} { \aaa a }| into
+% |\l_tmpb_tl| and not |\tl_set:Nn \blurb { \aaa a }| as we probably
+% wanted.  Using \cs{tl_set:Nx} is not an option as that will die
+% horribly.  Instead we can do a
 % \begin{quote}
-%   |\tl_set:Nf \l_tmpb_tl { \cs_set_eq:Nc \aaa { b \l_tmpa_tl b } }|
+%   |\tl_set:Nf \l_tmpb_tl { \tl_set:cn { b \l_tmpa_tl b } { \aaa a } }|
 % \end{quote}
 % which puts the desired result in |\l_tmpb_tl|. It requires
 % \cs{tl_set:Nf} to be defined as
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3file.dtx b/Master/texmf-dist/source/latex/l3kernel/l3file.dtx
index 416fc76cacb..67461fd01c9 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3file.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3file.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3file.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3file.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3file.dtx 4377 2012-12-20 11:13:29Z bruno $
+\GetIdInfo$Id: l3file.dtx 4446 2013-01-14 00:03:17Z bruno $
   {L3 File and I/O operations}
 %</driver|package>
 %<*driver>
@@ -192,6 +192,20 @@
 %   allocated to \meta{file name} until a \cs{ior_close:N} instruction
 %   is given or the \TeX{} run ends.
 % \end{function}
+% 
+% \begin{function}[added = 2013-01-12, TF]{\ior_open:Nn, \ior_open:cn}
+%   \begin{syntax}
+%     \cs{ior_open:NnTF} \meta{stream} \Arg{file name} \Arg{true code} \Arg{false code}
+%   \end{syntax}
+%   Opens \meta{file name} for reading using \meta{stream} as the
+%   control sequence for file access. If the \meta{stream} was already
+%   open it is closed before the new operation begins. The
+%   \meta{stream} is available for access immediately and will remain
+%   allocated to \meta{file name} until a \cs{ior_close:N} instruction
+%   is given or the \TeX{} run ends. The \meta{true code} is then inserted
+%   into the input stream. If the file is not found, no error is raised and
+%   the \meta{false code} is inserted into the input stream.
+% \end{function}
 %
 % \begin{function}[updated = 2012-02-09]{\iow_open:Nn, \iow_open:cn}
 %   \begin{syntax}
@@ -645,11 +659,11 @@
   { \@@_name_sanitize:nn {#1} { \@@_add_path:nN } }
 \cs_new_protected:Npn \@@_add_path:nN #1#2
   {
-    \__ior_open:Nn \g__file_internal_ior {#1}
-    \ior_if_eof:NTF \g__file_internal_ior
+    \__ior_open:Nn \g_@@_internal_ior {#1}
+    \ior_if_eof:NTF \g_@@_internal_ior
       { \@@_add_path_search:nN {#1} #2 }
       { \tl_set:Nn #2 {#1} }
-    \ior_close:N \g__file_internal_ior
+    \ior_close:N \g_@@_internal_ior
   }
 \cs_new_protected:Npn \@@_add_path_search:nN #1#2
   {
@@ -665,8 +679,8 @@
 %</package>
     \seq_map_inline:Nn \l_@@_search_path_seq
       {
-        \__ior_open:Nn \g__file_internal_ior { ##1 #1 }
-        \ior_if_eof:NF \g__file_internal_ior
+        \__ior_open:Nn \g_@@_internal_ior { ##1 #1 }
+        \ior_if_eof:NF \g_@@_internal_ior
           {
             \tl_set:Nx #2 { ##1 #1 }
             \seq_map_break:
@@ -824,71 +838,41 @@
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{\c_@@_streams_tl}
-%   The list of streams available, by number.
+% \begin{variable}{\g_@@_streams_seq}
+%   A list of the currently-available input streams to be used as a
+%   stack.  In format mode, all streams (from $0$ to~$15$) are
+%   available, while the package requests streams to \LaTeXe{} as they
+%   are needed (initially none are needed), so the starting point
+%   varies!
 %    \begin{macrocode}
-\tl_const:Nn \c_@@_streams_tl
-  {
-    \c_zero
-    \c_one
-    \c_two
-    \c_three
-    \c_four
-    \c_five
-    \c_six
-    \c_seven
-    \c_eight
-    \c_nine
-    \c_ten
-    \c_eleven
-    \c_twelve
-    \c_thirteen
-    \c_fourteen
-    \c_fifteen
-  }
+\seq_new:N \g_@@_streams_seq
+%<*initex>
+\seq_gset_split:Nnn \g_@@_streams_seq { , }
+  { 0 , 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 }
+%</initex>
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{\g_@@_streams_prop}
-%   The allocations for streams are stored in property lists, which
-%   are set up to have a \enquote{full} set of allocations from the start.
-%   In package mode, a few slots are always taken, so these are
-%   blocked off from use.
+% \begin{variable}{\l_@@_stream_tl}
+%   Used to recover the raw stream number from the stack.
 %    \begin{macrocode}
-\prop_new:N \g_@@_streams_prop
-%<*package>
-\prop_put:Nnn \g_@@_streams_prop { 0 } { LaTeX2e~reserved }
-%</package>
+\tl_new:N \l_@@_stream_tl
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{\l_@@_stream_int}
-%   Used to track the number allocated to the stream being created:
-%   this is taken from the property list but does alter.
+% \begin{variable}{\g_@@_streams_prop}
+%   The name of the file attached to each stream is tracked in a property
+%   list.
 %    \begin{macrocode}
-\int_new:N \l_@@_stream_int
+\prop_new:N \g_@@_streams_prop
+%<*package>
+\prop_gput:Nnn \g_@@_streams_prop { 0 } { LaTeX2e~reserved }
+%</package>
 %    \end{macrocode}
 % \end{variable}
 %
 % \subsubsection{Stream management}
 %
-% \begin{macro}[int]{\@@_new:N, \@@_new:c}
-%   The lowest level for stream management is actually creating raw \TeX{}
-%   streams. As these are very limited (even with \eTeX{}), this should not
-%   be addressed directly.
-%    \begin{macrocode}
-%<*initex>
-\__alloc_setup_type:nnn { ior } \c_zero \c_sixteen
-\cs_new_protected:Npn \@@_new:N #1
-  { \__alloc_reg:nNN { ior } \tex_chardef:D #1 }
-%</initex>
-%<*package>
-\cs_set_eq:NN \@@_new:N \newread
-%</package>
-\cs_generate_variant:Nn \@@_new:N { c }
-%    \end{macrocode}
-% \end{macro}
-%
 % \begin{macro}{\ior_new:N, \ior_new:c}
 %   Reserving a new stream is done by defining the name as equal to using the
 %   terminal.
@@ -897,27 +881,14 @@
 \cs_generate_variant:Nn \ior_new:N { c }
 %    \end{macrocode}
 % \end{macro}
-%
-% \begin{variable}{\g__file_internal_ior}
-%   Delayed from the \texttt{file} section so that the mechanisms are in place.
-%    \begin{macrocode}
-\ior_new:N \g__file_internal_ior
-%    \end{macrocode}
-% \end{variable}
-%
+% 
 % \begin{macro}{\ior_open:Nn, \ior_open:cn}
-% \begin{macro}[TF]{\ior_open:Nn}
 % \begin{macro}[aux]{\@@_open_aux:Nn}
-% \begin{macro}[aux]{\@@_open_aux:NnTF}
-% \begin{macro}[aux]{\@@_open:Nn, \@@_open:No}
-%   Opening a stream starts with a call to the closing function: this is
-%   safest. There is then a loop through the  allocation number list to find
-%   the first free stream number. When one is found the allocation can take
-%   place, the information can be stored and finally the file can actually be
-%   opened. Before any actual file operations there is a precaution against
-%   special characters in file names. There is an intermediate auxiliary to
-%   allow path addition, keeping the internal function fast and avoiding an
-%   infinite loop.
+%   Opening an input stream requires a bit of pre-processing. The file name
+%   is sanitized to deal with active characters, before an auxiliary adds a
+%   path and checks that the file really exists. If those two tests pass, then
+%   pass the information on to the lower-level function which deals with
+%   streams.
 %    \begin{macrocode}
 \cs_new_protected:Npn \ior_open:Nn #1#2
   { \__file_name_sanitize:nn {#2} { \@@_open_aux:Nn #1 } }
@@ -929,8 +900,20 @@
       { \__msg_kernel_error:nnx { kernel } { file-not-found } {#2} }
       { \@@_open:No #1 \l__file_internal_name_tl }
   }
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% 
+% \begin{macro}[TF]{\ior_open:Nn, \ior_open:cn}
+% \begin{macro}[aux]{\@@_open_aux:NnTF}
+%   Much the same idea for opening a read with a conditional, except the
+%   auxiliary function does not issue an error if the file is not found.
+%    \begin{macrocode}
 \prg_new_protected_conditional:Npnn \ior_open:Nn #1#2 { T , F , TF }
-  { \__file_name_sanitize:nn {#2} { \@@_open_aux:NnTF #1 } }
+  { \__file_name_sanitize:nn {#2} { \@@_open:NnTF #1 } }
+\cs_generate_variant:Nn \ior_open:NnT  { c }
+\cs_generate_variant:Nn \ior_open:NnF  { c }
+\cs_generate_variant:Nn \ior_open:NnTF { c }
 \cs_new_protected:Npn \@@_open_aux:NnTF #1#2
   {
     \file_add_path:nN {#2} \l__file_internal_name_tl
@@ -941,115 +924,63 @@
         \prg_return_true:
       }
   }
-\cs_generate_variant:Nn \ior_open:NnT  { c }
-\cs_generate_variant:Nn \ior_open:NnF  { c }
-\cs_generate_variant:Nn \ior_open:NnTF { c }
-\cs_new_protected:Npn \@@_open:Nn #1#2
-  {
-    \ior_close:N #1
-    \int_set_eq:NN \l_@@_stream_int \c_sixteen
-    \tl_map_function:NN \c_@@_streams_tl \@@_alloc:n
-    \int_compare:nNnTF \l_@@_stream_int = \c_sixteen
-      { \__msg_kernel_fatal:nn { kernel } { input-streams-exhausted } }
-      {
-        \@@_alloc:N #1
-        \prop_gput:NVn \g_@@_streams_prop \l_@@_stream_int {#2}
-        \tex_openin:D #1#2 \scan_stop:
-      }
-  }
-\cs_generate_variant:Nn \@@_open:Nn { No }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[aux]{\@@_alloc:n}
-%   See if a particular stream is available: the property list contains file
-%   names for streams in use, so any unused ones are for the taking.
+% 
+% \begin{macro}[int]{\@@_open:Nn, \@@_open:No}
+% \begin{macro}[aux]{\@@_open_stream:Nn}
+%   The stream allocation itself uses the fact that there is a list of all of
+%   those available, so allocation is simply a question of using the number at
+%   the top of the list. In package mode, life gets more complex as it's
+%   important to keep things in sync. That is done using a two-part approach:
+%   any streams that have already been taken up by \pkg{ior} but are now free
+%   are tracked, so we first try those. If that fails, ask \LaTeXe{} for a new
+%   stream and use that number (after a bit of conversion).
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_alloc:n #1
-  {
-    \prop_if_in:NnF \g_@@_streams_prop {#1}
-      {
-        \int_set:Nn \l_@@_stream_int {#1}
-        \tl_map_break:
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[aux]{\@@_alloc:N}
-% \begin{macro}[aux]{\@@_alloc:}
-% \begin{variable}{\g_@@_internal_ior}
-%   Allocating a raw stream is much easier in \IniTeX{} mode than for the
-%   package. For the format, all streams will be allocated by \pkg{l3file} and
-%   so there is a simple check to see if a raw stream is actually available. On
-%   the other hand, for the package there will be non-managed streams. So if
-%   the managed one is not open, a check is made to see if some other managed
-%   stream is available before deciding to open a new one. If a new one is
-%   needed, we get the number allocated by \LaTeXe{} to get \enquote{back on
-%   track} with allocation.
-%    \begin{macrocode}
-\ior_new:N \g_@@_internal_ior
-\cs_new_protected:Npn \@@_alloc:N #1
+\cs_new_protected:Npn \@@_open:Nn #1#2
   {
-    \cs_if_exist:cF { g_ior_ \int_use:N \l_@@_stream_int _ior }
-      {
-%<*package>
-        \@@_alloc:
-        \int_compare:nNnT \l_@@_stream_int = \c_sixteen
-          {
-            \@@_new:N \g_@@_internal_ior
-            \int_set:Nn \l_@@_stream_int { \g_@@_internal_ior }
-            \cs_gset_eq:cN
-              { g_ior_ \int_use:N \l_@@_stream_int _ior } \g_@@_internal_ior
-          }
-%</package>
+    \ior_close:N #1
+    \seq_gpop:NNTF \g_@@_streams_seq \l_@@_stream_tl
+      { \@@_open_stream:Nn #1 {#2} }
 %<*initex>
-        \@@_new:c { g_ior_ \int_use:N \l_@@_stream_int _ior }
+      { \__msg_kernel_fatal:nn { kernel } { input-streams-exhausted } }
 %</initex>
-      }
-    \cs_gset_eq:Nc #1 { g_ior_ \int_use:N \l_@@_stream_int _ior }
-  }
 %<*package>
-\cs_new_protected_nopar:Npn \@@_alloc:
-  {
-    \int_incr:N \l_@@_stream_int
-    \int_compare:nNnT \l_@@_stream_int < \c_sixteen
       {
-        \cs_if_exist:cTF { g_ior_ \int_use:N \l_@@_stream_int _ior }
-          {
-            \prop_if_in:NVT \g_@@_streams_prop \l_@@_stream_int
-              { \@@_alloc: }
-          }
-          { \@@_alloc: }
+        \newread #1
+        \tl_set:Nx \l_@@_stream_tl { \int_eval:n {#1} }
+        \@@_open_stream:Nn #1 {#2}
       }
-  }
 %</package>
+  }
+\cs_generate_variant:Nn \@@_open:Nn { No }
+\cs_new_protected:Npn \@@_open_stream:Nn #1#2
+  {
+    \tex_global:D \tex_chardef:D #1 = \l_@@_stream_tl \scan_stop:
+    \prop_gput:NVn \g_@@_streams_prop #1 {#2}
+    \tex_openin:D #1 #2 \scan_stop:
+  }
 %    \end{macrocode}
-% \end{variable}
 % \end{macro}
 % \end{macro}
 %
 % \begin{macro}{\ior_close:N, \ior_close:c}
-%   Closing a stream is not quite the reverse of opening one. First,
-%   the close operation is easier than the open one, and second as the
-%   stream is actually a number we can use it directly to show that the
-%   slot has been freed up.
+%   Closing a stream means getting rid of it at the \TeX{} level and
+%   removing from the various data structures.  Unless the name passed
+%   is an invalid stream number (outside the range $[0,15]$), it can be
+%   closed.  On the other hand, it only gets added to the stack if it
+%   was not already there, to avoid duplicates building up.
 %    \begin{macrocode}
 \cs_new_protected:Npn \ior_close:N #1
   {
-    \__chk_if_exist_cs:N #1
-    \int_compare:nNnF #1 < \c_zero
+    \int_compare:nT { \c_minus_one < #1 < \c_sixteen }
       {
-        \int_compare:nNnF #1 > \c_fifteen
-          {
-            \tex_closein:D #1
-            \prop_gremove:NV \g_@@_streams_prop #1
-            \cs_gset_eq:NN #1 \c_term_ior
-          }
+        \tex_closein:D #1
+        \prop_gremove:NV \g_@@_streams_prop #1
+        \seq_if_in:NVF \g_@@_streams_seq #1
+          { \seq_gpush:NV \g_@@_streams_seq #1 }
+        \cs_gset_eq:NN #1 \c_term_ior
       }
   }
 \cs_generate_variant:Nn \ior_close:N { c }
@@ -1135,6 +1066,13 @@
 %    \end{macrocode}
 % \end{macro}
 %
+% \begin{variable}{\g__file_internal_ior}
+%   Needed by the higher-level code, but cannot be created until here.
+%    \begin{macrocode}
+\ior_new:N \g__file_internal_ior
+%    \end{macrocode}
+% \end{variable}
+%
 % \subsection{Output operations}
 %
 %    \begin{macrocode}
@@ -1142,7 +1080,8 @@
 %    \end{macrocode}
 %
 % There is a lot of similarity here to the input operations, at least for
-% many of the basics. Thus quite a bit is copied from the earlier material.
+% many of the basics. Thus quite a bit is copied from the earlier material
+% with minor alterations.
 %
 % \subsubsection{Variables and constants}
 %
@@ -1156,11 +1095,22 @@
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{\c_@@_streams_tl}
-%   The list of streams available, by number: copied from the input
-%   operations.
+% \begin{variable}{\g_@@_streams_seq}
+%   A list of the currently-available input streams to be used as a stack.
+%   Things are done differently in format and package mode, so the starting
+%   point varies!
 %    \begin{macrocode}
-\cs_new_eq:NN \c_@@_streams_tl \c__ior_streams_tl
+\seq_new:N \g_@@_streams_seq
+%<*initex>
+\seq_gset_eq:NN \g_@@_streams_seq \g__ior_streams_seq
+%</initex>
+%    \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_stream_tl}
+%   Used to recover the raw stream number from the stack.
+%    \begin{macrocode}
+\tl_new:N \l_@@_stream_tl
 %    \end{macrocode}
 % \end{variable}
 %
@@ -1176,32 +1126,8 @@
 %    \end{macrocode}
 % \end{variable}
 %
-% \begin{variable}{\l_@@_stream_int}
-%   Used to track the number allocated to the stream being created:
-%   this is taken from the property list but does alter. The two allocation
-%   routines only need one register, so we save one here.
-%    \begin{macrocode}
-\cs_new_eq:NN \l_@@_stream_int \l__ior_stream_int
-%    \end{macrocode}
-% \end{variable}
-%
 % \subsection{Stream management}
 %
-% \begin{macro}[aux]{\@@_new:N, \@@_new:c}
-%   The same idea as for input, but with a separate set of functions.
-%    \begin{macrocode}
-%<*initex>
-\__alloc_setup_type:nnn { iow } \c_zero \c_sixteen
-\cs_new_protected:Npn \@@_new:N #1
-  { \__alloc_reg:nNN { iow } \tex_chardef:D #1 }
-%</initex>
-%<*package>
-\cs_set_eq:NN \@@_new:N \newwrite
-%</package>
-\cs_generate_variant:Nn \@@_new:N { c }
-%    \end{macrocode}
-% \end{macro}
-%
 % \begin{macro}{\iow_new:N, \iow_new:c}
 %   Reserving a new stream is done by defining the name as equal to writing
 %   to the terminal: odd but at least consistent.
@@ -1212,8 +1138,10 @@
 % \end{macro}
 %
 % \begin{macro}{\iow_open:Nn, \iow_open:cn}
-% \begin{macro}[aux]{\@@_open:Nn}
-%   The same idea as for reading, but without the path.
+% \begin{macro}[int]{\@@_open:Nn}
+% \begin{macro}[aux]{\@@_open_stream:Nn}
+%   The same idea as for reading, but without the path and without the need
+%   to allow for a conditional version.
 %    \begin{macrocode}
 \cs_new_protected:Npn \iow_open:Nn #1#2
   { \__file_name_sanitize:nn {#2} { \@@_open:Nn #1 } }
@@ -1221,78 +1149,28 @@
 \cs_new_protected:Npn \@@_open:Nn #1#2
   {
     \iow_close:N #1
-    \int_set_eq:NN \l_@@_stream_int \c_sixteen
-    \tl_map_function:NN \c_@@_streams_tl \@@_alloc:n
-    \int_compare:nNnTF \l_@@_stream_int = \c_sixteen
+    \seq_gpop:NNTF \g_@@_streams_seq \l_@@_stream_tl
+      { \@@_open_stream:Nn #1 {#2} }
+%<*initex>
       { \__msg_kernel_fatal:nn { kernel } { output-streams-exhausted } }
+%</initex>
+%<*package>
       {
-        \@@_alloc:N #1
-        \prop_gput:NVn \g_@@_streams_prop \l_@@_stream_int {#2}
-        \tex_immediate:D \tex_openout:D #1#2 \scan_stop:
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[aux]{\@@_alloc:n}
-%   Identical to the input routine, but with the appropriate names used
-%   (when \pkg{l3docstrip} has done it's job!).
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_alloc:n #1
-  {
-    \prop_if_in:NnF \g_@@_streams_prop {#1}
-      {
-        \int_set:Nn \l_@@_stream_int {#1}
-        \tl_map_break:
+        \newwrite #1
+        \tl_set:Nx \l_@@_stream_tl { \int_eval:n {#1} }
+        \@@_open_stream:Nn #1 {#2}
       }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}[aux]{\@@_alloc:N}
-% \begin{macro}[aux]{\@@_alloc:}
-% \begin{variable}{\g_@@_internal_iow}
-%   Exactly the same as for reading!
-%    \begin{macrocode}
-\iow_new:N \g_@@_internal_iow
-\cs_new_protected:Npn \@@_alloc:N #1
-  {
-    \cs_if_exist:cF { g_iow_ \int_use:N \l_@@_stream_int _iow }
-      {
-%<*package>
-        \@@_alloc:
-        \int_compare:nNnT \l_@@_stream_int = \c_sixteen
-          {
-            \@@_new:N \g_@@_internal_iow
-            \int_set:Nn \l_@@_stream_int { \g_@@_internal_iow }
-            \cs_gset_eq:cN
-              { g_iow_ \int_use:N \l_@@_stream_int _iow } \g_@@_internal_iow
-          }
 %</package>
-%<*initex>
-        \@@_new:c { g_iow_ \int_use:N \l_@@_stream_int _iow }
-%</initex>
-      }
-    \cs_gset_eq:Nc #1 { g_iow_ \int_use:N \l_@@_stream_int _iow }
   }
-%<*package>
-\cs_new_protected_nopar:Npn \@@_alloc:
+\cs_generate_variant:Nn \@@_open:Nn { No }
+\cs_new_protected:Npn \@@_open_stream:Nn #1#2
   {
-    \int_incr:N \l_@@_stream_int
-    \int_compare:nNnT \l_@@_stream_int < \c_sixteen
-      {
-        \cs_if_exist:cTF { g_iow_ \int_use:N \l_@@_stream_int _iow }
-          {
-            \prop_if_in:NVT \g_@@_streams_prop \l_@@_stream_int
-              { \@@_alloc: }
-          }
-          { \@@_alloc: }
-      }
+    \tex_global:D \tex_chardef:D #1 = \l_@@_stream_tl \scan_stop:
+    \prop_gput:NVn \g_@@_streams_prop #1 {#2}
+    \tex_immediate:D \tex_openout:D #1 #2 \scan_stop:
   }
-%</package>
 %    \end{macrocode}
-% \end{variable}
+% \end{macro}
 % \end{macro}
 % \end{macro}
 %
@@ -1304,15 +1182,13 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \iow_close:N #1
   {
-    \__chk_if_exist_cs:N #1
-    \int_compare:nNnF #1 < \c_zero
+    \int_compare:nT { \c_minus_one < #1 < \c_sixteen }
       {
-        \int_compare:nNnF #1 > \c_fifteen
-          {
-            \tex_immediate:D \tex_closeout:D #1
-            \prop_gremove:NV \g_@@_streams_prop #1
-            \cs_gset_eq:NN #1 \c_term_iow
-          }
+        \tex_immediate:D \tex_closeout:D #1
+        \prop_gremove:NV \g_@@_streams_prop #1
+        \seq_if_in:NVF \g_@@_streams_seq #1
+          { \seq_gpush:NV \g_@@_streams_seq #1 }
+        \cs_gset_eq:NN #1 \c_term_ior
       }
   }
 \cs_generate_variant:Nn \iow_close:N { c }
@@ -1809,8 +1685,10 @@
 % \begin{macro}{\iow_wrap:xnnnN}
 %   This was renamed and one unneed argument was removed.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_protected:Npn \iow_wrap:xnnnN #1#2#3#4#5
   { \iow_wrap:nnnN {#1} {#2} {#4} #5 }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1819,7 +1697,9 @@
 % \begin{variable}{\l_iow_line_length_int}
 %   Simple rename.  Here we copy the \TeX{} register.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \l_iow_line_length_int \l_iow_line_count_int
+%</deprecated>
 %    \end{macrocode}
 % \end{variable}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3format.ins b/Master/texmf-dist/source/latex/l3kernel/l3format.ins
new file mode 100644
index 00000000000..76fe0ee3e76
--- /dev/null
+++ b/Master/texmf-dist/source/latex/l3kernel/l3format.ins
@@ -0,0 +1,92 @@
+\iffalse meta-comment
+
+File l3format.ins Copyright (C) 2011,2012 The LaTeX3 Project
+
+It may be distributed and/or modified under the conditions of the
+LaTeX Project Public License (LPPL), either version 1.3c of this
+license or (at your option) any later version.  The latest version
+of this license is in the file
+
+   http://www.latex-project.org/lppl.txt
+
+This file is part of the "l3kernel bundle" (The Work in LPPL)
+and all files in that bundle must be distributed together.
+
+The released version of this bundle is available from CTAN.
+
+\fi
+
+\let\jobname\relax
+\input l3docstrip.dtx
+\askforoverwritefalse
+
+\preamble
+
+EXPERIMENTAL CODE
+
+Do not distribute this file without also distributing the
+source files specified above.
+
+Do not distribute a modified version of this file.
+
+\endpreamble
+% stop docstrip adding \endinput
+\postamble
+\endpostamble
+
+\keepsilent
+
+\generate
+  {
+  \file{l3format.ltx}
+    {
+        \from{l3bootstrap.dtx}  {initex}
+        \from{l3names.dtx}      {initex}
+        \from{l3basics.dtx}     {initex}
+        \from{l3expan.dtx}      {initex}
+        \from{l3tl.dtx}         {initex}
+        \from{l3seq.dtx}        {initex}
+        % ===== ===FORMAT ONLY =========
+        \from{l3alloc.dtx}      {initex}
+        % ==============================
+        \from{l3int.dtx}        {initex}
+        \from{l3quark.dtx}      {initex}
+        \from{l3prg.dtx}        {initex}
+        \from{l3clist.dtx}      {initex}
+        \from{l3token.dtx}      {initex}
+        \from{l3prop.dtx}       {initex}
+        \from{l3msg.dtx}        {initex}
+        \from{l3file.dtx}       {initex}
+        \from{l3skip.dtx}       {initex}
+        \from{l3keys.dtx}       {initex}
+        \from{l3fp.dtx}         {initex}
+        \from{l3fp-aux.dtx}     {initex}
+        \from{l3fp-traps.dtx}   {initex}
+        \from{l3fp-round.dtx}   {initex}
+        \from{l3fp-parse.dtx}   {initex}
+        \from{l3fp-logic.dtx}   {initex}
+        \from{l3fp-basics.dtx}  {initex}
+        \from{l3fp-extended.dtx}{initex}
+        \from{l3fp-expo.dtx}    {initex}
+        \from{l3fp-trig.dtx}    {initex}
+        \from{l3fp-convert.dtx} {initex}
+        \from{l3fp-assign.dtx}  {initex}
+        \from{l3fp-old.dtx}     {initex}
+        \from{l3box.dtx}        {initex}
+        \from{l3coffins.dtx}    {initex}
+        \from{l3color.dtx}      {initex}
+        \from{l3luatex.dtx}     {initex}
+        \from{l3candidates.dtx} {initex}
+        % ======== FORMAT ONLY =========
+        \from{l3final.dtx}      {initex}
+        % ==============================
+      }
+  }
+
+\generate{\file{l3dvips.ltx}    {\from{l3drivers.dtx}{initex,dvips}    }}
+\generate{\file{l3pdfmode.ltx}  {\from{l3drivers.dtx}{initex,pdfmode}  }}
+\generate{\file{l3xdvipdfmx.ltx}{\from{l3drivers.dtx}{initex,xdvipdfmx}}}
+
+\generate{\file{l3docstrip.tex}{\from{l3docstrip.dtx}{program}}}
+
+\endbatchfile
\ No newline at end of file
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3fp-logic.dtx b/Master/texmf-dist/source/latex/l3kernel/l3fp-logic.dtx
index edbe34ee82c..6c7991c4027 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3fp-logic.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3fp-logic.dtx
@@ -96,14 +96,8 @@
 % \begin{macro}[pTF]{\fp_if_exist:N, \fp_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \fp_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \fp_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \fp_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \fp_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \fp_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \fp_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \fp_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \fp_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \fp_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \fp_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3fp-traps.dtx b/Master/texmf-dist/source/latex/l3kernel/l3fp-traps.dtx
index ceb2840a810..1e00baa38da 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3fp-traps.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3fp-traps.dtx
@@ -36,7 +36,7 @@
 %
 %<*driver>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3fp-traps.dtx 4179 2012-08-31 15:54:18Z bruno $
+\GetIdInfo$Id: l3fp-traps.dtx 4428 2013-01-10 13:23:29Z bruno $
   {L3 Floating-point exception trapping}
 \documentclass[full]{l3doc}
 \begin{document}
@@ -91,7 +91,7 @@
 %   Function to turn a flag off.  Simply undefine it.
 %    \begin{macrocode}
 \cs_new_protected:Npn \fp_flag_off:n #1
-  { \cs_set_eq:cN { l_@@_ #1 _flag_token } \c_undefined:D }
+  { \cs_set_eq:cN { l_@@_ #1 _flag_token } \tex_undefined:D }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -128,10 +128,10 @@
 %   The \textsc{ieee} standard defines five exceptions.  We currently
 %   don't support the \enquote{inexact} exception.
 %    \begin{macrocode}
-\cs_new_eq:NN \l_@@_invalid_operation_flag_token \c_undefined:D
-\cs_new_eq:NN \l_@@_division_by_zero_flag_token \c_undefined:D
-\cs_new_eq:NN \l_@@_overflow_flag_token \c_undefined:D
-\cs_new_eq:NN \l_@@_underflow_flag_token \c_undefined:D
+\cs_new_eq:NN \l_@@_invalid_operation_flag_token \tex_undefined:D
+\cs_new_eq:NN \l_@@_division_by_zero_flag_token \tex_undefined:D
+\cs_new_eq:NN \l_@@_overflow_flag_token \tex_undefined:D
+\cs_new_eq:NN \l_@@_underflow_flag_token \tex_undefined:D
 %    \end{macrocode}
 % \end{variable}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3fp.dtx b/Master/texmf-dist/source/latex/l3kernel/l3fp.dtx
index e531e62e54e..09efdfdd58f 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3fp.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3fp.dtx
@@ -36,7 +36,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3fp.dtx 4305 2012-11-10 08:40:25Z joseph $
+\GetIdInfo$Id: l3fp.dtx 4449 2013-01-19 23:55:05Z bruno $
   {L3 Floating points}
 %</driver|package>
 %<*driver>
@@ -362,16 +362,18 @@
 %   case occurs exactly when one of the operands is \nan{}, and
 %   this relations is denoted by the symbol |?|.  The \texttt{nNn}
 %   functions support the \meta{relations} |<|, |=|, |>|, and |?|.  The
-%   \texttt{n} functions support as a \meta{relation} any combination of
-%   those four symbols, plus an optional leading |!| (which negates the
+%   \texttt{n} functions support as a \meta{relation} any non-empty string of
+%   those four symbols, plus optional leading |!| (which negate the
 %   \meta{relation}), with the restriction that the \meta{relation} may
 %   not start with |?|.  Common choices of \meta{relation} include |>=|
 %   (greater or equal), |!=| (not equal), |!?| (comparable).  Note that
 %   a \nan{} is distinct from any value, even another
-%   \nan{}, hence $x=x$ is not true for a \nan{}. Thus to
-%   test if a value is \nan{}, use
+%   \nan{}, hence $x=x$ is not true for a \nan{}.
+%   Since a \nan{} is not comparable to any floating point, to test if a
+%   value is \nan{}, one can use the following, where~$0$ is an
+%   arbitrary floating point.
 %   \begin{verbatim}
-%     \fp_compare:nNnTF { <value> } != { <value> }
+%     \fp_compare:nNnTF { <value> } ? { 0 }
 %       { } % <value> is nan
 %       { } % <value> is not nan
 %   \end{verbatim}
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3int.dtx b/Master/texmf-dist/source/latex/l3kernel/l3int.dtx
index e67616a2f7d..dcea709ebbc 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3int.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3int.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3int.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3int.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3int.dtx 4237 2012-09-26 10:18:58Z bruno $
+\GetIdInfo$Id: l3int.dtx 4444 2013-01-13 20:27:20Z bruno $
   {L3 Integers}
 %</driver|package>
 %<*driver>
@@ -300,16 +300,36 @@
 %   \end{center}
 % \end{function}
 %
-% \begin{function}[EXP,pTF]{\int_compare:n}
+% \begin{function}[updated = 2013-01-13, EXP, pTF]{\int_compare:n}
 %   \begin{syntax}
-%     \cs{int_compare_p:n} \{ \meta{intexpr_1} \meta{relation} \meta{intexpr_2} \} \\
+%     \cs{int_compare_p:n} \\
+%     ~~\{ \\
+%     ~~~~\meta{intexpr_1} \meta{relation_1} \\
+%     ~~~~\ldots{} \\
+%     ~~~~\meta{intexpr_N} \meta{relation_N} \\
+%     ~~~~\meta{intexpr_{N+1}} \\
+%     ~~\} \\
 %     \cs{int_compare:nTF}
-%     ~~\{ \meta{intexpr_1} \meta{relation} \meta{intexpr_2} \}
+%     ~~\{ \\
+%     ~~~~\meta{intexpr_1} \meta{relation_1} \\
+%     ~~~~\ldots{} \\
+%     ~~~~\meta{intexpr_N} \meta{relation_N} \\
+%     ~~~~\meta{intexpr_{N+1}} \\
+%     ~~\} \\
 %     ~~\Arg{true code} \Arg{false code}
 %   \end{syntax}
-%   This function first evaluates each of the \meta{integer expressions}
-%   as described for \cs{int_eval:n}. The two results are then
-%   compared using the \meta{relation}:
+%   This function evaluates the \meta{integer expressions} as described
+%   for \cs{int_eval:n} and compares consecutive result using the
+%   corresponding \meta{relation}, namely it compares \meta{intexpr_1}
+%   and \meta{intexpr_2} using the \meta{relation_1}, then
+%   \meta{intexpr_2} and \meta{intexpr_3} using the \meta{relation_2},
+%   until finally comparing \meta{intexpr_N} and \meta{intexpr_{N+1}}
+%   using the \meta{relation_N}.  The test yields \texttt{true} if all
+%   comparisons are \texttt{true}.  Each \meta{integer expression} is
+%   evaluated only once, and the evaluation is lazy, in the sense that
+%   if one comparison is \texttt{false}, then no other \meta{integer
+%     expression} is evaluated and no other comparison is performed.
+%   The \meta{relations} can be any of the following:
 %   \begin{center}
 %     \begin{tabular}{ll}
 %       Equal                    & |=| or |==| \\
@@ -413,35 +433,35 @@
 %   \texttt{false}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\int_do_until:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\int_do_until:nn}
 %   \begin{syntax}
-%      \cs{int_do_until:nn} \{ \meta{intexpr_1} \meta{relation} \meta{intexpr_2} \} \Arg{code}
+%      \cs{int_do_until:nn} \Arg{integer relation} \Arg{code}
 %   \end{syntax}
 %   Places the \meta{code} in the input stream for \TeX{} to process, and
-%   then evaluates the relationship between the two
-%   \meta{integer expressions} as described for \cs{int_compare:nTF}.
+%   then evaluates the \meta{integer relation}
+%   as described for \cs{int_compare:nTF}.
 %   If the test is \texttt{false} then the \meta{code} will be inserted
 %   into the input stream again and a loop will occur until the
 %   \meta{relation} is \texttt{true}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\int_do_while:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\int_do_while:nn}
 %   \begin{syntax}
-%      \cs{int_do_while:nn} \{ \meta{intexpr_1} \meta{relation} \meta{intexpr_2} \} \Arg{code}
+%      \cs{int_do_while:nn} \Arg{integer relation} \Arg{code}
 %   \end{syntax}
 %   Places the \meta{code} in the input stream for \TeX{} to process, and
-%   then evaluates the relationship between the two
-%   \meta{integer expressions} as described for \cs{int_compare:nTF}.
+%   then evaluates the \meta{integer relation}
+%   as described for \cs{int_compare:nTF}.
 %   If the test is \texttt{true} then the \meta{code} will be inserted
 %   into the input stream again and a loop will occur until the
 %   \meta{relation} is \texttt{false}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\int_until_do:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\int_until_do:nn}
 %   \begin{syntax}
-%      \cs{int_until_do:nn} \{ \meta{intexpr_1} \meta{relation} \meta{intexpr_2} \} \Arg{code}
+%      \cs{int_until_do:nn} \Arg{integer_relation} \Arg{code}
 %   \end{syntax}
-%   Evaluates the relationship between the two \meta{integer expressions}
+%   Evaluates the \meta{integer relation}
 %   as described for \cs{int_compare:nTF}, and then places the
 %   \meta{code} in the input stream if the \meta{relation} is
 %   \texttt{false}. After the \meta{code} has been processed by \TeX{} the
@@ -449,11 +469,11 @@
 %   \texttt{true}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\int_while_do:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\int_while_do:nn}
 %   \begin{syntax}
-%      \cs{int_while_do:nn} \{ \meta{intexpr_1} \meta{relation} \meta{intexpr_2} \} \Arg{code}
+%      \cs{int_while_do:nn} \Arg{integer relation} \Arg{code}
 %   \end{syntax}
-%   Evaluates the relationship between the two \meta{integer expressions}
+%   Evaluates the \meta{integer relation}
 %   as described for \cs{int_compare:nTF}, and then places the
 %   \meta{code} in the input stream if the \meta{relation} is
 %   \texttt{true}. After the \meta{code} has been processed by \TeX{} the
@@ -591,7 +611,7 @@
 %
 % \begin{function}[updated = 2011-09-17, EXP]{\int_to_hexadecimal:n}
 %   \begin{syntax}
-%     \cs{int_to_binary:n} \Arg{integer expression}
+%     \cs{int_to_hexadecimal:n} \Arg{integer expression}
 %   \end{syntax}
 %   Calculates the value of the \meta{integer expression} and places
 %   the hexadecimal (base~$16$) representation of the result in the
@@ -1167,14 +1187,8 @@
 % \begin{macro}[pTF]{\int_if_exist:N, \int_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \int_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \int_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \int_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \int_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \int_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \int_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \int_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \int_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \int_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \int_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1288,8 +1302,10 @@
     \__prg_compare_error:
   }
 \cs_new:Npn \__prg_compare_error:Nw
-    #1#2 \prg_return_true: \else: \prg_return_false: \fi:
+    #1#2 \q_stop
   {
+    { }
+    \c_zero \fi:
     \__msg_kernel_expandable_error:nnn
       { kernel } { unknown-comparison } {#1}
     \prg_return_false:
@@ -1298,9 +1314,11 @@
 % \end{macro}
 %
 % \begin{macro}[pTF, EXP]{\int_compare:n}
-% \begin{macro}[aux, EXP]{\@@_compare_aux:Nw, \@@_compare_aux:NNw}
+% \begin{macro}[aux, EXP]
+%   {\@@_compare:w, \@@_compare:Nw, \@@_compare:NNw, \@@_compare:nnN}
 % \begin{macro}[aux, EXP]
 %   {
+%     \@@_compare_end_=:NNw,
 %     \@@_compare_=:NNw,
 %     \@@_compare_<:NNw,
 %     \@@_compare_>:NNw,
@@ -1310,67 +1328,122 @@
 %     \@@_compare_>=:NNw
 %   }
 %   Comparison tests using a simple syntax where only one set of braces
-%   is required and additional operators such as |!=| and |>=| are
-%   supported.  We can start evaluating from the left using
-%   \cs{@@_eval:w}, and we know that since the relation symbols |<|,
-%   |>|, |=| and |!| are not allowed in such expressions, they will
-%   terminate the expression.  Therefore, we first let \TeX{} evaluate
-%   this left hand side of the (in)equality.  We also insert at that
-%   stage the end of the test: \cs{@@_eval_end:} will end the
-%   evaluation of the right-hand side.
+%   is required, additional operators such as |!=| and |>=| are
+%   supported, and multiple comparisons can be performed at once, for
+%   instance |0 < 5 <= 1|.  The idea is to loop through the argument,
+%   finding one operand at a time, and comparing it to the previous one.
+%   The looping auxiliary \cs{@@_compare:Nw} reads one \meta{operand}
+%   and one \meta{comparison} symbol, and leaves roughly
+%   \begin{quote}
+%     \meta{operand} \cs{prg_return_false:} \cs{fi:} \\
+%     \cs{reverse_if:N} \cs{if_int_compare:w} \meta{operand} \meta{comparison} \\
+%     \cs{@@_compare:Nw}
+%   \end{quote}
+%   in the input stream.  Each call to this auxiliary provides the
+%   second operand of the last call's \cs{if_int_compare:w}.  If one of
+%   the \meta{comparisons} is \texttt{false}, the \texttt{true} branch
+%   of the \TeX{} conditional is taken (because of \cs{reverse_if:N}),
+%   immediately returning \texttt{false} as the result of the test.
+%   There is no \TeX{} conditional waiting the first operand, so we add
+%   an \cs{if_false:} and expand by hand with \cs{@@_value:w}, thus
+%   skipping \cs{prg_return_false:} on the first iteration.
+%
+%   Before starting the loop, the first step is to make sure that there
+%   is at least one relation symbol.  We first let \TeX{} evaluate this
+%   left hand side of the (in)equality using \cs{@@_eval:w}.  Since the
+%   relation symbols |<|, |>|, |=| and |!| are not allowed in integer
+%   expressions, they will terminate it.  If the argument contains no
+%   relation symbol, \cs{__prg_compare_error:} is expanded,
+%   inserting~|=| and itself after an error.  In all cases,
+%   \cs{@@_compare:w} receives as its argument an integer, a relation
+%   symbol, and some more tokens.  We then setup the loop, which will be
+%   ended by the two odd-looking items |e| and |{=nd_}|, with a trailing
+%   \cs{q_stop} used to grab the entire argument when necessary.
 %    \begin{macrocode}
 \prg_new_conditional:Npnn \int_compare:n #1 { p , T , F , TF }
   {
-    \exp_after:wN \@@_compare_aux:Nw \int_use:N \@@_eval:w #1
-        \__prg_compare_error: \@@_eval_end:
-      \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
+    \exp_after:wN \@@_compare:w
+    \int_use:N \@@_eval:w #1 \__prg_compare_error:
+  }
+\cs_new:Npn \@@_compare:w #1 \__prg_compare_error:
+  {
+    \exp_after:wN \if_false: \@@_value:w
+      \@@_compare:Nw #1 e { = nd_ } \q_stop
   }
 %    \end{macrocode}
-%   We have just evaluated the left-hand side.  To access the relation
-%   symbol, we remove the number by applying \cs{@@_to_roman:w}, after
-%   making sure that the argument becomes non-positive: its roman
-%   numeral representation is then empty.  The \cs{@@_compare_aux:NNw}
-%   auxiliary then probes the first two tokens to determine the relation
-%   symbol, building a control sequence from it.  All the extended forms
-%   have an extra |=| hence the test for that as a second token.  If the
-%   relation symbol is unknown, then the control sequence is turned by
-%   \TeX{} into \cs{scan_stop:}, and \cs{__prg_compare_error:Nw}
-%   raises an error.
+%   The goal here is to find an \meta{operand} and a \meta{comparison}.
+%   The \meta{operand} is already evaluated, but we cannot yet grab it
+%   as an argument.  To access the following relation symbol, we remove
+%   the number by applying \cs{@@_to_roman:w}, after making sure that
+%   the argument becomes non-positive: its roman numeral representation
+%   is then empty.  Then probe the first two tokens with
+%   \cs{@@_compare:NNw} to determine the relation symbol, building a
+%   control sequence from it.  All the extended forms have an extra |=|
+%   hence the test for that as a second token.  If the relation symbol
+%   is unknown, then the control sequence is turned by \TeX{} into
+%   \cs{scan_stop:}, ignored thanks to \tn{unexpanded}, and
+%   \cs{__prg_compare_error:Nw} raises an error.
 %    \begin{macrocode}
-\cs_new:Npn \@@_compare_aux:Nw #1#2 \__prg_compare_error:
+\cs_new:Npn \@@_compare:Nw #1#2 \q_stop
   {
-    \exp_after:wN \@@_compare_aux:NNw
-      \@@_to_roman:w - 0 #2 ?? \q_mark
-    #1#2
+    \exp_after:wN \@@_compare:NNw
+      \@@_to_roman:w - 0 #2 \q_mark
+    #1#2 \q_stop
   }
-\cs_new:Npn \@@_compare_aux:NNw #1#2#3 \q_mark
+\cs_new:Npn \@@_compare:NNw #1#2#3 \q_mark
   {
+    \etex_unexpanded:D
     \use:c { @@_compare_  #1  \if_meaning:w = #2 =  \fi: :NNw }
       \__prg_compare_error:Nw #1
   }
 %    \end{macrocode}
+%   When the last \meta{operand} is seen, \cs{@@_compare:NNw} receives
+%   |e| and |=nd_| as arguments, hence calling
+%   \cs{@@_compare_end_=:NNw} to end the loop: return the result of the
+%   last comparison (involving the operand that we just found).  When a
+%   normal relation is found, the appropriate auxiliary calls
+%   \cs{@@_compare:nnN} where |#1| is \cs{if_int_compare:w} or
+%   \cs{reverse_if:N} \cs{if_int_compare:w}, |#2| is the \meta{operand},
+%   and |#3| is one of |<|, |=|, or~|>|.  As announced earlier, we leave
+%   the \meta{operand} for the previous conditional.  If this
+%   conditional is true the result of the test is known, so we remove
+%   all tokens and return \texttt{false}.  Otherwise, we apply the
+%   conditional |#1| to the \meta{operand} |#2| and the comparison |#3|,
+%   and call \cs{@@_compare:Nw} to look for additional operands, after
+%   evaluating the following expression.
+%    \begin{macrocode}
+\cs_new:cpn { @@_compare_end_=:NNw } #1#2#3 e #4 \q_stop
+  {
+    {#3} \exp_stop_f:
+    \prg_return_false: \else: \prg_return_true: \fi:
+  }
+\cs_new:Npn \@@_compare:nnN #1#2#3
+  {
+        {#2} \exp_stop_f:
+      \prg_return_false: \exp_after:wN \use_none_delimit_by_q_stop:w
+    \fi:
+    #1 #2 #3 \exp_after:wN \@@_compare:Nw \@@_value:w \@@_eval:w
+  }
+%    \end{macrocode}
 %   The actual comparisons are then simple function calls, using the
 %   relation as delimiter for a delimited argument and discarding
 %   \cs{__prg_compare_error:Nw} \meta{token} responsible for error
 %   detection.
 %    \begin{macrocode}
 \cs_new:cpn { @@_compare_=:NNw } #1#2#3 =
-  { \if_int_compare:w #3 = \@@_eval:w }
+  { \@@_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} = }
 \cs_new:cpn { @@_compare_<:NNw } #1#2#3 <
-  { \if_int_compare:w #3 < \@@_eval:w }
+  { \@@_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} < }
 \cs_new:cpn { @@_compare_>:NNw } #1#2#3 >
-  { \if_int_compare:w #3 > \@@_eval:w }
+  { \@@_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} > }
 \cs_new:cpn { @@_compare_==:NNw } #1#2#3 ==
-  { \if_int_compare:w #3 = \@@_eval:w }
+  { \@@_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} = }
 \cs_new:cpn { @@_compare_!=:NNw } #1#2#3 !=
-  { \reverse_if:N \if_int_compare:w #3 = \@@_eval:w }
+  { \@@_compare:nnN { \if_int_compare:w } {#3} = }
 \cs_new:cpn { @@_compare_<=:NNw } #1#2#3 <=
-  { \reverse_if:N \if_int_compare:w #3 > \@@_eval:w }
+  { \@@_compare:nnN { \if_int_compare:w } {#3} > }
 \cs_new:cpn { @@_compare_>=:NNw } #1#2#3 >=
-  { \reverse_if:N \if_int_compare:w #3 < \@@_eval:w }
+  { \@@_compare:nnN { \if_int_compare:w } {#3} < }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -2335,29 +2408,37 @@
 % \begin{macro}{\if_num:w}
 %   Deprecated 2012-05-30 for removal after 2012-11-30.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \if_num:w \if_int_compare:w
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
 % \begin{variable}{\l_tmpc_int}
 %   Deprecated 2012-07-04 for removal after 2012-12-31.
 %    \begin{macrocode}
+%<*deprecated>
 \int_new:N \l_tmpc_int
+%</deprecated>
 %    \end{macrocode}
 % \end{variable}
 %
 % \begin{macro}{\int_eval:w, \int_eval_end:}
 %   Deprecated 2012-07-13 for removal after 2012-12-31.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \int_eval:w    \@@_eval:w
 \cs_new_eq:NN \int_eval_end: \@@_eval_end:
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
 % \begin{macro}{\int_value:w}
 %   Deprecated 2012-07-14 for removal after 2012-12-31.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \int_value:w \@@_value:w
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3keys.dtx b/Master/texmf-dist/source/latex/l3kernel/l3keys.dtx
index b6a4cafb577..3d38853224a 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3keys.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3keys.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3keys.dtx Copyright (C) 2006-2012 The LaTeX3 Project
+%% File: l3keys.dtx Copyright (C) 2006-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3keys.dtx 4256 2012-11-02 08:47:41Z joseph $
+\GetIdInfo$Id: l3keys.dtx 4461 2013-02-24 18:55:17Z joseph $
   {L3 Experimental key-value interfaces}
 %</driver|package>
 %<*driver>
@@ -863,8 +863,7 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_split_key:n #1
   {
-    \str_if_eq_x:nnTF
-      { \exp_not:N \q_nil } { \exp_not:o { \use_none:nnn #1 \q_nil \q_nil } }
+    \quark_if_nil:oTF { \use_none:nnn #1 \q_nil \q_nil }
       { \tl_set:Nx \l_@@_key_tl { \exp_not:o { \use_ii:nnn #1 \q_nil } } }
       { \@@_split_key:w #1 \q_stop }
   }
@@ -1977,7 +1976,9 @@
 % Internal material for removal by 2012-12-31.
 % 
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \c_keys_code_root_tl \c__keys_code_root_tl
+%</deprecated>
 %    \end{macrocode}
 %
 %    \begin{macrocode}
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3msg.dtx b/Master/texmf-dist/source/latex/l3kernel/l3msg.dtx
index 3d72db5db51..9a10e278f2d 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3msg.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3msg.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3msg.dtx Copyright (C) 2009-2012 The LaTeX3 Project
+%% File: l3msg.dtx Copyright (C) 2009-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3msg.dtx 4212 2012-09-09 12:24:04Z bruno $
+\GetIdInfo$Id: l3msg.dtx 4412 2013-01-08 12:23:19Z joseph $
   {L3 Messages}
 %</driver|package>
 %<*driver>
@@ -2206,8 +2206,10 @@
 % \begin{macro}{\msg_newline:, \msg_two_newlines:}
 %   New lines are printed in the same way as for low-level file writing.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_nopar:Npn \msg_newline: { ^^J }
 \cs_new_nopar:Npn \msg_two_newlines: { ^^J ^^J }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % 
@@ -2215,9 +2217,11 @@
 % \begin{macro}{\msg_interrupt:xxx}
 %   These were all misnamed.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_generate_variant:Nn \msg_log:n { x }
 \cs_generate_variant:Nn \msg_term:n { x }
 \cs_generate_variant:Nn \msg_interrupt:nnn { xxx }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -2229,6 +2233,7 @@
 %   is cleared, and the various message functions are created
 %   to simply use the code stored for the message.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_protected:Npn \msg_class_set:nn #1#2
   {
     \cs_if_exist:cTF { @@_ #1 _code:nnnnnn }
@@ -2247,6 +2252,7 @@
     \cs_set_protected:cpx { msg_ #1 :nn } ##1##2
       { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} { } { } { } { } }
   }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3prg.dtx b/Master/texmf-dist/source/latex/l3kernel/l3prg.dtx
index 54db54f0f58..79fa7961ebd 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3prg.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3prg.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3prg.dtx Copyright (C) 2005-2012 The LaTeX3 Project
+%% File: l3prg.dtx Copyright (C) 2005-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3prg.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3prg.dtx 4459 2013-02-13 09:21:15Z will $
   {L3 Control structures}
 %</driver|package>
 %<*driver>
@@ -183,8 +183,8 @@
 % |\foo_if_bar:NNT| but not |\foo_if_bar:NNF| (because |F| is missing
 % from the \meta{conditions} list). The return statements take care of
 % resolving the remaining \cs{else:} and \cs{fi:} before returning the
-% state. There must be a return statement for each branch, failing to do
-% so will result in an error if that branch is executed.
+% state. There must be a return statement for each branch; failing to do
+% so will result in erroneous output if that branch is executed.
 %
 % \begin{function}{\prg_new_eq_conditional:NNn, \prg_set_eq_conditional:NNn}
 %   \begin{syntax}
@@ -203,9 +203,18 @@
 %     \cs{prg_return_true:}
 %     \cs{prg_return_false:}
 %   \end{syntax}
-%   These functions define the logical state at the end of a conditional.
-%   As such, they should appear within the code for a conditional
-%   statement generated by \cs{prg_set_conditional:Npnn}, \emph{etc}.
+%   These `return' functions define the logical state of a conditional statement.
+%   They appear within the code for a conditional
+%   function generated by \cs{prg_set_conditional:Npnn}, \emph{etc}, to indicate
+%   when a true or false branch has been taken.
+%   While they may appear multiple times each within the code of such conditionals,
+%   the execution of the conditional must result in the expansion of one of these
+%   two functions \emph{exactly once}.
+%
+%   The return functions trigger what is internally an f-expansion process to complete
+%   the evaluation of the conditional. Therefore, after \cs{prg_return_true:} or \cs{prg_return_false:}
+%   there must be no non-expandable material in the input stream for the remainder of
+%   the expansion of the conditional code. This includes other instances of either of these functions.
 % \end{function}
 %
 % \section{The boolean data type}
@@ -870,14 +879,8 @@
 % \begin{macro}[pTF]{\bool_if_exist:N, \bool_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \bool_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \bool_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \bool_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \bool_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \bool_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \bool_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \bool_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \bool_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \bool_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \bool_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1817,12 +1820,14 @@
 %   }
 %   Moved to more sensible modules.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \prg_case_int:nnn \int_case:nnn
 \cs_new_eq:NN \prg_case_str:nnn \str_case:nnn
 \cs_new_eq:NN \prg_case_str:onn \str_case:onn
 \cs_new_eq:NN \prg_case_str:xxn \str_case_x:nnn
 \cs_new_eq:NN \prg_case_tl:Nnn  \tl_case:Nnn
 \cs_new_eq:NN \prg_case_tl:cnn  \tl_case:cnn
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1834,9 +1839,11 @@
 %     \prg_stepwise_variable:nnnNn
 %   }
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \prg_stepwise_function:nnnN  \int_step_function:nnnN
 \cs_new_eq:NN \prg_stepwise_inline:nnnn    \int_step_inline:nnnn
 \cs_new_eq:NN \prg_stepwise_variable:nnnNn \int_step_variable:nnnNn
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3prop.dtx b/Master/texmf-dist/source/latex/l3kernel/l3prop.dtx
index d8bec5ee50d..3046ae59e8b 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3prop.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3prop.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3prop.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3prop.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3prop.dtx 4212 2012-09-09 12:24:04Z bruno $
+\GetIdInfo$Id: l3prop.dtx 4423 2013-01-09 00:05:30Z bruno $
   {L3 Property lists}
 %</driver|package>
 %<*driver>
@@ -245,7 +245,7 @@
 %   check that the \meta{property list} really is a property list variable.
 % \end{function}
 %
-% \begin{function}[EXP,pTF]{\prop_if_empty:N, \prop_if_empty:c}
+% \begin{function}[EXP, pTF]{\prop_if_empty:N, \prop_if_empty:c}
 %   \begin{syntax}
 %     \cs{prop_if_empty_p:N} \meta{property list}
 %     \cs{prop_if_empty:NTF} \meta{property list} \Arg{true code} \Arg{false code}
@@ -331,7 +331,7 @@
 %
 % \section{Mapping to property lists}
 %
-% \begin{function}[updated = 2012-06-29, rEXP]
+% \begin{function}[updated = 2013-01-08, rEXP]
 %   {\prop_map_function:NN, \prop_map_function:cN}
 %   \begin{syntax}
 %     \cs{prop_map_function:NN} \meta{property list} \meta{function}
@@ -343,7 +343,7 @@
 %   should not be relied upon.
 % \end{function}
 %
-% \begin{function}[updated = 2012-06-29]
+% \begin{function}[updated = 2013-01-08]
 %   {\prop_map_inline:Nn, \prop_map_inline:cn}
 %   \begin{syntax}
 %     \cs{prop_map_inline:Nn} \meta{property list} \Arg{inline function}
@@ -432,29 +432,39 @@
 %
 % \section{Internal property list functions}
 %
-% \begin{variable}{\q__prop}
-%   The internal token used to separate out property list entries, separating
-%   both the \meta{key} from the \meta{value} and also one entry from another.
+% \begin{variable}{\s__prop}
+%   The internal token used to separate out property list entries,
+%   surrounding each \meta{key}.
 % \end{variable}
 %
-% \begin{function}{\__prop_split:NnTF}
+% \begin{variable}{\l__prop_internal_tl}
+%   Token list used to store new key--value pairs to be inserted by
+%   functions of the \cs{prop_put:Nnn} family.
+% \end{variable}
+%
+% \begin{function}[updated = 2013-01-08]{\__prop_split:NnTF}
 %   \begin{syntax}
 %     \cs{__prop_split:NnTF} \meta{property list} \Arg{key} \Arg{true code} \Arg{false code}
 %   \end{syntax}
 %   Splits the \meta{property list} at the \meta{key}, giving three
-%   groups: the \meta{extract} of \meta{property list} before the
+%   token lists: the \meta{extract} of \meta{property list} before the
 %   \meta{key}, the \meta{value} associated with the \meta{key} and the
 %   \meta{extract} of the \meta{property list} after the \meta{value}.
-%   The first \meta{extract} retains the internal structure of a property
-%   list. The second is only missing the leading separator \cs{q__prop}.
-%   This ensures that the concatenation of the two \meta{extracts} is a
+%   Both \meta{extracts} retain the internal structure of a property
+%   list, and the concatenation of the two \meta{extracts} is a
 %   property list.
 %   If the \meta{key} is present in the \meta{property list} then the
-%   \meta{true code} is left in the input stream, followed by the three
-%   groups: thus the \meta{true code} should properly absorb three arguments.
+%   \meta{true code} is left in the input stream, with |#1|, |#2|, and
+%   |#3| replaced by the first \meta{extract}, the \meta{value}, and the
+%   second extract.
 %   If the \meta{key} is not present in the \meta{property list} then
 %   the \meta{false code} is left in the input stream, with no trailing
 %   material.
+%   Both \meta{true code} and \meta{false code} are used in the
+%   replacement text of a macro defined internally, hence macro
+%   parameter characters should be doubled, except |#1|, |#2|, and |#3|
+%   which stand in the \meta{true code} for the three extracts from the
+%   property list.
 %   The \meta{key} comparison takes place as described for \cs{str_if_eq:nn}.
 % \end{function}
 %
@@ -484,47 +494,51 @@
 %
 % A property list is a macro whose top-level expansion is for the form
 % \begin{quote}
-%   \cs{q_@@} \meta{key_1} \cs{q_@@} \Arg{value_1} \\
+%   \cs{s_@@} \meta{key_1} \cs{s_@@} \Arg{value_1} \\
 %   \ldots{} \\
-%   \cs{q_@@} \meta{key_n} \cs{q_@@} \Arg{value_n} \\
-%   \cs{q_@@}
+%   \cs{s_@@} \meta{key_n} \cs{s_@@} \Arg{value_n} \\
 % \end{quote}
-% where the trailing \cs{q_@@} is always present for performance
-% reasons: this means that empty property lists are not actually empty.
 %
-% \begin{macro}[int]{\q_@@}
-%   A private quark is used as a marker between entries.
+% \begin{macro}[int]{\s_@@}
+%   A private scan mark is used as a marker surrounding each key.
 %    \begin{macrocode}
-\quark_new:N \q_@@
+\__scan_new:N \s_@@
 %    \end{macrocode}
 % \end{macro}
 %
+% \begin{variable}{\l_@@_internal_tl}
+%   Token list used to store the new key--value pair inserted by
+%   \cs{prop_put:Nnn} and friends.
+%    \begin{macrocode}
+\tl_new:N \l_@@_internal_tl
+%    \end{macrocode}
+% \end{variable}
+%
 % \begin{variable}[tested = m3prop004]{\c_empty_prop}
-%   An empty prop contains exactly one \cs{q_@@}.
+%   An empty prop is an empty token list.
 %    \begin{macrocode}
-\tl_const:Nn \c_empty_prop { \q_@@ }
+\cs_new_eq:NN \c_empty_prop \c_empty_tl
 %    \end{macrocode}
 % \end{variable}
 %
 % \subsection{Allocation and initialisation}
 %
-% \begin{macro}[tested = m3prop001]{\prop_new:N,\prop_new:c}
-%   Internally, property lists are token lists, but an empty prop
-%   is not an empty tl, so we need to do things by hand.
+% \begin{macro}[tested = m3prop001]{\prop_new:N, \prop_new:c}
+%   Internally, property lists are just token lists.
 %    \begin{macrocode}
-\cs_new_protected:Npn \prop_new:N #1 { \cs_new_eq:NN  #1  \c_empty_prop }
-\cs_new_protected:Npn \prop_new:c #1 { \cs_new_eq:cN {#1} \c_empty_prop }
+\cs_new_eq:NN \prop_new:N \tl_new:N
+\cs_new_eq:NN \prop_new:c \tl_new:c
 %    \end{macrocode}
 % \end{macro}
 %
 % \begin{macro}[tested = m3prop001]{\prop_clear:N, \prop_clear:c}
 % \begin{macro}[tested = m3prop001]{\prop_gclear:N, \prop_gclear:c}
-%   The same idea for  clearing
+%   The same idea for clearing.
 %    \begin{macrocode}
-\cs_new_protected:Npn \prop_clear:N #1  { \cs_set_eq:NN   #1  \c_empty_prop }
-\cs_generate_variant:Nn \prop_clear:N { c }
-\cs_new_protected:Npn \prop_gclear:N #1 { \cs_gset_eq:NN  #1  \c_empty_prop }
-\cs_generate_variant:Nn \prop_gclear:N { c }
+\cs_new_eq:NN \prop_clear:N  \tl_clear:N
+\cs_new_eq:NN \prop_clear:c  \tl_clear:c
+\cs_new_eq:NN \prop_gclear:N \tl_gclear:N
+\cs_new_eq:NN \prop_gclear:c \tl_gclear:c
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -533,12 +547,10 @@
 % \begin{macro}[tested = m3prop001]{\prop_gclear_new:N, \prop_gclear_new:c}
 %   Once again a simple copy from the token list functions.
 %    \begin{macrocode}
-\cs_new_protected:Npn \prop_clear_new:N #1
-  { \prop_if_exist:NTF #1 { \prop_clear:N #1 } { \prop_new:N #1 } }
-\cs_generate_variant:Nn \prop_clear_new:N { c }
-\cs_new_protected:Npn \prop_gclear_new:N #1
-  { \prop_if_exist:NTF #1 { \prop_gclear:N #1 } { \prop_new:N #1 } }
-\cs_generate_variant:Nn \prop_gclear_new:N { c }
+\cs_new_eq:NN \prop_clear_new:N  \tl_clear_new:N
+\cs_new_eq:NN \prop_clear_new:c  \tl_clear_new:c
+\cs_new_eq:NN \prop_gclear_new:N \tl_gclear_new:N
+\cs_new_eq:NN \prop_gclear_new:c \tl_gclear_new:c
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -577,67 +589,69 @@
 %
 % \begin{macro}[int]{\@@_split:NnTF}
 % \begin{macro}[aux]{\@@_split_aux:NnTF}
-% \begin{macro}[aux]{\@@_split_aux:nnnn}
-% \begin{macro}[aux]{\@@_split_aux:w}
+% \begin{macro}[aux, EXP]{\@@_split_aux:w}
 %   This function is used by most of the module, and hence must be fast.
-%   The aim here is to split a property list at a given key into the part
-%   before the key--value pair, the value associated with the key and the part
-%   after the key--value pair. To do this, the key is first detokenized (to
-%   avoid repeatedly doing this), then a delimited function is constructed to
-%   match the key. It will match \cs{q_@@} \meta{detokenized key} \cs{q_@@}
-%   \Arg{value} \meta{extra argument}, effectively separating an
-%   \meta{extract_1} before the key in the property list and an \meta{extract_2}
-%   after the key.
-%
-%   If the key is present in the property list, then \meta{extra argument}
-%   is simply \cs{q_@@}, and \cs{@@_split_aux:nnnn} will gobble this
-%   and the false branch (|#4|), leaving the correct code on the input
-%   stream. More precisely, it leaves the user code (true branch), followed
-%   by three groups, \Arg{extract_1} \Arg{value} \Arg{extract_2}.
-%   In order for \meta{extract_1}\meta{extract_2} to be a well-formed
-%   property list, \meta{extract_1} has a leading and trailing \cs{q_@@},
-%   retaining exactly the structure of a property list, while \meta{extract_2}
-%   omits the leading \cs{q_@@}.
-%
-%   If the key is not there, then \meta{extra argument} is |?|
-%   \cs{use_ii:nn} |{ }|, and \cs{@@_split_aux:nnnn} |?| \cs{use_ii:nn}
-%   |{ }| removes the three brace groups that just follow.  Then
-%   \cs{use_ii:nn} removes the true branch, leaving the false branch,
-%   with no trailing material.
+%   It receives a \meta{property list}, a \meta{key}, a \meta{true code}
+%   and a \meta{false code}.  The aim is to split the \meta{property
+%     list} at the given \meta{key} into the \meta{extract_1} before the
+%   key--value pair, the \meta{value} associated with the \meta{key} and
+%   the \meta{extract_2} after the key--value pair.  This is done using
+%   a delimited function, whose definition is as follows, where the
+%   \meta{key} is turned into a string.
+%   \begin{quote}
+%     \cs{cs_set:Npn} \cs{@@_split_aux:w} |#1| \\
+%     \quad \cs{s_@@} \meta{key} \cs{s_@@} |#2| \\
+%     \quad |#3| \cs{q_mark} |#4| |#5| \cs{q_stop} \\
+%     \quad |{| |#4| \Arg{true code} \Arg{false code} |}|
+%   \end{quote}
+%
+%   If the \meta{key} is present in the property list,
+%   \cs{@@_split_aux:w}'s |#1| is the part before the \meta{key}, |#2|
+%   is the \meta{value}, |#3| is the part after the \meta{key}, |#4| is
+%   \cs{use_i:nn}, and |#5| is additional tokens that we do not care
+%   about.  The \meta{true code} is left in the input stream, and can
+%   use the parameters |#1|, |#2|, |#3| for the three parts of the
+%   property list as desired.
+%
+%   If the \meta{key} is not there, then the \meta{function} is
+%   \cs{use_ii:nn}, which keeps the \meta{false code}.
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_split:NnTF #1#2
   { \exp_args:NNo \@@_split_aux:NnTF #1 { \tl_to_str:n {#2} } }
-\cs_new_protected:Npn \@@_split_aux:NnTF #1#2
+\cs_new_protected:Npn \@@_split_aux:NnTF #1#2#3#4
   {
-    \cs_set_protected:Npn \@@_split_aux:w
-      ##1 \q_@@ #2 \q_@@ ##2 ##3 ##4 \q_mark ##5 \q_stop
-      { \@@_split_aux:nnnn ##3 { {##1 \q_@@ } {##2} {##4} } }
-    \exp_after:wN \@@_split_aux:w #1 \q_mark
-         \q_@@ #2 \q_@@ { } { ? \use_ii:nn { } } \q_mark \q_stop
+    \cs_set:Npn \@@_split_aux:w ##1
+      \s_@@ #2 \s_@@ ##2 ##3 \q_mark ##4 ##5 \q_stop
+      { ##4 {#3} {#4} }
+    \exp_after:wN \@@_split_aux:w #1 \q_mark \use_i:nn
+      \s_@@ #2 \s_@@ { } \q_mark \use_ii:nn \q_stop
   }
-\cs_new:Npn \@@_split_aux:nnnn #1#2#3#4 { #3 #2 }
-\cs_new_protected:Npn \@@_split_aux:w { }
+\cs_new:Npn \@@_split_aux:w { }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
 % \begin{macro}[tested = m3prop002]
 %   {\prop_remove:Nn, \prop_remove:NV, \prop_remove:cn, \prop_remove:cV}
 % \begin{macro}[tested = m3prop002]
 %   {\prop_gremove:Nn, \prop_gremove:NV, \prop_gremove:cn, \prop_gremove:cV}
-% \begin{macro}[aux]{\@@_remove:NNnnn}
 %   Deleting from a property starts by splitting the list.
 %   If the key is present in the property list, the returned value is ignored.
 %   If the key is missing, nothing happens.
 %    \begin{macrocode}
 \cs_new_protected:Npn \prop_remove:Nn #1#2
-  { \@@_split:NnTF #1 {#2} { \@@_remove:NNnnn \tl_set:Nn #1 } { } }
+  {
+    \@@_split:NnTF #1 {#2}
+      { \tl_set:Nn #1 { ##1 ##3 } }
+      { }
+  }
 \cs_new_protected:Npn \prop_gremove:Nn #1#2
-  { \@@_split:NnTF #1 {#2} { \@@_remove:NNnnn \tl_gset:Nn #1 } { } }
-\cs_new_protected:Npn \@@_remove:NNnnn #1#2#3#4#5
-  { #1 #2 { #3 #5 } }
+  {
+    \@@_split:NnTF #1 {#2}
+      { \tl_gset:Nn #1 { ##1 ##3 } }
+      { }
+  }
 \cs_generate_variant:Nn \prop_remove:Nn  {     NV }
 \cs_generate_variant:Nn \prop_remove:Nn  { c , cV }
 \cs_generate_variant:Nn \prop_gremove:Nn {     NV }
@@ -645,14 +659,12 @@
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
 % \begin{macro}[tested = m3prop002]
 %   {
 %     \prop_get:NnN, \prop_get:NVN, \prop_get:NoN,
 %     \prop_get:cnN, \prop_get:cVN, \prop_get:coN
 %   }
-% \begin{macro}[aux]{\@@_get:Nnnn}
 %   Getting an item from a list is very easy: after splitting,
 %   if the key is in the property list, just set the token list variable
 %   to the return value, otherwise to \cs{q_no_value}.
@@ -660,22 +672,18 @@
 \cs_new_protected:Npn \prop_get:NnN #1#2#3
   {
     \@@_split:NnTF #1 {#2}
-      { \@@_get:Nnnn #3 }
+      { \tl_set:Nn #3 {##2} }
       { \tl_set:Nn #3 { \q_no_value } }
   }
-\cs_new_protected:Npn \@@_get:Nnnn #1#2#3#4
-  { \tl_set:Nn #1 {#3} }
 \cs_generate_variant:Nn \prop_get:NnN {     NV , No }
 \cs_generate_variant:Nn \prop_get:NnN { c , cV , co }
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
 %
 % \begin{macro}[tested = m3prop002]
 %   {\prop_pop:NnN, \prop_pop:NoN, \prop_pop:cnN, \prop_pop:coN}
 % \begin{macro}[tested = m3prop002]
 %   {\prop_gpop:NnN, \prop_gpop:NoN, \prop_gpop:cnN, \prop_gpop:coN}
-% \begin{macro}[aux]{\@@_pop:NNNnnn}
 %   Popping a value also starts by doing the split.
 %   If the key is present, save the value in the token list and update the
 %   property list as when deleting.
@@ -684,20 +692,21 @@
 \cs_new_protected:Npn \prop_pop:NnN #1#2#3
   {
     \@@_split:NnTF #1 {#2}
-      { \@@_pop:NNNnnn \tl_set:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_set:Nn #1 { ##1 ##3 }
+      }
       { \tl_set:Nn #3 { \q_no_value } }
   }
 \cs_new_protected:Npn \prop_gpop:NnN #1#2#3
   {
     \@@_split:NnTF #1 {#2}
-      { \@@_pop:NNNnnn \tl_gset:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_gset:Nn #1 { ##1 ##3 }
+      }
       { \tl_set:Nn #3 { \q_no_value } }
   }
-\cs_new_protected:Npn \@@_pop:NNNnnn #1#2#3#4#5#6
-  {
-    \tl_set:Nn #3 {#5}
-    #1 #2 { #4 #6 }
-  }
 \cs_generate_variant:Nn \prop_pop:NnN  {     No }
 \cs_generate_variant:Nn \prop_pop:NnN  { c , co }
 \cs_generate_variant:Nn \prop_gpop:NnN {     No }
@@ -705,11 +714,9 @@
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
-% \end{macro}
 %
 % \begin{macro}[TF, tested = m3prop004]
 %   {\prop_pop:NnN, \prop_pop:cnN, \prop_gpop:NnN, \prop_gpop:cnN}
-% \begin{macro}[aux]{\@@_pop_true:NNNnnn}
 %   Popping an item from a property list, keeping track of whether
 %   the key was present or not, is implemented as a conditional.
 %   If the key was missing, neither the property list, nor the token
@@ -719,21 +726,23 @@
 \prg_new_protected_conditional:Npnn \prop_pop:NnN #1#2#3 { T , F , TF }
   {
     \@@_split:NnTF #1 {#2}
-      { \@@_pop_true:NNNnnn \tl_set:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_set:Nn #1 { ##1 ##3 }
+        \prg_return_true:
+      }
       { \prg_return_false: }
   }
 \prg_new_protected_conditional:Npnn \prop_gpop:NnN #1#2#3 { T , F , TF }
   {
     \@@_split:NnTF #1 {#2}
-      { \@@_pop_true:NNNnnn \tl_gset:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_gset:Nn #1 { ##1 ##3 }
+        \prg_return_true:
+      }
       { \prg_return_false: }
   }
-\cs_new_protected:Npn \@@_pop_true:NNNnnn #1#2#3#4#5#6
-  {
-    \tl_set:Nn #3 {#5}
-    #1 #2 { #4 #6 }
-    \prg_return_true:
-  }
 \cs_generate_variant:Nn \prop_pop:NnNT   { c }
 \cs_generate_variant:Nn \prop_pop:NnNF   { c }
 \cs_generate_variant:Nn \prop_pop:NnNTF  { c }
@@ -742,7 +751,6 @@
 \cs_generate_variant:Nn \prop_gpop:NnNTF { c }
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
 %
 % \begin{macro}[tested = m3prop002]
 %   {
@@ -758,32 +766,31 @@
 %     \prop_gput:cnn, \prop_gput:cnV, \prop_gput:cno, \prop_gput:cnx,
 %     \prop_gput:cVn, \prop_gput:cVV, \prop_gput:con, \prop_gput:coo
 %   }
-% \begin{macro}[aux]{\@@_put:NNNnn, \@@_put:NNnnnnn}
-%   Putting a key--value pair in a property list starts by splitting to
-%   remove any existing value.  If the \meta{key} was absent, append the
-%   new key--value pair.  Otherwise, the property list is reconstructed
-%   from the two remaining parts |#5| and |#7|, and the updated entry.
-%   The updated entry is placed at the same spot as the original
-%   \meta{key} in the property list, preserving the order of entries.
+% \begin{macro}[aux]{\@@_put:NNNnn}
+%   Since the branches of \cs{@@_split:NnTF} are used as the replacement
+%   text of an internal macro, and since the \meta{key} and new
+%   \meta{value} may contain arbitrary tokens, it is not safe to include
+%   them in the argument of \cs{@@_split:NnTF}.  We thus start by
+%   storing in \cs{l_@@_internal_tl} tokens which (after
+%   \texttt{x}-expansion) encode the key--value pair.  This variable can
+%   safely be used in \cs{@@_split:NnTF}.  If the \meta{key} was absent,
+%   append the new key--value to the list.  Otherwise concatenate the
+%   extracts |##1| and |##3| with the new key--value pair
+%   \cs{l_@@_internal_tl}.  The updated entry is placed at the same spot
+%   as the original \meta{key} in the property list, preserving the
+%   order of entries.
 %    \begin{macrocode}
-\cs_new_protected:Npn \prop_put:Nnn
+\cs_new_protected_nopar:Npn \prop_put:Nnn
   { \@@_put:NNNnn \tl_set:Nx \tl_put_right:Nx }
-\cs_new_protected:Npn \prop_gput:Nnn
+\cs_new_protected_nopar:Npn \prop_gput:Nnn
   { \@@_put:NNNnn \tl_gset:Nx \tl_gput_right:Nx }
 \cs_new_protected:Npn \@@_put:NNNnn #1#2#3#4#5
   {
+    \tl_set:Nn \l_@@_internal_tl
+      { \s_@@ \tl_to_str:n {#4} \s_@@ { \exp_not:n {#5} } }
     \@@_split:NnTF #3 {#4}
-      { \@@_put:NNnnnnn #1 #3 {#4} {#5} }
-      { #2 #3 { \tl_to_str:n {#4} \exp_not:n { \q_@@ {#5} \q_@@ } } }
-  }
-\cs_new_protected:Npn \@@_put:NNnnnnn #1#2#3#4#5#6#7
-  {
-    #1 #2
-      {
-        \exp_not:n {#5}
-        \tl_to_str:n {#3} \exp_not:n { \q_@@ {#4} \q_@@ }
-        \exp_not:n {#7}
-      }
+      { #1 #3 { \exp_not:n {##1} \l_@@_internal_tl \exp_not:n {##3} } }
+      { #2 #3 { \l_@@_internal_tl } }
   }
 \cs_generate_variant:Nn \prop_put:Nnn
   {     NnV , Nno , Nnx , NV , NVV , No , Noo }
@@ -814,12 +821,11 @@
   { \@@_put_if_new:NNnn \tl_gput_right:Nx }
 \cs_new_protected:Npn \@@_put_if_new:NNnn #1#2#3#4
   {
+    \tl_set:Nn \l_@@_internal_tl
+      { \s_@@ \tl_to_str:n {#3} \s_@@ \exp_not:n { {#4} } }
     \@@_split:NnTF #2 {#3}
-      { \use_none:nnn }
-      {
-        #1 #2
-          { \tl_to_str:n {#3} \exp_not:n { \q_@@ {#4} \q_@@ } }
-      }
+      { }
+      { #1 #2 { \l_@@_internal_tl } }
   }
 \cs_generate_variant:Nn \prop_put_if_new:Nnn  { c }
 \cs_generate_variant:Nn \prop_gput_if_new:Nnn { c }
@@ -833,32 +839,18 @@
 % \begin{macro}[pTF, tested = m3prop004]{\prop_if_exist:N, \prop_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \prop_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \prop_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \prop_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \prop_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \prop_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \prop_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \prop_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \prop_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \prop_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \prop_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
 % \begin{macro}[pTF, tested = m3prop003]{\prop_if_empty:N, \prop_if_empty:c}
-%   The test here uses \cs{c_empty_prop} as it is not really empty!
+%   Same test as for token lists.
 %    \begin{macrocode}
-\prg_new_conditional:Npnn \prop_if_empty:N #1 { p, T , F , TF }
-  {
-    \if_meaning:w #1 \c_empty_prop
-      \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
-  }
-\cs_generate_variant:Nn \prop_if_empty_p:N {c}
-\cs_generate_variant:Nn \prop_if_empty:NTF {c}
-\cs_generate_variant:Nn \prop_if_empty:NT  {c}
-\cs_generate_variant:Nn \prop_if_empty:NF  {c}
+\prg_new_eq_conditional:NNn \prop_if_empty:N \tl_if_empty:N
+  { p , T , F , TF }
+\prg_new_eq_conditional:NNn \prop_if_empty:c \tl_if_empty:c
+  { p , T , F , TF }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -885,12 +877,12 @@
 %   but \cs{@@_split:NnTF} is non-expandable.
 %
 %   Instead, the key is compared to each key in turn using \cs{str_if_eq_x:nn},
-%   which is expandable. To terminate the mapping, we add the key that
-%   is search for at the end of the property list. This second
+%   which is expandable. To terminate the mapping, we append to the property
+%   list the key that is searched for. This second
 %   \cs{tl_to_str:n} is not expanded at the start, but only when included
 %   in the \cs{str_if_eq_x:nn}. It cannot make the breaking mechanism choke,
 %   because the arbitrary token list material is enclosed in braces.
-%   When ending, we test the next token: it is either \cs{q_@@}
+%   When ending, we test the next token: it is either \cs{s_@@}
 %   or \cs{q_recursion_tail} in the case of a missing key.
 %   Here, \cs{prop_map_function:NN} is not sufficient for the mapping,
 %   since it can only map a single token, and cannot carry the key that
@@ -900,11 +892,11 @@
   {
     \exp_last_unbraced:Noo \@@_if_in:nwn
       { \tl_to_str:n {#2} } #1
-      \tl_to_str:n {#2} \q_@@ { }
-    \q_recursion_tail % could be any cs != \q_@@
+      \s_@@ \tl_to_str:n {#2} \s_@@ { }
+    \q_recursion_tail
     \__prg_break_point:
   }
-\cs_new:Npn \@@_if_in:nwn #1 \q_@@ #2 \q_@@ #3
+\cs_new:Npn \@@_if_in:nwn #1 \s_@@ #2 \s_@@ #3
   {
     \str_if_eq_x:nnTF {#1} {#2}
       { \@@_if_in:N }
@@ -912,7 +904,7 @@
   }
 \cs_new:Npn \@@_if_in:N #1
   {
-    \if_meaning:w \q_@@ #1
+    \if_meaning:w \s_@@ #1
       \prg_return_true:
     \else:
       \prg_return_false:
@@ -938,7 +930,6 @@
 %     \prop_get:NnN, \prop_get:NVN, \prop_get:NoN,
 %     \prop_get:cnN, \prop_get:cVN, \prop_get:coN
 %   }
-% \begin{macro}[aux]{\@@_get_true:Nnnn}
 %   Getting the value corresponding to a key, keeping track of whether
 %   the key was present or not, is implemented as a conditional (with
 %   side effects). If the key was absent, the token list is not altered.
@@ -946,14 +937,12 @@
 \prg_new_protected_conditional:Npnn \prop_get:NnN #1#2#3 { T , F , TF }
   {
     \@@_split:NnTF #1 {#2}
-      { \@@_get_true:Nnnn #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \prg_return_true:
+      }
       { \prg_return_false: }
   }
-\cs_new_protected:Npn \@@_get_true:Nnnn #1#2#3#4
-  {
-    \tl_set:Nn #1 {#3}
-    \prg_return_true:
-  }
 \cs_generate_variant:Nn \prop_get:NnNT  {     NV , No }
 \cs_generate_variant:Nn \prop_get:NnNF  {     NV , No }
 \cs_generate_variant:Nn \prop_get:NnNTF {     NV , No }
@@ -962,7 +951,6 @@
 \cs_generate_variant:Nn \prop_get:NnNTF { c , cV , co }
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
 %
 % \subsection{Mapping to property lists}
 %
@@ -972,19 +960,24 @@
 %     \prop_map_function:cN, \prop_map_function:cc
 %   }
 % \begin{macro}[aux]{\@@_map_function:Nwn}
-%   The fastest way to do a recursion here would be to use an
+%   The fastest way to do a recursion here is to use an
 %   \cs{if_meaning:w} test: the keys are strings, and thus
 %   cannot match the marker \cs{q_recursion_tail}.
+%   A special case to note is when the key |#2| is empty:
+%   then \cs{q_recursion_tail} is compared to \cs{exp_after:wN},
+%   also different.
 %    \begin{macrocode}
 \cs_new:Npn \prop_map_function:NN #1#2
   {
     \exp_last_unbraced:NNo \@@_map_function:Nwn #2
-      #1 \q_recursion_tail \q_@@ { }
+      #1 \s_@@ \q_recursion_tail \s_@@ { }
     \__prg_break_point:Nn \prop_map_break: { }
   }
-\cs_new:Npn \@@_map_function:Nwn #1 \q_@@ #2 \q_@@ #3
+\cs_new:Npn \@@_map_function:Nwn #1 \s_@@ #2 \s_@@ #3
   {
-    \__quark_if_recursion_tail_break:nN {#2} \prop_map_break:
+    \if_meaning:w \q_recursion_tail #2
+      \exp_after:wN \prop_map_break:
+    \fi:
     #1 {#2} {#3}
     \@@_map_function:Nwn #1
   }
@@ -1004,7 +997,7 @@
     \exp_last_unbraced:Nco \@@_map_function:Nwn
       { __prg_map_ \int_use:N \g__prg_map_int :w }
       #1
-      \q_recursion_tail \q_@@ { }
+      \s_@@ \q_recursion_tail \s_@@ { }
     \__prg_break_point:Nn \prop_map_break: { \int_gdecr:N \g__prg_map_int }
   }
 \cs_generate_variant:Nn \prop_map_inline:Nn { c }
@@ -1119,6 +1112,7 @@
 % \begin{macro}{\prop_del:Nn, \prop_del:NV, \prop_del:cn, \prop_del:cV}
 % \begin{macro}{\prop_gdel:Nn, \prop_gdel:NV, \prop_gdel:cn, \prop_gdel:cV}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \prop_del:Nn \prop_remove:Nn
 \cs_new_eq:NN \prop_del:NV \prop_remove:NV
 \cs_new_eq:NN \prop_del:cn \prop_remove:cn
@@ -1127,6 +1121,7 @@
 \cs_new_eq:NN \prop_gdel:NV \prop_gremove:NV
 \cs_new_eq:NN \prop_gdel:cn \prop_gremove:cn
 \cs_new_eq:NN \prop_gdel:cV \prop_gremove:cV
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3seq.dtx b/Master/texmf-dist/source/latex/l3kernel/l3seq.dtx
index f9c8f06e7e3..e917aeda4ea 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3seq.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3seq.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3seq.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3seq.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3seq.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3seq.dtx 4434 2013-01-12 09:33:40Z bruno $
   {L3 Sequences and stacks}
 %</driver|package>
 %<*driver>
@@ -437,8 +437,9 @@
 %   Applies \meta{function} to every \meta{item} stored in the
 %   \meta{sequence}. The \meta{function} will receive one argument for
 %   each iteration. The \meta{items} are returned from left to right.
-%   The function \cs{seq_map_inline:Nn} is in general more efficient
-%   than \cs{seq_map_function:NN}.
+%   The function \cs{seq_map_inline:Nn} is faster than
+%   \cs{seq_map_function:NN} for sequences with more than about~$10$
+%   items.
 %   One mapping may be nested inside another.
 % \end{function}
 %
@@ -882,12 +883,10 @@
 % \UnitTested
 %   Concatenating sequences is easy.
 %    \begin{macrocode}
-\cs_new_protected:Npn \seq_concat:NNN #1#2#3
-  { \tl_set:Nx #1 { \exp_not:o {#2} \exp_not:o {#3} } }
-\cs_new_protected:Npn \seq_gconcat:NNN #1#2#3
-  { \tl_gset:Nx #1 { \exp_not:o {#2} \exp_not:o {#3} } }
-\cs_generate_variant:Nn \seq_concat:NNN  { ccc }
-\cs_generate_variant:Nn \seq_gconcat:NNN { ccc }
+\cs_new_eq:NN \seq_concat:NNN  \tl_concat:NNN
+\cs_new_eq:NN \seq_gconcat:NNN \tl_gconcat:NNN
+\cs_new_eq:NN \seq_concat:ccc  \tl_concat:ccc
+\cs_new_eq:NN \seq_gconcat:ccc \tl_gconcat:ccc
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -895,14 +894,8 @@
 % \begin{macro}[pTF]{\seq_if_exist:N, \seq_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \seq_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \seq_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \seq_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \seq_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \seq_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \seq_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \seq_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \seq_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \seq_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \seq_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1604,8 +1597,10 @@
 %
 % \begin{macro}{\seq_length:N, \seq_length:c}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \seq_length:N \seq_count:N
 \cs_new_eq:NN \seq_length:c \seq_count:c
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % 
@@ -1614,8 +1609,10 @@
 % \begin{macro}{\seq_use:N, \seq_use:c}
 %   A simple short cut for a mapping.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new:Npn \seq_use:N #1 { \seq_map_function:NN #1 \use:n }
 \cs_generate_variant:Nn \seq_use:N { c }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx b/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx
index 3eb3eb8c901..1a9d70f8756 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3skip.dtx
@@ -1,7 +1,7 @@
 % \iffalse meta-comment
 %
 %% File: l3skip.dtx Copyright (C) 2004-2011 Frank Mittelbach, The LaTeX3 Project
-%%                            (C) 2012 The LaTeX3 Project
+%%                            (C) 2012,2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -36,7 +36,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3skip.dtx 4260 2012-11-04 17:20:25Z joseph $
+\GetIdInfo$Id: l3skip.dtx 4444 2013-01-13 20:27:20Z bruno $
   {L3 Dimensions and skips}
 %</driver|package>
 %<*driver>
@@ -228,16 +228,37 @@
 %   \end{center}
 % \end{function}
 %
-% \begin{function}[EXP,pTF]{\dim_compare:n}
+% \begin{function}[updated = 2013-01-13, EXP, pTF]{\dim_compare:n}
 %   \begin{syntax}
-%     \cs{dim_compare_p:n} \{ \meta{dimexpr_1} \meta{relation} \meta{dimexpr_2} \} \\
+%     \cs{dim_compare_p:n} \\
+%     ~~\{ \\
+%     ~~~~\meta{dimexpr_1} \meta{relation_1} \\
+%     ~~~~\ldots{} \\
+%     ~~~~\meta{dimexpr_N} \meta{relation_N} \\
+%     ~~~~\meta{dimexpr_{N+1}} \\
+%     ~~\} \\
 %     \cs{dim_compare:nTF}
-%     ~~\{ \meta{dimexpr_1} \meta{relation} \meta{dimexpr_2} \}
+%     ~~\{ \\
+%     ~~~~\meta{dimexpr_1} \meta{relation_1} \\
+%     ~~~~\ldots{} \\
+%     ~~~~\meta{dimexpr_N} \meta{relation_N} \\
+%     ~~~~\meta{dimexpr_{N+1}} \\
+%     ~~\} \\
 %     ~~\Arg{true code} \Arg{false code}
 %   \end{syntax}
-%   This function first evaluates each of the \meta{dimension expressions}
-%   as described for \cs{dim_eval:n}. The two results are then
-%   compared using the \meta{relation}:
+%   This function evaluates the \meta{dimension expressions} as
+%   described for \cs{dim_eval:n} and compares consecutive result using
+%   the corresponding \meta{relation}, namely it compares
+%   \meta{dimexpr_1} and \meta{dimexpr_2} using the \meta{relation_1},
+%   then \meta{dimexpr_2} and \meta{dimexpr_3} using the
+%   \meta{relation_2}, until finally comparing \meta{dimexpr_N} and
+%   \meta{dimexpr_{N+1}} using the \meta{relation_N}.  The test yields
+%   \texttt{true} if all comparisons are \texttt{true}.  Each
+%   \meta{dimension expression} is evaluated only once, and the
+%   evaluation is lazy, in the sense that if one comparison is
+%   \texttt{false}, then no other \meta{dimension expression} is
+%   evaluated and no other comparison is performed.  The
+%   \meta{relations} can be any of the following:
 %   \begin{center}
 %     \begin{tabular}{ll}
 %       Equal                    & |=| or |==| \\
@@ -331,35 +352,35 @@
 %   \texttt{false}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\dim_do_until:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\dim_do_until:nn}
 %   \begin{syntax}
-%      \cs{dim_do_until:nn} \{ \meta{dimexpr_1} \meta{relation} \meta{dimexpr_2} \} \Arg{code}
+%      \cs{dim_do_until:nn} \Arg{dimension relation} \Arg{code}
 %   \end{syntax}
 %   Places the \meta{code} in the input stream for \TeX{} to process, and
-%   then evaluates the relationship between the two
-%   \meta{dimension expressions} as described for \cs{dim_compare:nTF}.
+%   then evaluates the \meta{dimension relation}
+%   as described for \cs{dim_compare:nTF}.
 %   If the test is \texttt{false} then the \meta{code} will be inserted
 %   into the input stream again and a loop will occur until the
 %   \meta{relation} is \texttt{true}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\dim_do_while:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\dim_do_while:nn}
 %   \begin{syntax}
-%      \cs{dim_do_while:nn} \{ \meta{dimexpr_1} \meta{relation} \meta{dimexpr_2} \} \Arg{code}
+%      \cs{dim_do_while:nn} \Arg{dimension relation} \Arg{code}
 %   \end{syntax}
 %   Places the \meta{code} in the input stream for \TeX{} to process, and
-%   then evaluates the relationship between the two
-%   \meta{dimension expressions} as described for \cs{dim_compare:nTF}.
+%   then evaluates the \meta{dimension relation}
+%   as described for \cs{dim_compare:nTF}.
 %   If the test is \texttt{true} then the \meta{code} will be inserted
 %   into the input stream again and a loop will occur until the
 %   \meta{relation} is \texttt{false}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\dim_until_do:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\dim_until_do:nn}
 %   \begin{syntax}
-%      \cs{dim_until_do:nn} \{ \meta{dimexpr_1} \meta{relation} \meta{dimexpr_2} \} \Arg{code}
+%      \cs{dim_until_do:nn} \Arg{dimension relation} \Arg{code}
 %   \end{syntax}
-%   Evaluates the relationship between the two \meta{dimension expressions}
+%   Evaluates the \meta{dimension relation}
 %   as described for \cs{dim_compare:nTF}, and then places the
 %   \meta{code} in the input stream if the \meta{relation} is
 %   \texttt{false}. After the \meta{code} has been processed by \TeX{} the
@@ -367,11 +388,11 @@
 %   \texttt{true}.
 % \end{function}
 %
-% \begin{function}[rEXP]{\dim_while_do:nn}
+% \begin{function}[updated = 2013-01-13, rEXP]{\dim_while_do:nn}
 %   \begin{syntax}
-%      \cs{dim_while_do:nn} \{ \meta{dimexpr_1} \meta{relation} \meta{dimexpr_2} \} \Arg{code}
+%      \cs{dim_while_do:nn} \Arg{dimension relation} \Arg{code}
 %   \end{syntax}
-%   Evaluates the relationship between the two \meta{dimension expressions}
+%   Evaluates the \meta{dimension relation}
 %   as described for \cs{dim_compare:nTF}, and then places the
 %   \meta{code} in the input stream if the \meta{relation} is
 %   \texttt{true}. After the \meta{code} has been processed by \TeX{} the
@@ -991,14 +1012,8 @@
 % \begin{macro}[pTF]{\dim_if_exist:N, \dim_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \dim_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \dim_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \dim_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \dim_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \dim_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \dim_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \dim_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \dim_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \dim_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \dim_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1134,58 +1149,61 @@
 % \end{macro}
 %
 % \begin{macro}[pTF, EXP]{\dim_compare:n}
-% \begin{macro}[aux, EXP]{\@@_compare_aux:w, \@@_compare_aux:NNw}
+% \begin{macro}[aux, EXP]{\@@_compare:w, \@@_compare:wNN}
 % \begin{macro}[aux, EXP]
 %   {
-%     \@@_compare_=:NNw,
-%     \@@_compare_<:NNw,
-%     \@@_compare_>:NNw,
-%     \@@_compare_==:NNw,
-%     \@@_compare_!=:NNw,
-%     \@@_compare_<=:NNw,
-%     \@@_compare_>=:NNw
+%     \@@_compare_=:w,
+%     \@@_compare_!:w,
+%     \@@_compare_<:w,
+%     \@@_compare_>:w
 %   }
 %   This code is adapted from the \cs{int_compare:nTF} function.  First
-%   evaluate the left-hand side.  Then access the relation symbol by
-%   grabbing until \texttt{pt} (with category other), and pursue
-%   otherwise just as for \cs{int_compare:nTF}.
+%   make sure that there is at least one relation operator, by
+%   evaluating a dimension expression with a trailing
+%   \cs{__prg_compare_error:}.  Just like for integers, the looping
+%   auxiliary \cs{@@_compare:wNN} closes a primitive conditional and
+%   opens a new one.  It is actually easier to grab a dimension operand
+%   than an integer one, because once evaluated, dimensions all end with
+%   \texttt{pt} (with category other).  Thus we do not need specific
+%   auxiliaries for the three \enquote{simple} relations |<|, |=|,
+%   and~|>|.
 %    \begin{macrocode}
 \prg_new_conditional:Npnn \dim_compare:n #1 { p , T , F , TF }
   {
-    \exp_after:wN \@@_compare_aux:w \dim_use:N \@@_eval:w #1
-        \__prg_compare_error: \@@_eval_end:
-      \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
+    \exp_after:wN \@@_compare:w
+    \dim_use:N \@@_eval:w #1 \__prg_compare_error:
   }
-\exp_args:Nno \use:nn
-  { \cs_new:Npn \@@_compare_aux:w #1 }
-  { \tl_to_str:n { pt } }
-  #2 \__prg_compare_error:
+\cs_new:Npn \@@_compare:w #1 \__prg_compare_error:
   {
-    \exp_after:wN \@@_compare_aux:NNw #2 ?? \q_mark
-    #1 pt #2
+    \exp_after:wN \if_false: \tex_romannumeral:D -`0
+      \@@_compare:wNN #1 ? { = \@@_compare_end:w \else: } \q_stop
   }
-\cs_new:Npn \@@_compare_aux:NNw #1#2#3 \q_mark
+\exp_args:Nno \use:nn
+  { \cs_new:Npn \@@_compare:wNN #1 }
+  { \tl_to_str:n {pt} }
+  #2#3
   {
-    \use:c { @@_compare_  #1  \if_meaning:w = #2 =  \fi: :NNw }
-      \__prg_compare_error:Nw #1
+      \if_meaning:w = #3
+        \use:c { @@_compare_#2:w }
+      \fi:
+        #1 pt \exp_stop_f:
+      \prg_return_false:
+      \exp_after:wN \use_none_delimit_by_q_stop:w
+    \fi:
+    \reverse_if:N \if_dim:w #1 pt #2
+      \exp_after:wN \@@_compare:wNN
+      \dim_use:N \@@_eval:w #3
   }
-\cs_new:cpn { @@_compare_=:NNw } #1#2#3 =
-  { \if_dim:w #3 = \@@_eval:w }
-\cs_new:cpn { @@_compare_<:NNw } #1#2#3 <
-  { \if_dim:w #3 < \@@_eval:w }
-\cs_new:cpn { @@_compare_>:NNw } #1#2#3 >
-  { \if_dim:w #3 > \@@_eval:w }
-\cs_new:cpn { @@_compare_==:NNw } #1#2#3 ==
-  { \if_dim:w #3 = \@@_eval:w }
-\cs_new:cpn { @@_compare_!=:NNw } #1#2#3 !=
-  { \reverse_if:N \if_dim:w #3 = \@@_eval:w }
-\cs_new:cpn { @@_compare_<=:NNw } #1#2#3 <=
-  { \reverse_if:N \if_dim:w #3 > \@@_eval:w }
-\cs_new:cpn { @@_compare_>=:NNw } #1#2#3 >=
-  { \reverse_if:N \if_dim:w #3 < \@@_eval:w }
+\cs_new:cpn { @@_compare_ ! :w }
+    #1 \reverse_if:N #2 ! #3 = { #1 #2 = #3 }
+\cs_new:cpn { @@_compare_ = :w }
+    #1 \@@_eval:w = { #1 \@@_eval:w }
+\cs_new:cpn { @@_compare_ < :w }
+    #1 \reverse_if:N #2 < #3 = { #1 #2 > #3 }
+\cs_new:cpn { @@_compare_ > :w }
+    #1 \reverse_if:N #2 > #3 = { #1 #2 < #3 }
+\cs_new:Npn \@@_compare_end:w #1 \prg_return_false: #2 \q_stop
+  { #1 \prg_return_false: \else: \prg_return_true: \fi: }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -1454,14 +1472,8 @@
 % \begin{macro}[pTF]{\skip_if_exist:N, \skip_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \skip_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \skip_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \skip_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \skip_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \skip_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \skip_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \skip_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \skip_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \skip_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \skip_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1705,14 +1717,8 @@
 % \begin{macro}[pTF]{\muskip_if_exist:N, \muskip_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \muskip_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \muskip_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \muskip_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \muskip_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \muskip_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \muskip_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \muskip_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \muskip_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \muskip_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \muskip_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1847,8 +1853,10 @@
 % \begin{macro}[EXP, pTF]{\skip_if_infinite_glue:n}
 %   Reverse of \cs{skip_if_finite:nTF}.
 %    \begin{macrocode}
+%<*deprecated>
 \prg_new_conditional:Npnn \skip_if_infinite_glue:n #1 { p , T , F , TF }
   { \skip_if_finite:nTF {#1} \prg_return_false: \prg_return_true: }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1858,14 +1866,18 @@
 %   Moved here, was in \pkg{l3prg} but load order means we define it here
 %   now.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \prg_case_dim:nnn \dim_case:nnn
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % 
 % \begin{macro}{\dim_eval:w, \dim_eval_end:}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \dim_eval:w    \__dim_eval:w
 \cs_new_eq:NN \dim_eval_end: \__dim_eval_end:
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -1876,6 +1888,7 @@
 % \begin{macro}[aux]{\@@_set_max:NNNn}
 %   Deprecated on 2012-09-09 for removal after 2012-12-31.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_protected_nopar:Npn \dim_set_max:Nn
   { \@@_set_max:NNNn < \dim_set:Nn }
 \cs_new_protected_nopar:Npn \dim_gset_max:Nn
@@ -1890,6 +1903,7 @@
 \cs_generate_variant:Nn \dim_gset_max:Nn { c }
 \cs_generate_variant:Nn \dim_set_min:Nn  { c }
 \cs_generate_variant:Nn \dim_gset_min:Nn { c }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx b/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx
index 0f166541978..dc164dc20c8 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3tl.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3tl.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3tl.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3tl.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3tl.dtx 4415 2013-01-08 12:32:51Z bruno $
   {L3 Token lists}
 %</driver|package>
 %<*driver>
@@ -465,8 +465,8 @@
 % \begin{function}[updated = 2011-08-13, EXP,pTF]
 %   {\tl_if_single:N, \tl_if_single:c}
 %   \begin{syntax}
-%     \cs{tl_if_single_p:N} \Arg{tl~var}
-%     \cs{tl_if_single:NTF} \Arg{tl~var} \Arg{true code} \Arg{false code}
+%     \cs{tl_if_single_p:N} \meta{tl~var}
+%     \cs{tl_if_single:NTF} \meta{tl~var} \Arg{true code} \Arg{false code}
 %   \end{syntax}
 %   Tests if the content of the \meta{tl~var} consists of a single item,
 %   \emph{i.e.}~is a single normal token (neither an explicit space
@@ -680,7 +680,7 @@
 %
 % \begin{function}[added = 2012-05-13, EXP]{\tl_count:N, \tl_count:c}
 %   \begin{syntax}
-%     \cs{tl_count:N} \Arg{tl~var}
+%     \cs{tl_count:N} \meta{tl~var}
 %   \end{syntax}
 %   Counts the number of token groups in the \meta{tl~var}
 %   and leaves this information in the input stream. Unbraced tokens
@@ -714,7 +714,7 @@
 % \begin{function}[updated = 2012-01-08]
 %   {\tl_reverse:N, \tl_reverse:c, \tl_greverse:N, \tl_greverse:c}
 %   \begin{syntax}
-%     \cs{tl_reverse:N} \Arg{tl~var}
+%     \cs{tl_reverse:N} \meta{tl~var}
 %   \end{syntax}
 %   Reverses the order of the \meta{items} stored in \meta{tl~var}, so
 %   that \meta{item_1}\meta{item_2}\meta{item_3} \ldots \meta{item_n}
@@ -1150,14 +1150,8 @@
 % \begin{macro}[pTF]{\tl_if_exist:N, \tl_if_exist:c}
 %   Copies of the \texttt{cs} functions defined in \pkg{l3basics}.
 %    \begin{macrocode}
-\cs_new_eq:NN \tl_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \tl_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \tl_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \tl_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \tl_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \tl_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \tl_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \tl_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \tl_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \tl_if_exist:c \cs_if_exist:c { TF , T , F , p }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -2543,7 +2537,7 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \tl_show:N #1
   {
-    \cs_if_exist:NTF #1
+    \tl_if_exist:NTF #1
       { \cs_show:N #1 }
       {
         \__msg_kernel_error:nnx { kernel } { variable-not-defined }
@@ -2704,7 +2698,9 @@
 %
 % \begin{macro}{\tl_length_tokens:n}
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \tl_length_tokens:n \tl_count_tokens:n
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -2714,11 +2710,13 @@
 %   {\tl_length:N, \tl_length:c, \tl_length:n, \tl_length:V, \tl_length:o}
 %   Renames.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new_eq:NN \tl_length:N \tl_count:N
 \cs_new_eq:NN \tl_length:c \tl_count:c
 \cs_new_eq:NN \tl_length:n \tl_count:n
 \cs_new_eq:NN \tl_length:V \tl_count:V
 \cs_new_eq:NN \tl_length:o \tl_count:o
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -2730,8 +2728,10 @@
 %   a token list is empty if and only if its string representation is
 %   empty.
 %    \begin{macrocode}
+%<*deprecated>
 \prg_new_conditional:Npnn \tl_if_empty:x #1 { p , T , F , TF }
   { \__str_if_eq_x_return:nn { } {#1} }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
@@ -2741,12 +2741,14 @@
 % \begin{macro}[EXP, pTF]{\tl_if_head_N_type:n}
 % \begin{macro}[EXP, pTF]{\tl_if_head_space:n}
 %    \begin{macrocode}
+%<*deprecated>
 \prg_new_eq_conditional:NNn \tl_if_head_group:n \tl_if_head_is_group:n
   { p , T , F , TF }
 \prg_new_eq_conditional:NNn \tl_if_head_N_type:n \tl_if_head_is_N_type:n
   { p , T , F , TF }
 \prg_new_eq_conditional:NNn \tl_if_head_space:n \tl_if_head_is_space:n
   { p , T , F , TF }
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -2756,11 +2758,12 @@
 %   Deprecated 2012-09-01 for removal after 2012-12-31. This is broken as
 %   it will strip braces from a case such as |a{bc}|.
 %    \begin{macrocode}
+%<*deprecated>
 \cs_new:Npn \tl_tail:w #1#2 \q_stop {#2}
+%</deprecated>
 %    \end{macrocode}
 % \end{macro}
 %
-%
 %    \begin{macrocode}
 %</initex|package>
 %    \end{macrocode}
diff --git a/Master/texmf-dist/source/latex/l3kernel/l3token.dtx b/Master/texmf-dist/source/latex/l3kernel/l3token.dtx
index 6e3ef14d414..16e5510475a 100644
--- a/Master/texmf-dist/source/latex/l3kernel/l3token.dtx
+++ b/Master/texmf-dist/source/latex/l3kernel/l3token.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3token.dtx Copyright (C) 2005-2012 The LaTeX3 Project
+%% File: l3token.dtx Copyright (C) 2005-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -35,7 +35,7 @@
 %
 %<*driver|package>
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3token.dtx 4384 2012-12-20 15:47:56Z bruno $
+\GetIdInfo$Id: l3token.dtx 4428 2013-01-10 13:23:29Z bruno $
   {L3 Experimental token manipulation}
 %</driver|package>
 %<*driver>
@@ -1759,7 +1759,7 @@
 %   token has either a space (e.g., |the letter A|), a digit
 %   (e.g., |\count123|) or a double quote (e.g., |\char"A|).
 %
-%   Ten exceptions: on the one hand, \cs{c_undefined:D} is not a
+%   Ten exceptions: on the one hand, \cs{tex_undefined:D} is not a
 %   primitive, but its meaning is |undefined|, only letters;
 %   on the other hand, \tn{space}, \tn{italiccorr},
 %   \tn{hyphen}, \tn{firstmark}, \tn{topmark},
@@ -1781,7 +1781,7 @@
 %
 %   We are now left with a string, which we must analyze. For primitives,
 %   it contains only letters. For non-primitives, it contains either
-%   |"|, or a space, or a digit. Two exceptions remain: \cs{c_undefined:D},
+%   |"|, or a space, or a digit. Two exceptions remain: \cs{tex_undefined:D},
 %   which is not a primitive, and \tn{nullfont}, which is a primitive.
 %
 %   Spaces cannot be grabbed in an undelimited way, so we check them
@@ -1790,7 +1790,7 @@
 %   first character less than |`A| (this is not quite a test for
 %   \enquote{only letters}, but is close enough to work in this context).
 %   If this first character is |:| then we have a primitive, or
-%   \cs{c_undefined:D}, and if it is |"| or a digit, then the token
+%   \cs{tex_undefined:D}, and if it is |"| or a digit, then the token
 %   is not a primitive.
 %
 %    \begin{macrocode}
@@ -2076,30 +2076,26 @@
 % \end{macro}
 %
 % \begin{macro}{\@@_ignore_spaces_execute_branches:}
-% \begin{macro}[aux]{\@@_ignore_spaces_execute_branches_aux:}
-%   This function removes one token at a time with the same mechanism as
-%   \cs{@@_true_remove:w}.  We directly use the primitive meaning test
-%   rather than \cs{token_if_eq_meaning:NNTF} because \cs{l_peek_token}
-%   may be an outer macro (coming from non-\LaTeX3 packages).  We cannot
-%   replace \cs{@@_tmp:w} by \cs{l_peek_token} here because if the
-%   latter is an outer macro, it may not appear in the skipped branch of
-%   a conditional.
+%   This function removes one space token at a time, and calls
+%   \cs{@@_execute_branches:} when encountering the first non-space
+%   token.  We directly use the primitive meaning test rather than
+%   \cs{token_if_eq_meaning:NNTF} because \cs{l_peek_token} may be an
+%   outer macro (coming from non-\LaTeX3 packages).  Spaces are removed
+%   using a side-effect of \texttt{f}-expansion:
+%   |\tex_romannumeral:D -`0| removes one space.
 %    \begin{macrocode}
 \cs_new_protected_nopar:Npn \@@_ignore_spaces_execute_branches:
   {
     \if_meaning:w \l_peek_token \c_space_token
-      \tex_afterassignment:D \@@_ignore_spaces_execute_branches_aux:
-      \exp_after:wN \cs_set_eq:NN
-      \exp_after:wN \@@_tmp:w
+      \exp_after:wN \peek_after:Nw
+      \exp_after:wN \@@_ignore_spaces_execute_branches:
+      \tex_romannumeral:D -`0
     \else:
       \exp_after:wN \@@_execute_branches:
     \fi:
   }
-\cs_new_protected_nopar:Npn \@@_ignore_spaces_execute_branches_aux:
-  { \peek_after:Nw \@@_ignore_spaces_execute_branches: }
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
 %
 % \begin{macro}[aux]{\@@_def:nnnn}
 % \begin{macro}[aux]{\@@_def:nnnnn}
diff --git a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
index b460dc095cb..4e7635b8be3 100644
--- a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
@@ -1,6 +1,6 @@
 % \iffalse meta-comment
 %
-%% File: l3keys2e.dtx (C) Copyright 2009,2011,2012 The LaTeX3 Project
+%% File: l3keys2e.dtx (C) Copyright 2009,2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -37,8 +37,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2012/12/21]
-%<package>\@ifpackagelater{expl3}{2012/12/21}
+\RequirePackage{expl3}[2013/03/12]
+%<package>\@ifpackagelater{expl3}{2013/03/12}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{l3keys2e}{Support package l3kernel too old}
@@ -50,7 +50,7 @@
 %<package>      }%
 %<package>    \endinput
 %<package>  }
-\GetIdInfo$Id: l3keys2e.dtx 4390 2012-12-21 06:59:20Z joseph $
+\GetIdInfo$Id: l3keys2e.dtx 4467 2013-03-12 08:29:05Z joseph $
   {LaTeX2e option processing using LaTeX3 keys}
 %</driver|package>
 %<*driver>
@@ -153,11 +153,11 @@
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
 %    \end{macrocode}
 %
-% \begin{macro}{\@@_latexe_options_clist}
+% \begin{macro}{\l_@@_latexe_options_clist}
 %   A single list is used for all options, into which they are collected
 %   before processing.
 %    \begin{macrocode}
-\clist_new:N \@@_latexe_options_clist
+\clist_new:N \l_@@_latexe_options_clist
 %    \end{macrocode}
 % \end{macro}
 %
@@ -171,7 +171,7 @@
 %
 % \begin{macro}{\@@_latexe_options:n}
 %   The main function calls functions to collect up the global and local
-%   options into \cs{@@_latexe_options_clist} before calling the
+%   options into \cs{l_@@_latexe_options_clist} before calling the
 %   underlying functions to actually do the processing. So that a suitable
 %   message is produced if the option is unknown, the special
 %   \texttt{unknown} key is set if it does not already exist for the
@@ -179,7 +179,7 @@
 %    \begin{macrocode}
 \cs_new_protected:Npn \@@_latexe_options:n #1
   {
-    \clist_clear:N \@@_latexe_options_clist
+    \clist_clear:N \l_@@_latexe_options_clist
     \@@_latexe_options_global:n {#1}
     \@@_latexe_options_local:
     \keys_if_exist:nnF {#1} { unknown }
@@ -193,7 +193,7 @@
               }
           }
       }
-    \keys_set:nV {#1} \@@_latexe_options_clist
+    \keys_set:nV {#1} \l_@@_latexe_options_clist
     \AtEndOfPackage { \cs_set_eq:NN \@unprocessedoptions \scan_stop: }
   }
 %    \end{macrocode}
@@ -231,12 +231,12 @@
 \cs_new_protected:Npn \@@_latexe_options_class:n #1
   {
     \keys_if_exist:nnTF {#1} { unknown }
-      { \clist_put_right:No \@@_latexe_options_clist \@classoptionslist }
+      { \clist_put_right:No \l_@@_latexe_options_clist \@classoptionslist }
       {
         \clist_map_inline:Nn \@classoptionslist
           {
             \keys_if_exist:nnTF {#1} { \@@_latexe_remove_equals:n {##1} }
-              { \clist_put_right:Nn \@@_latexe_options_clist {##1} }
+              { \clist_put_right:Nn \l_@@_latexe_options_clist {##1} }
               { \clist_put_right:Nn \@unusedoptionlist {##1} }
           }
       }
@@ -256,7 +256,7 @@
       {
         \keys_if_exist:nnT {#1} { \@@_latexe_remove_equals:n {##1} }
           {
-            \clist_put_right:Nn \@@_latexe_options_clist {##1}
+            \clist_put_right:Nn \l_@@_latexe_options_clist {##1}
             \clist_remove_all:Nn \@unusedoptionlist {##1}
           }
       }
@@ -275,7 +275,7 @@
       {
         \cs_if_exist:cT { opt@ \@currname . \@currext }
           {
-            \exp_args:NNc \clist_put_right:NV \@@_latexe_options_clist
+            \exp_args:NNc \clist_put_right:NV \l_@@_latexe_options_clist
               { opt@ \@currname . \@currext }
           }
       }
diff --git a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
index 67b80d5358a..64a7cb504d9 100644
--- a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
@@ -4,7 +4,7 @@
 %%                      David Carlisle
 %%                  (C) Copyright 2004-2008 Frank Mittelbach,
 %%                      The LaTeX3 Project
-%%                  (C) Copyright 2009-2012 The LaTeX3 Project
+%%                  (C) Copyright 2009-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -41,8 +41,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2012/12/21]
-%<package>\@ifpackagelater{expl3}{2012/12/21}
+\RequirePackage{expl3}[2013/03/12]
+%<package>\@ifpackagelater{expl3}{2013/03/12}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{xparse}{Support package l3kernel too old}
@@ -54,7 +54,7 @@
 %<package>      }%
 %<package>    \endinput
 %<package>  }
-\GetIdInfo$Id: xparse.dtx 4390 2012-12-21 06:59:20Z joseph $
+\GetIdInfo$Id: xparse.dtx 4467 2013-03-12 08:29:05Z joseph $
   {L3 Experimental document command parser}
 %</driver|package>
 %<*driver>
@@ -200,24 +200,19 @@
 % `|s o o m O{default}|', the input `|*[Foo]{Bar}|' would be parsed as:
 % \begin{itemize}[nolistsep]
 %   \item |#1| = |\BooleanTrue|
-%   \item |#2| = |{Foo}|
+%   \item |#2| = |Foo|
 %   \item |#3| = |-NoValue-|
-%   \item |#4| = |{Bar}|
-%   \item |#5| = |{default}|
+%   \item |#4| = |Bar|
+%   \item |#5| = |default|
 % \end{itemize}
 % whereas `|[One][Two]{}[Three]|' would be parsed as:
 % \begin{itemize}[nolistsep]
 %   \item |#1| = |\BooleanFalse|
-%   \item |#2| = |{One}|
-%   \item |#3| = |{Two}|
-%   \item |#4| = |{}|
-%   \item |#5| = |{Three}|
+%   \item |#2| = |One|
+%   \item |#3| = |Two|
+%   \item |#4| = ||
+%   \item |#5| = |Three|
 % \end{itemize}
-% Note that after parsing the input there will be always exactly the
-% same number of \meta{balanced text} arguments as the number of letters
-% in the argument specifier. The \cs{BooleanTrue} and \cs{BooleanFalse}
-% tokens are passed without braces; all other arguments are passed as
-% brace groups.
 % 
 % Delimited argument types (\texttt{d}, \texttt{o} and \texttt{r}) are
 % defined such that they require matched pairs of delimiters when collecting
@@ -230,6 +225,20 @@
 % Also note that |{| and |}| cannot be used as delimiters as they are used
 % by \TeX{} as grouping tokens. Arguments to be grabbed inside these tokens
 % must be created as either \texttt{m}- or \texttt{g}-type arguments.
+% 
+% Within delimited arguments, non-balanced or otherwise awkward tokens may
+% be included by protecting the entire argument with a brace pair
+% \begin{verbatim}
+%   \DeclareDocumentCommand{\foo}{o}{#1}
+%   \foo[{[}]         % Allowed as the "[" is 'hidden'
+% \end{verbatim}
+% These braces will be stripped if they surround the \emph{entire} content
+% of the optional argument
+% \begin{verbatim}
+%   \DeclareDocumentCommand{\foo}{o}{#1}
+%   \foo[{abc}]         % => "abc"
+%   \foo[ {abc}]         % => " {abc}"
+% \end{verbatim}
 %
 % Two more tokens have a special meaning when creating an argument
 % specifier. First, \texttt{+} is used to make an argument long (to
@@ -1868,6 +1877,13 @@
         #4 \l_@@_args_tl
       }
   }
+%    \end{macrocode}
+%   Inside the \enquote{standard} grabber, there is a test to see if the
+%   grabbed argument is entirely enclosed by braces. There are a couple of
+%   extra factors to allow for: the argument might be entirely empty, and
+%   spaces at the start and end of the input must be retained around a brace
+%   group.
+%    \begin{macrocode}
 \cs_new_protected:Npn \@@_grab_D_aux:NNnN #1#2#3#4
   {
     \cs_set_protected_nopar:Npn \@@_grab_arg:w
@@ -1877,7 +1893,15 @@
             \tl_if_in:nnTF {####1} {#1}
               { \@@_grab_D_nested:NNnnN #1 #2 {####1} {#3} #4 }
               {
-                \@@_add_arg:o { \use_none:n ####1 }
+                \tl_if_blank:oTF { \use_none:n ####1 }
+                  { \@@_add_arg:o { \use_none:n ####1 } }
+                  {
+                    \str_if_eq_x:nnTF
+                      { \exp_not:o { \use_none:n ####1 } }
+                      { { \exp_not:o { \use_ii:nnn ####1 \q_nil } } }
+                      { \@@_add_arg:o { \use_ii:nn ####1 } }
+                      { \@@_add_arg:o { \use_none:n ####1 } }
+                  }
                 #3 \l_@@_args_tl
               }
           }
@@ -2683,14 +2707,23 @@
 %   delimiter. In that case, we are done, and put the argument (from which we
 %   remove a spurious pair of delimiters coming from how we started the loop).
 %   Otherwise, we go back to looping with
-%   \cs{@@_expandable_grab_D:NNNwNnnn}.
+%   \cs{@@_expandable_grab_D:NNNwNnnn}. The code to deal with brace stripping
+%   is much the same as for the non-expandable case.
 %    \begin{macrocode}
 \cs_new:Npn \@@_expandable_grab_D:nnNNNwN #1#2#3#4#5#6 \q_@@ #7
   {
     \exp_args:No \tl_if_empty:oTF
       { #3 { \use_none:nnn } #2 \q_@@ #5 #4 \q_@@ #5 }
       {
-        \@@_put_arg_expandable:ow { \use_none:nn #1#2 }
+        \tl_if_blank:oTF { \use_none:nn #1#2 }
+          { \@@_put_arg_expandable:ow { } }
+          {
+            \str_if_eq_x:nnTF
+              { \exp_not:o { \use_none:nn #1#2 } }
+              { { \exp_not:o { \use_iii:nnnn #1#2 \q_nil } } }
+              { \@@_put_arg_expandable:ow { \use_iii:nnn #1#2 } }
+              { \@@_put_arg_expandable:ow { \use_none:nn #1#2 } }
+          }
           #6 \q_@@ #7
       }
       {
@@ -2709,7 +2742,7 @@
 % \begin{macro}[EXP]{\@@_expandable_grab_D_alt:w}
 % \begin{macro}[EXP]{\@@_expandable_grab_D_alt:NNnwNn}
 % \begin{macro}[EXP]{\@@_expandable_grab_D_alt:Nw}
-%   When the delimiters are identical, nesting is not possble and a simplified
+%   When the delimiters are identical, nesting is not possible and a simplified
 %   approach is used. The test concept here is the same as for the case where
 %   the delimiters are different.
 %    \begin{macrocode}
@@ -2728,7 +2761,18 @@
       { #4 {#3} \q_@@ #5 {#6} }
   }
 \cs_new:Npn \@@_expandable_grab_D_alt:Nwn #1#2 \q_@@ #3
-  { \@@_put_arg_expandable:ow { \use_none:n #3 } #2 \q_@@ #1 }
+  {
+    \tl_if_blank:oTF { \use_none:nn #1#2 }
+      { \@@_put_arg_expandable:ow { } }
+      {
+        \str_if_eq_x:nnTF
+          { \exp_not:o { \use_none:n #3 } }
+          { { \exp_not:o { \use_ii:nnn #3 \q_nil } } }
+          { \@@_put_arg_expandable:ow { \use_ii:nn #3 } }
+          { \@@_put_arg_expandable:ow { \use_none:n #3 } }
+      }
+      #2 \q_@@ #1
+  }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -3405,19 +3449,29 @@
 % \end{macro}
 %
 % \subsection{Package options}
-%
-% A faked key--value option to keep the log clean. Not yet perfect, but
-% better than nothing.
+% 
+% \begin{variable}{\l_@@_options_clist}
+% \begin{variable}{\l_@@_log_bool}
+%   Key--value option to log information: done by hand to keep dependencies
+%   down.
 %    \begin{macrocode}
-\DeclareOption { log-declarations = true } { }
-\DeclareOption { log-declarations = false }
+\clist_new:N \l_@@_options_clist
+\DeclareOption* { \clist_put_right:NV \l_@@_options_clist \CurrentOption }
+\ProcessOptions \relax
+\keys_define:nn { xparse }
+  {
+    log-declarations .bool_set:N = \l_@@_log_bool ,
+    log-declarations .initial:n  = true
+  }
+\keys_set:nV { xparse } \l_@@_options_clist
+\bool_if:NF \l_@@_log_bool
   {
     \msg_redirect_module:nnn { LaTeX / xparse } { info }    { none }
     \msg_redirect_module:nnn { LaTeX / xparse } { warning } { none }
   }
-\DeclareOption { log-declarations } { }
-\ProcessOptions \scan_stop:
 %    \end{macrocode}
+% \end{variable}
+% \end{variable}
 %
 %    \begin{macrocode}
 %</package>
diff --git a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
index 9f632ae9109..f8467ce2a14 100644
--- a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
@@ -4,7 +4,7 @@
 %%                         David Carlisle
 %%                     (C) Copyright 2004-2010 Frank Mittelbach,
 %%                         The LaTeX3 Project
-%%                     (C) Copyright 2011,2012 The LaTeX3 Project
+%%                     (C) Copyright 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -41,8 +41,8 @@
 %<*driver|package>
 % The version of expl3 required is tested as early as possible, as
 % some really old versions do not define \ProvidesExplPackage.
-\RequirePackage{expl3}[2012/12/21]
-%<package>\@ifpackagelater{expl3}{2012/12/21}
+\RequirePackage{expl3}[2013/03/12]
+%<package>\@ifpackagelater{expl3}{2013/03/12}
 %<package>  {}
 %<package>  {%
 %<package>    \PackageError{xtemplate}{Support package l3kernel too old}
@@ -54,7 +54,7 @@
 %<package>      }%
 %<package>    \endinput
 %<package>  }
-\GetIdInfo$Id: xtemplate.dtx 4390 2012-12-21 06:59:20Z joseph $
+\GetIdInfo$Id: xtemplate.dtx 4467 2013-03-12 08:29:05Z joseph $
   {L3 Experimental prototype document functions}
 %</driver|package>
 %<*driver>
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3dt/l3dt.sty b/Master/texmf-dist/tex/latex/l3experimental/l3dt/l3dt.sty
index 4cb2ad8617b..fb5cc34221f 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3dt/l3dt.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3dt/l3dt.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File l3dt.dtx Copyright (C) 2011,2012 The LaTeX3 Project
+%% File l3dt.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -47,7 +47,7 @@
 %% -----------------------------------------------------------------------
 %%
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3dt.dtx 4190 2012-09-03 00:23:31Z bruno $
+\GetIdInfo$Id: l3dt.dtx 4420 2013-01-08 20:00:04Z joseph $
   {L3 Experimental data tables}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -417,7 +417,7 @@
   }
 \cs_new:Npn \__dt_if_in_row:nwn #1 \q__dt #2 \q__dt #3
   {
-    \str_if_eq:xxTF {#1} {#2}
+    \str_if_eq_x:nnTF {#1} {#2}
       { \__dt_if_in_row:N }
       { \__dt_if_in_row:nwn {#1} }
   }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3flag.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3flag.sty
index 63970cdd45d..a7249a188cb 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3flag.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3flag.sty
@@ -63,7 +63,7 @@
     \else:
       \exp_after:wN \use_none_delimit_by_q_stop:w
     \fi:
-    \cs_set_eq:cN { __flag_#2_#1: } \c_undefined:D
+    \cs_set_eq:cN { __flag_#2_#1: } \tex_undefined:D
     \exp_after:wN \__flag_clear:ww
     \int_use:N \__int_eval:w \c_one + #1 ;
     #2 \q_stop
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex-trace.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex-trace.sty
index ccb695c0f0e..91a6eab725f 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex-trace.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex-trace.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3regex.dtx Copyright (C) 2011-2012 The LaTeX3 Project
+%% File: l3regex.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,11 +46,11 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3regex.dtx 4341 2012-11-27 08:39:42Z bruno $
+\GetIdInfo$Id: l3regex.dtx 4455 2013-01-22 20:38:19Z bruno $
   {L3 Experimental regular expressions}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
-\RequirePackage{l3tl-build, l3tl-analysis, l3flag, l3str}
+\RequirePackage{l3tl-build, l3tl-analysis, l3flag, l3str, l3str-convert}
 \cs_generate_variant:Nn \tl_to_str:n { V }
 \cs_new:Npn \__regex_tmp:w { }
 \tl_new:N   \l__regex_internal_a_tl
@@ -345,7 +345,7 @@
         {
           \__msg_kernel_error:nnx { regex } { x-overflow } {#1}
           \tl_set:Nx \l__regex_internal_b_tl
-            { \if_false: } \fi: \__regex_escape_loop:N
+            { \if_false: } \fi:
         }
         {
           \char_set_lccode:nn { \c_zero } {#1}
@@ -354,7 +354,6 @@
               \tl_set:Nx \l__regex_internal_b_tl
                 { \if_false: } \fi:
                 \__regex_escape_raw:N ^^@
-                \__regex_escape_loop:N
             }
         }
     }
@@ -373,7 +372,7 @@
   }
 \cs_new:Npn \__regex_escape_x_test_two:N #1
   {
-    \if_charcode:w \c_lbrace_str #1
+    \if_charcode:w \c_left_brace_str #1
       \exp_after:wN \__regex_escape_x_loop:N
     \else:
       \__str_hexadecimal_use:NTF #1
@@ -399,7 +398,7 @@
           { \__regex_escape_x_loop:N }
           {
             ;
-            \exp_after:wN \token_if_eq_charcode:NNTF \c_rbrace_str #1
+            \exp_after:wN \token_if_eq_charcode:NNTF \c_right_brace_str #1
               { \__regex_escape_loop:N }
               {
                 \if_false: { \fi: }
@@ -698,17 +697,17 @@
   { \__regex_compile_quantifier_lazyness:nnNN { 0 } { -1 } }
 \cs_new_protected_nopar:cpn { __regex_compile_quantifier_+:w }
   { \__regex_compile_quantifier_lazyness:nnNN { 1 } { -1 } }
-\cs_new_protected:cpn { __regex_compile_quantifier_ \c_lbrace_str :w }
+\cs_new_protected:cpn { __regex_compile_quantifier_ \c_left_brace_str :w }
   {
     \__regex_get_digits:NTFw \l__regex_internal_a_int
       { \__regex_compile_quantifier_braced_auxi:w }
-      { \__regex_compile_quantifier_abort:xNN { \c_lbrace_str } }
+      { \__regex_compile_quantifier_abort:xNN { \c_left_brace_str } }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxi:w #1#2
   {
     \str_case_x:nnn { #1 #2 }
       {
-        { \__regex_compile_special:N \c_rbrace_str }
+        { \__regex_compile_special:N \c_right_brace_str }
           {
             \exp_args:No \__regex_compile_quantifier_lazyness:nnNN
               { \int_use:N \l__regex_internal_a_int } { 0 }
@@ -722,28 +721,28 @@
       }
       {
         \__regex_compile_quantifier_abort:xNN
-          { \c_lbrace_str \int_use:N \l__regex_internal_a_int }
+          { \c_left_brace_str \int_use:N \l__regex_internal_a_int }
         #1 #2
       }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxii:w #1#2
   {
     \str_if_eq_x:nnTF
-      { #1 #2 } { \__regex_compile_special:N \c_rbrace_str }
+      { #1 #2 } { \__regex_compile_special:N \c_right_brace_str }
       {
         \exp_args:No \__regex_compile_quantifier_lazyness:nnNN
           { \int_use:N \l__regex_internal_a_int } { -1 }
       }
       {
         \__regex_compile_quantifier_abort:xNN
-          { \c_lbrace_str \int_use:N \l__regex_internal_a_int , }
+          { \c_left_brace_str \int_use:N \l__regex_internal_a_int , }
         #1 #2
       }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxiii:w #1#2
   {
     \str_if_eq_x:nnTF
-      { #1 #2 } { \__regex_compile_special:N \c_rbrace_str }
+      { #1 #2 } { \__regex_compile_special:N \c_right_brace_str }
       {
         \if_int_compare:w \l__regex_internal_a_int > \l__regex_internal_b_int
           \__msg_kernel_error:nnxx { regex } { backwards-quantifier }
@@ -760,7 +759,7 @@
       {
         \__regex_compile_quantifier_abort:xNN
           {
-            \c_lbrace_str
+            \c_left_brace_str
             \int_use:N \l__regex_internal_a_int ,
             \int_use:N \l__regex_internal_b_int
           }
@@ -1197,14 +1196,14 @@
         { \c__regex_all_catcodes_int - \l__regex_catcodes_int }
     \fi:
   }
-\cs_new_protected_nopar:cpn { __regex_compile_c_ \c_lbrace_str :w }
+\cs_new_protected_nopar:cpn { __regex_compile_c_ \c_left_brace_str :w }
   {
     \__regex_compile:w
       \__regex_disable_submatches:
       \l__regex_mode_int
         = - \if_case:w \l__regex_mode_int \c_two \else: \c_six \fi:
   }
-\cs_new_protected:cpn { __regex_compile_ \c_rbrace_str : }
+\cs_new_protected:cpn { __regex_compile_ \c_right_brace_str : }
   {
     \__regex_if_in_cs:TF
       {
@@ -1212,14 +1211,14 @@
         \__regex_compile_one:x
           { \__regex_item_cs:n { \exp_not:o \l__regex_internal_regex } }
       }
-      { \exp_after:wN \__regex_compile_raw:N \c_rbrace_str }
+      { \exp_after:wN \__regex_compile_raw:N \c_right_brace_str }
   }
 \cs_new_protected:cpn { __regex_compile_/u: } #1#2
   {
     \__regex_if_in_class_or_catcode:TF
       { \__regex_compile_raw_error:N u #1 #2 }
       {
-        \str_if_eq_x:nnTF {#1#2} { \__regex_compile_special:N \c_lbrace_str }
+        \str_if_eq_x:nnTF {#1#2} { \__regex_compile_special:N \c_left_brace_str }
           {
             \tl_set:Nx \l__regex_internal_a_tl { \if_false: } \fi:
             \__regex_compile_u_loop:NN
@@ -1237,7 +1236,7 @@
       {
         \token_if_eq_meaning:NNTF #1 \__regex_compile_special:N
           {
-            \exp_after:wN \token_if_eq_charcode:NNTF \c_rbrace_str #2
+            \exp_after:wN \token_if_eq_charcode:NNTF \c_right_brace_str #2
               { \if_false: { \fi: } \__regex_compile_u_end: }
               { #2 \__regex_compile_u_loop:NN }
           }
@@ -2091,7 +2090,7 @@
       \tl_clear:N \l__regex_balance_tl
       \__regex_escape_use:nnnn
         {
-          \if_charcode:w \c_rbrace_str ##1
+          \if_charcode:w \c_right_brace_str ##1
             \__regex_replacement_rbrace:N \else: \__tl_build_one:n \fi: ##1
         }
         { \__regex_replacement_escaped:N ##1 }
@@ -2147,7 +2146,7 @@
   }
 \cs_new_protected:Npn \__regex_replacement_g:w #1#2
   {
-    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_lbrace_str }
+    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_left_brace_str }
       {
         \int_zero:N \l__regex_internal_a_int
         \__regex_replacement_g_digits:NN
@@ -2189,7 +2188,7 @@
       }
       { \__regex_replacement_error:NNN c #1#2 }
   }
-\cs_new_protected_nopar:cpn { __regex_replacement_c_ \c_lbrace_str :w }
+\cs_new_protected_nopar:cpn { __regex_replacement_c_ \c_left_brace_str :w }
   {
     \if_case:w \l__regex_replacement_csnames_int
       \__tl_build_one:n
@@ -2201,7 +2200,7 @@
   }
 \cs_new_protected:Npn \__regex_replacement_u:w #1#2
   {
-    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_lbrace_str }
+    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_left_brace_str }
       {
         \if_case:w \l__regex_replacement_csnames_int
           \__tl_build_one:n { \exp_not:n { \exp_after:wN \exp_not:V \cs:w } }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex.sty
index 5273399d7be..89f631f7e0b 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3regex.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3regex.dtx Copyright (C) 2011-2012 The LaTeX3 Project
+%% File: l3regex.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,11 +46,11 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3regex.dtx 4341 2012-11-27 08:39:42Z bruno $
+\GetIdInfo$Id: l3regex.dtx 4455 2013-01-22 20:38:19Z bruno $
   {L3 Experimental regular expressions}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
-\RequirePackage{l3tl-build, l3tl-analysis, l3flag, l3str}
+\RequirePackage{l3tl-build, l3tl-analysis, l3flag, l3str, l3str-convert}
 \cs_generate_variant:Nn \tl_to_str:n { V }
 \cs_new:Npn \__regex_tmp:w { }
 \tl_new:N   \l__regex_internal_a_tl
@@ -343,7 +343,7 @@
         {
           \__msg_kernel_error:nnx { regex } { x-overflow } {#1}
           \tl_set:Nx \l__regex_internal_b_tl
-            { \if_false: } \fi: \__regex_escape_loop:N
+            { \if_false: } \fi:
         }
         {
           \char_set_lccode:nn { \c_zero } {#1}
@@ -352,7 +352,6 @@
               \tl_set:Nx \l__regex_internal_b_tl
                 { \if_false: } \fi:
                 \__regex_escape_raw:N ^^@
-                \__regex_escape_loop:N
             }
         }
     }
@@ -371,7 +370,7 @@
   }
 \cs_new:Npn \__regex_escape_x_test_two:N #1
   {
-    \if_charcode:w \c_lbrace_str #1
+    \if_charcode:w \c_left_brace_str #1
       \exp_after:wN \__regex_escape_x_loop:N
     \else:
       \__str_hexadecimal_use:NTF #1
@@ -397,7 +396,7 @@
           { \__regex_escape_x_loop:N }
           {
             ;
-            \exp_after:wN \token_if_eq_charcode:NNTF \c_rbrace_str #1
+            \exp_after:wN \token_if_eq_charcode:NNTF \c_right_brace_str #1
               { \__regex_escape_loop:N }
               {
                 \if_false: { \fi: }
@@ -696,17 +695,17 @@
   { \__regex_compile_quantifier_lazyness:nnNN { 0 } { -1 } }
 \cs_new_protected_nopar:cpn { __regex_compile_quantifier_+:w }
   { \__regex_compile_quantifier_lazyness:nnNN { 1 } { -1 } }
-\cs_new_protected:cpn { __regex_compile_quantifier_ \c_lbrace_str :w }
+\cs_new_protected:cpn { __regex_compile_quantifier_ \c_left_brace_str :w }
   {
     \__regex_get_digits:NTFw \l__regex_internal_a_int
       { \__regex_compile_quantifier_braced_auxi:w }
-      { \__regex_compile_quantifier_abort:xNN { \c_lbrace_str } }
+      { \__regex_compile_quantifier_abort:xNN { \c_left_brace_str } }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxi:w #1#2
   {
     \str_case_x:nnn { #1 #2 }
       {
-        { \__regex_compile_special:N \c_rbrace_str }
+        { \__regex_compile_special:N \c_right_brace_str }
           {
             \exp_args:No \__regex_compile_quantifier_lazyness:nnNN
               { \int_use:N \l__regex_internal_a_int } { 0 }
@@ -720,28 +719,28 @@
       }
       {
         \__regex_compile_quantifier_abort:xNN
-          { \c_lbrace_str \int_use:N \l__regex_internal_a_int }
+          { \c_left_brace_str \int_use:N \l__regex_internal_a_int }
         #1 #2
       }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxii:w #1#2
   {
     \str_if_eq_x:nnTF
-      { #1 #2 } { \__regex_compile_special:N \c_rbrace_str }
+      { #1 #2 } { \__regex_compile_special:N \c_right_brace_str }
       {
         \exp_args:No \__regex_compile_quantifier_lazyness:nnNN
           { \int_use:N \l__regex_internal_a_int } { -1 }
       }
       {
         \__regex_compile_quantifier_abort:xNN
-          { \c_lbrace_str \int_use:N \l__regex_internal_a_int , }
+          { \c_left_brace_str \int_use:N \l__regex_internal_a_int , }
         #1 #2
       }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxiii:w #1#2
   {
     \str_if_eq_x:nnTF
-      { #1 #2 } { \__regex_compile_special:N \c_rbrace_str }
+      { #1 #2 } { \__regex_compile_special:N \c_right_brace_str }
       {
         \if_int_compare:w \l__regex_internal_a_int > \l__regex_internal_b_int
           \__msg_kernel_error:nnxx { regex } { backwards-quantifier }
@@ -758,7 +757,7 @@
       {
         \__regex_compile_quantifier_abort:xNN
           {
-            \c_lbrace_str
+            \c_left_brace_str
             \int_use:N \l__regex_internal_a_int ,
             \int_use:N \l__regex_internal_b_int
           }
@@ -1195,14 +1194,14 @@
         { \c__regex_all_catcodes_int - \l__regex_catcodes_int }
     \fi:
   }
-\cs_new_protected_nopar:cpn { __regex_compile_c_ \c_lbrace_str :w }
+\cs_new_protected_nopar:cpn { __regex_compile_c_ \c_left_brace_str :w }
   {
     \__regex_compile:w
       \__regex_disable_submatches:
       \l__regex_mode_int
         = - \if_case:w \l__regex_mode_int \c_two \else: \c_six \fi:
   }
-\cs_new_protected:cpn { __regex_compile_ \c_rbrace_str : }
+\cs_new_protected:cpn { __regex_compile_ \c_right_brace_str : }
   {
     \__regex_if_in_cs:TF
       {
@@ -1210,14 +1209,14 @@
         \__regex_compile_one:x
           { \__regex_item_cs:n { \exp_not:o \l__regex_internal_regex } }
       }
-      { \exp_after:wN \__regex_compile_raw:N \c_rbrace_str }
+      { \exp_after:wN \__regex_compile_raw:N \c_right_brace_str }
   }
 \cs_new_protected:cpn { __regex_compile_/u: } #1#2
   {
     \__regex_if_in_class_or_catcode:TF
       { \__regex_compile_raw_error:N u #1 #2 }
       {
-        \str_if_eq_x:nnTF {#1#2} { \__regex_compile_special:N \c_lbrace_str }
+        \str_if_eq_x:nnTF {#1#2} { \__regex_compile_special:N \c_left_brace_str }
           {
             \tl_set:Nx \l__regex_internal_a_tl { \if_false: } \fi:
             \__regex_compile_u_loop:NN
@@ -1235,7 +1234,7 @@
       {
         \token_if_eq_meaning:NNTF #1 \__regex_compile_special:N
           {
-            \exp_after:wN \token_if_eq_charcode:NNTF \c_rbrace_str #2
+            \exp_after:wN \token_if_eq_charcode:NNTF \c_right_brace_str #2
               { \if_false: { \fi: } \__regex_compile_u_end: }
               { #2 \__regex_compile_u_loop:NN }
           }
@@ -2065,7 +2064,7 @@
       \tl_clear:N \l__regex_balance_tl
       \__regex_escape_use:nnnn
         {
-          \if_charcode:w \c_rbrace_str ##1
+          \if_charcode:w \c_right_brace_str ##1
             \__regex_replacement_rbrace:N \else: \__tl_build_one:n \fi: ##1
         }
         { \__regex_replacement_escaped:N ##1 }
@@ -2120,7 +2119,7 @@
   }
 \cs_new_protected:Npn \__regex_replacement_g:w #1#2
   {
-    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_lbrace_str }
+    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_left_brace_str }
       {
         \int_zero:N \l__regex_internal_a_int
         \__regex_replacement_g_digits:NN
@@ -2162,7 +2161,7 @@
       }
       { \__regex_replacement_error:NNN c #1#2 }
   }
-\cs_new_protected_nopar:cpn { __regex_replacement_c_ \c_lbrace_str :w }
+\cs_new_protected_nopar:cpn { __regex_replacement_c_ \c_left_brace_str :w }
   {
     \if_case:w \l__regex_replacement_csnames_int
       \__tl_build_one:n
@@ -2174,7 +2173,7 @@
   }
 \cs_new_protected:Npn \__regex_replacement_u:w #1#2
   {
-    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_lbrace_str }
+    \str_if_eq_x:nnTF { #1#2 } { \__tl_build_one:n \c_left_brace_str }
       {
         \if_case:w \l__regex_replacement_csnames_int
           \__tl_build_one:n { \exp_not:n { \exp_after:wN \exp_not:V \cs:w } }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-convert.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-convert.sty
new file mode 100644
index 00000000000..5291a394382
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-convert.sty
@@ -0,0 +1,632 @@
+%%
+%% This is file `l3str-convert.sty',
+%% generated with the docstrip utility.
+%%
+%% The original source files were:
+%%
+%% l3str-convert.dtx  (with options: `package')
+%% 
+%% EXPERIMENTAL CODE
+%% 
+%% Do not distribute this file without also distributing the
+%% source files specified above.
+%% 
+%% Do not distribute a modified version of this file.
+%% 
+%% File: l3str-convert.dtx Copyright (C) 2013 The LaTeX3 Project
+%%
+%% It may be distributed and/or modified under the conditions of the
+%% LaTeX Project Public License (LPPL), either version 1.3c of this
+%% license or (at your option) any later version.  The latest version
+%% of this license is in the file
+%%
+%%    http://www.latex-project.org/lppl.txt
+%%
+%% This file is part of the "l3experimental bundle" (The Work in LPPL)
+%% and all files in that bundle must be distributed together.
+%%
+%% The released version of this bundle is available from CTAN.
+%%
+%% -----------------------------------------------------------------------
+%%
+%% The development version of the bundle can be found at
+%%
+%%    http://www.latex-project.org/svnroot/experimental/trunk/
+%%
+%% for those people who are interested.
+%%
+%%%%%%%%%%%
+%% NOTE: %%
+%%%%%%%%%%%
+%%
+%%   Snapshots taken from the repository represent work in progress and may
+%%   not work or may contain conflicting material!  We therefore ask
+%%   people _not_ to put them into distributions, archives, etc. without
+%%   prior consultation with the LaTeX3 Project.
+%%
+%% -----------------------------------------------------------------------
+\RequirePackage{expl3}
+\GetIdInfo$Id: l3str-convert.dtx 4339 2013-01-08 10:22:00Z bruno $
+  {L3 Experimental string encoding conversions}
+\ProvidesExplPackage
+  {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
+\RequirePackage{l3str,l3tl-analysis,l3tl-build,l3flag}
+\cs_if_exist:NF \use_ii_i:nn
+  { \cs_new:Npn \use_ii_i:nn #1#2 { #2 #1 } }
+\int_const:Nn \c_max_char_int
+  { \pdftex_if_engine:TF { "FF } { "10FFFF } }
+\cs_new_protected_nopar:Npn \__str_tmp:w { }
+\tl_new:N \l__str_internal_tl
+\int_new:N \l__str_internal_int
+\tl_new:N \g__str_result_tl
+\int_const:Nn \c__str_replacement_char_int { "FFFD }
+\int_const:Nn \c_forty_eight  { 48 }
+\int_const:Nn \c_fifty_eight  { 58 }
+\int_const:Nn \c_sixty_five   { 65 }
+\int_const:Nn \c_ninety_one   { 91 }
+\int_const:Nn \c_ninety_seven { 97 }
+\int_const:Nn \c_one_hundred_twenty_three { 123 }
+\int_const:Nn \c_one_hundred_twenty_seven { 127 }
+\prop_new:N \g__str_alias_prop
+\prop_gput:Nnn \g__str_alias_prop { latin1 } { iso88591 }
+\prop_gput:Nnn \g__str_alias_prop { latin2 } { iso88592 }
+\prop_gput:Nnn \g__str_alias_prop { latin3 } { iso88593 }
+\prop_gput:Nnn \g__str_alias_prop { latin4 } { iso88594 }
+\prop_gput:Nnn \g__str_alias_prop { latin5 } { iso88599 }
+\prop_gput:Nnn \g__str_alias_prop { latin6 } { iso885910 }
+\prop_gput:Nnn \g__str_alias_prop { latin7 } { iso885913 }
+\prop_gput:Nnn \g__str_alias_prop { latin8 } { iso885914 }
+\prop_gput:Nnn \g__str_alias_prop { latin9 } { iso885915 }
+\prop_gput:Nnn \g__str_alias_prop { latin10 } { iso885916 }
+\prop_gput:Nnn \g__str_alias_prop { utf16le } { utf16 }
+\prop_gput:Nnn \g__str_alias_prop { utf16be } { utf16 }
+\prop_gput:Nnn \g__str_alias_prop { utf32le } { utf32 }
+\prop_gput:Nnn \g__str_alias_prop { utf32be } { utf32 }
+\prop_gput:Nnn \g__str_alias_prop { hexadecimal } { hex }
+\bool_new:N \g__str_error_bool
+\flag_new:n { str_byte }
+\flag_new:n { str_error }
+\group_begin:
+\char_set_lccode:nn { `\* } { `\  }
+\char_set_lccode:nn { `\A } { `\A }
+\tl_to_lowercase:n
+  {
+    \group_end:
+    \cs_new_protected:Npn \__str_gset_other:Nn #1#2
+      {
+        \tl_gset:Nx #1
+          {
+            \exp_after:wN \__str_gset_other_loop:w \tl_to_str:n {#2} ~ %
+            A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_stop
+          }
+      }
+    \cs_new:Npn \__str_gset_other_loop:w
+      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 ~
+      {
+        \if_meaning:w A #9
+          \__str_gset_other_end:w
+        \fi:
+        #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * #9
+        \__str_gset_other_loop:w *
+      }
+    \cs_new:Npn \__str_gset_other_end:w \fi: #1 * A #2 \q_stop
+      { \fi: #1 }
+  }
+\prg_new_conditional:Npnn \__str_if_contains_char:NN #1#2 { T , TF }
+  {
+    \exp_after:wN \__str_if_contains_char_aux:NN \exp_after:wN #2
+      #1 { \__prg_break:n { ? \fi: } }
+    \__prg_break_point:
+    \prg_return_false:
+  }
+\prg_new_conditional:Npnn \__str_if_contains_char:nN #1#2 { TF }
+  {
+    \__str_if_contains_char_aux:NN #2 #1 { \__prg_break:n { ? \fi: } }
+    \__prg_break_point:
+    \prg_return_false:
+  }
+\cs_new:Npn \__str_if_contains_char_aux:NN #1#2
+  {
+    \if_charcode:w #1 #2
+      \exp_after:wN \__str_if_contains_char_true:
+    \fi:
+    \__str_if_contains_char_aux:NN #1
+  }
+\cs_new_nopar:Npn \__str_if_contains_char_true:
+  { \__prg_break:n { \prg_return_true: \use_none:n } }
+\prg_new_conditional:Npnn \__str_octal_use:N #1 { TF }
+  {
+    \if_int_compare:w \c_one < '1 \token_to_str:N #1 \exp_stop_f:
+      #1 \prg_return_true:
+    \else:
+      \prg_return_false:
+    \fi:
+  }
+\prg_new_conditional:Npnn \__str_hexadecimal_use:N #1 { TF }
+  {
+    \if_int_compare:w \c_two < "1 \token_to_str:N #1 \exp_stop_f:
+      #1 \prg_return_true:
+    \else:
+      \if_case:w \__int_eval:w
+          \exp_after:wN ` \token_to_str:N #1 - `a
+        \__int_eval_end:
+           A
+      \or: B
+      \or: C
+      \or: D
+      \or: E
+      \or: F
+      \else:
+        \prg_return_false:
+        \exp_after:wN \use_none:n
+      \fi:
+      \prg_return_true:
+    \fi:
+  }
+\group_begin:
+  \char_set_catcode_other:n { \c_zero }
+  \tl_set:Nx \l__str_internal_tl { \tl_to_str:n { 0123456789ABCDEF } }
+  \exp_args:No \tl_map_inline:nn { \l__str_internal_tl " }
+    { \char_set_lccode:nn {`#1} { \c_zero } }
+  \tl_map_inline:Nn \l__str_internal_tl
+    {
+      \tl_map_inline:Nn \l__str_internal_tl
+        {
+          \char_set_lccode:nn { \c_zero } {"#1##1}
+          \tl_to_lowercase:n
+            {
+              \tl_const:cx
+                { c__str_byte_ \int_eval:n {"#1##1} _tl }
+                { ^^@ #1 ##1 }
+            }
+        }
+    }
+\group_end:
+\tl_const:cn { c__str_byte_-1_tl } { { } \use_none:n { } }
+\cs_new:Npn \__str_output_byte:n #1
+  { \__str_output_byte:w #1 \__str_output_end: }
+\cs_new_nopar:Npn \__str_output_byte:w
+  {
+    \exp_after:wN \exp_after:wN
+    \exp_after:wN \use_i:nnn
+    \cs:w c__str_byte_ \int_use:N \__int_eval:w
+  }
+\cs_new:Npn \__str_output_hexadecimal:n #1
+  { \__str_output_hexadecimal:w #1 \__str_output_end: }
+\cs_new_nopar:Npn \__str_output_hexadecimal:w
+  {
+    \exp_after:wN \exp_after:wN
+    \exp_after:wN \use_none:n
+    \cs:w c__str_byte_ \int_use:N \__int_eval:w
+  }
+\cs_new_nopar:Npn \__str_output_end:
+  { \__int_eval_end: _tl \cs_end: }
+\cs_new:Npn \__str_output_byte_pair_be:n #1
+  {
+    \exp_args:Nf \__str_output_byte_pair:nnN
+      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use:nn
+  }
+\cs_new:Npn \__str_output_byte_pair_le:n #1
+  {
+    \exp_args:Nf \__str_output_byte_pair:nnN
+      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use_ii_i:nn
+  }
+\cs_new:Npn \__str_output_byte_pair:nnN #1#2#3
+  {
+    #3
+      { \__str_output_byte:n { #1 } }
+      { \__str_output_byte:n { #2 - #1 * "100 } }
+  }
+\cs_new_protected:Npn \__str_convert_gmap:N #1
+  {
+    \tl_gset:Nx \g__str_result_tl
+      {
+        \exp_after:wN \__str_convert_gmap_loop:NN
+        \exp_after:wN #1
+          \g__str_result_tl { ? \__prg_break: }
+        \__prg_break_point:
+      }
+  }
+\cs_new:Npn \__str_convert_gmap_loop:NN #1#2
+  {
+    \use_none:n #2
+    #1#2
+    \__str_convert_gmap_loop:NN #1
+  }
+\cs_new_protected:Npn \__str_convert_gmap_internal:N #1
+  {
+    \tl_gset:Nx \g__str_result_tl
+      {
+        \exp_after:wN \__str_convert_gmap_internal_loop:Nww
+        \exp_after:wN #1
+          \g__str_result_tl \s__tl \q_stop \__prg_break: \s__tl
+        \__prg_break_point:
+      }
+  }
+\cs_new:Npn \__str_convert_gmap_internal_loop:Nww #1 #2 \s__tl #3 \s__tl
+  {
+    \use_none_delimit_by_q_stop:w #3 \q_stop
+    #1 {#3}
+    \__str_convert_gmap_internal_loop:Nww #1
+  }
+\cs_new_protected:Npn \__str_if_flag_error:nnx #1
+  {
+    \flag_if_raised:nTF {#1}
+      { \__msg_kernel_error:nnx { str } }
+      { \use_none:nn }
+  }
+\cs_new_protected:Npn \__str_if_flag_no_error:nnx #1#2#3
+  { \flag_if_raised:nT {#1} { \bool_gset_true:N \g__str_error_bool } }
+\cs_new_protected:Npn \__str_if_flag_times:nT #1#2
+  { \flag_if_raised:nT {#1} { #2~(x \flag_height:n {#1} ) } }
+\cs_new_protected_nopar:Npn \str_set_convert:Nnnn
+  { \__str_convert:nNNnnn { } \tl_set_eq:NN }
+\cs_new_protected_nopar:Npn \str_gset_convert:Nnnn
+  { \__str_convert:nNNnnn { } \tl_gset_eq:NN }
+\prg_new_protected_conditional:Npnn
+    \str_set_convert:Nnnn #1#2#3#4 { T , F , TF }
+  {
+    \bool_gset_false:N \g__str_error_bool
+    \__str_convert:nNNnnn
+      { \cs_set_eq:NN \__str_if_flag_error:nnx \__str_if_flag_no_error:nnx }
+      \tl_set_eq:NN #1 {#2} {#3} {#4}
+    \bool_if:NTF \g__str_error_bool \prg_return_false: \prg_return_true:
+  }
+\prg_new_protected_conditional:Npnn
+    \str_gset_convert:Nnnn #1#2#3#4 { T , F , TF }
+  {
+    \bool_gset_false:N \g__str_error_bool
+    \__str_convert:nNNnnn
+      { \cs_set_eq:NN \__str_if_flag_error:nnx \__str_if_flag_no_error:nnx }
+      \tl_gset_eq:NN #1 {#2} {#3} {#4}
+    \bool_if:NTF \g__str_error_bool \prg_return_false: \prg_return_true:
+  }
+\cs_new_protected:Npn \__str_convert:nNNnnn #1#2#3#4#5#6
+  {
+    \group_begin:
+      #1
+      \__str_gset_other:Nn \g__str_result_tl {#4}
+      \exp_after:wN \__str_convert:wwwnn
+        \tl_to_str:n {#5} /// \q_stop
+        { decode } { unescape }
+        \prg_do_nothing:
+        \__str_convert_decode_:
+      \exp_after:wN \__str_convert:wwwnn
+        \tl_to_str:n {#6} /// \q_stop
+        { encode } { escape }
+        \use_ii_i:nn
+        \__str_convert_encode_:
+    \group_end:
+    #2 #3 \g__str_result_tl
+  }
+\cs_new_protected:Npn \__str_convert:wwwnn
+    #1 / #2 // #3 \q_stop #4#5
+  {
+    \__str_convert:nnn {enc} {#4} {#1}
+    \__str_convert:nnn {esc} {#5} {#2}
+    \exp_args:Ncc \__str_convert:NNnNN
+      { __str_convert_#4_#1: } { __str_convert_#5_#2: } {#2}
+  }
+\cs_new_protected:Npn \__str_convert:NNnNN #1#2#3#4#5
+  {
+    \if_meaning:w #1 #5
+      \tl_if_empty:nF {#3}
+        { \__msg_kernel_error:nnx { str } { native-escaping } {#3} }
+      #1
+    \else:
+      #4 #2 #1
+    \fi:
+  }
+\cs_new_protected:Npn \__str_convert:nnn #1#2#3
+  {
+    \cs_if_exist:cF { __str_convert_#2_#3: }
+      {
+        \exp_args:Nx \__str_convert:nnnn
+          { \__str_convert_lowercase_alphanum:n {#3} }
+          {#1} {#2} {#3}
+      }
+  }
+\cs_new_protected:Npn \__str_convert:nnnn #1#2#3#4
+  {
+    \cs_if_exist:cF { __str_convert_#3_#1: }
+      {
+        \prop_get:NnNF \g__str_alias_prop {#1} \l__str_internal_tl
+          { \tl_set:Nn \l__str_internal_tl {#1} }
+        \cs_if_exist:cF { __str_convert_#3_ \l__str_internal_tl : }
+          {
+            \file_if_exist:nTF { l3str-#2- \l__str_internal_tl .def }
+              {
+                \group_begin:
+                  \__str_load_catcodes:
+                  \file_input:n { l3str-#2- \l__str_internal_tl .def }
+                \group_end:
+              }
+              {
+                \tl_clear:N \l__str_internal_tl
+                \__msg_kernel_error:nnxx { str } { unknown-#2 } {#4} {#1}
+              }
+          }
+        \cs_if_exist:cF { __str_convert_#3_#1: }
+          {
+            \cs_gset_eq:cc { __str_convert_#3_#1: }
+              { __str_convert_#3_ \l__str_internal_tl : }
+          }
+      }
+    \cs_gset_eq:cc { __str_convert_#3_#4: } { __str_convert_#3_#1: }
+  }
+\cs_new:Npn \__str_convert_lowercase_alphanum:n #1
+  {
+    \exp_after:wN \__str_convert_lowercase_alphanum_loop:N
+      \tl_to_str:n {#1} { ? \__prg_break: }
+    \__prg_break_point:
+  }
+\cs_new:Npn \__str_convert_lowercase_alphanum_loop:N #1
+  {
+    \use_none:n #1
+    \if_int_compare:w `#1 < \c_ninety_one
+      \if_int_compare:w `#1 < \c_sixty_five
+        \if_int_compare:w \c_one < 1#1 \exp_stop_f:
+          #1
+        \fi:
+      \else:
+        \__str_output_byte:n { `#1 + \c_thirty_two }
+      \fi:
+    \else:
+      \if_int_compare:w `#1 < \c_one_hundred_twenty_three
+        \if_int_compare:w `#1 < \c_ninety_seven
+        \else:
+          #1
+        \fi:
+      \fi:
+    \fi:
+    \__str_convert_lowercase_alphanum_loop:N
+  }
+\cs_new_protected:Npn \__str_load_catcodes:
+  {
+    \char_set_catcode_escape:N \\
+    \char_set_catcode_group_begin:N \{
+    \char_set_catcode_group_end:N \}
+    \char_set_catcode_math_toggle:N \$
+    \char_set_catcode_alignment:N \&
+    \char_set_catcode_parameter:N \#
+    \char_set_catcode_math_superscript:N \^
+    \char_set_catcode_ignore:N \ %
+    \char_set_catcode_space:N \~
+    \tl_map_function:nN { abcdefghijklmnopqrstuvwxyz_:ABCDEFILNPSTUX }
+      \char_set_catcode_letter:N
+    \tl_map_function:nN { 0123456789"'?*+-.(),`!/<>[];= }
+      \char_set_catcode_other:N
+    \char_set_catcode_comment:N \%
+    \int_set:Nn \tex_endlinechar:D {32}
+  }
+\pdftex_if_engine:TF
+  { \cs_new_eq:NN \__str_filter_bytes:n \use:n }
+  {
+    \cs_new:Npn \__str_filter_bytes:n #1
+      {
+        \__str_filter_bytes_aux:N #1
+          { ? \__prg_break: }
+        \__prg_break_point:
+      }
+    \cs_new:Npn \__str_filter_bytes_aux:N #1
+      {
+        \use_none:n #1
+        \if_int_compare:w `#1 < 256 \exp_stop_f:
+          #1
+        \else:
+          \flag_raise:n { str_byte }
+        \fi:
+        \__str_filter_bytes_aux:N
+      }
+  }
+\pdftex_if_engine:TF
+  { \cs_new_protected_nopar:Npn \__str_convert_unescape_: { } }
+  {
+    \cs_new_protected_nopar:Npn \__str_convert_unescape_:
+      {
+        \flag_clear:n { str_byte }
+        \tl_gset:Nx \g__str_result_tl
+          { \exp_args:No \__str_filter_bytes:n \g__str_result_tl }
+        \__str_if_flag_error:nnx { str_byte } { non-byte } { bytes }
+      }
+  }
+\cs_new_eq:NN \__str_convert_unescape_bytes: \__str_convert_unescape_:
+\cs_new_protected_nopar:Npn \__str_convert_escape_: { }
+\cs_new_eq:NN \__str_convert_escape_bytes: \__str_convert_escape_:
+\cs_new_protected_nopar:Npn \__str_convert_decode_:
+  { \__str_convert_gmap:N \__str_decode_native_char:N }
+\cs_new:Npn \__str_decode_native_char:N #1
+  { #1 \s__tl \__int_value:w `#1 \s__tl }
+\group_begin:
+  \char_set_catcode_other:n { 0 }
+  \pdftex_if_engine:TF
+    {
+      \cs_new_protected_nopar:Npn \__str_convert_encode_:
+        {
+          \flag_clear:n { str_error }
+          \__str_convert_gmap_internal:N \__str_encode_native_char:n
+          \__str_if_flag_error:nnx { str_error }
+            { pdfTeX-native-overflow } { }
+        }
+      \cs_new:Npn \__str_encode_native_char:n #1
+        {
+          \if_int_compare:w #1 < \c_two_hundred_fifty_six
+            \__str_output_byte:n {#1}
+          \else:
+            \flag_raise:n { str_error }
+            ?
+          \fi:
+        }
+      \__msg_kernel_new:nnnn { str } { pdfTeX-native-overflow }
+        { Character~code~too~large~for~pdfTeX. }
+        {
+          The~pdfTeX~engine~only~supports~8-bit~characters:~
+          valid~character~codes~are~in~the~range~[0,255].~
+          To~manipulate~arbitrary~Unicode,~use~LuaTeX~or~XeTeX.
+        }
+    }
+    {
+      \cs_new_protected_nopar:Npn \__str_convert_encode_:
+        {
+          \int_zero:N \l__tl_build_offset_int
+          \__tl_gbuild_x:Nw \g__str_result_tl
+            \exp_after:wN \__str_encode_native_loop:w
+              \g__str_result_tl \s__tl { \q_stop \__prg_break: } \s__tl
+            \__prg_break_point:
+          \__tl_build_end:
+        }
+      \cs_new_protected:Npn \__str_encode_native_loop:w #1 \s__tl #2 \s__tl
+        {
+          \use_none_delimit_by_q_stop:w #2 \q_stop
+          \tex_lccode:D \l__str_internal_int \__int_eval:w #2 \__int_eval_end:
+          \tl_to_lowercase:n { \__tl_build_one:n { ^^@ } }
+          \__str_encode_native_loop:w
+        }
+    }
+\group_end:
+\cs_new_protected:Npn \__str_declare_eight_bit_encoding:nnn #1#2#3
+  {
+    \tl_set:Nn \l__str_internal_tl {#1}
+    \cs_new_protected_nopar:cpn { __str_convert_decode_#1: }
+      { \__str_convert_decode_eight_bit:n {#1} }
+    \cs_new_protected_nopar:cpn { __str_convert_encode_#1: }
+      { \__str_convert_encode_eight_bit:n {#1} }
+    \tl_const:cn { c__str_encoding_#1_tl } {#2}
+    \tl_const:cn { c__str_encoding_#1_missing_tl } {#3}
+  }
+\cs_new_protected:Npn \__str_convert_decode_eight_bit:n #1
+  {
+    \group_begin:
+      \int_zero:N \l__str_internal_int
+      \exp_last_unbraced:Nx \__str_decode_eight_bit_load:nn
+        { \tl_use:c { c__str_encoding_#1_tl } }
+        { \q_stop \__prg_break: } { }
+      \__prg_break_point:
+      \exp_last_unbraced:Nx \__str_decode_eight_bit_load_missing:n
+        { \tl_use:c { c__str_encoding_#1_missing_tl } }
+        { \q_stop \__prg_break: }
+      \__prg_break_point:
+      \flag_clear:n { str_error }
+      \__str_convert_gmap:N \__str_decode_eight_bit_char:N
+      \__str_if_flag_error:nnx { str_error } { decode-8-bit } {#1}
+    \group_end:
+  }
+\cs_new_protected:Npn \__str_decode_eight_bit_load:nn #1#2
+  {
+    \use_none_delimit_by_q_stop:w #1 \q_stop
+    \tex_dimen:D "#1 = \l__str_internal_int sp \scan_stop:
+    \tex_skip:D \l__str_internal_int = "#1 sp \scan_stop:
+    \tex_toks:D \l__str_internal_int \exp_after:wN { \__int_value:w "#2 }
+    \tex_advance:D \l__str_internal_int \c_one
+    \__str_decode_eight_bit_load:nn
+  }
+\cs_new_protected:Npn \__str_decode_eight_bit_load_missing:n #1
+  {
+    \use_none_delimit_by_q_stop:w #1 \q_stop
+    \tex_dimen:D "#1 = \l__str_internal_int sp \scan_stop:
+    \tex_skip:D \l__str_internal_int = "#1 sp \scan_stop:
+    \tex_toks:D \l__str_internal_int \exp_after:wN
+      { \int_use:N \c__str_replacement_char_int }
+    \tex_advance:D \l__str_internal_int \c_one
+    \__str_decode_eight_bit_load_missing:n
+  }
+\cs_new:Npn \__str_decode_eight_bit_char:N #1
+  {
+    #1 \s__tl
+    \if_int_compare:w \tex_dimen:D `#1 < \l__str_internal_int
+      \if_int_compare:w \tex_skip:D \tex_dimen:D `#1 = `#1 \exp_stop_f:
+        \tex_the:D \tex_toks:D \tex_dimen:D
+      \fi:
+    \fi:
+    \__int_value:w `#1 \s__tl
+  }
+\cs_new_protected:Npn \__str_convert_encode_eight_bit:n #1
+  {
+    \group_begin:
+      \int_zero:N \l__str_internal_int
+      \exp_last_unbraced:Nx \__str_encode_eight_bit_load:nn
+        { \tl_use:c { c__str_encoding_#1_tl } }
+        { \q_stop \__prg_break: } { }
+      \__prg_break_point:
+      \flag_clear:n { str_error }
+      \__str_convert_gmap_internal:N \__str_encode_eight_bit_char:n
+      \__str_if_flag_error:nnx { str_error } { encode-8-bit } {#1}
+    \group_end:
+  }
+\cs_new_protected:Npn \__str_encode_eight_bit_load:nn #1#2
+  {
+    \use_none_delimit_by_q_stop:w #1 \q_stop
+    \tex_dimen:D "#2 = \l__str_internal_int sp \scan_stop:
+    \tex_skip:D \l__str_internal_int = "#2 sp \scan_stop:
+    \exp_args:NNf \tex_toks:D \l__str_internal_int
+      { \__str_output_byte:n { "#1 } }
+    \tex_advance:D \l__str_internal_int \c_one
+    \__str_encode_eight_bit_load:nn
+  }
+\cs_new:Npn \__str_encode_eight_bit_char:n #1
+  {
+    \if_int_compare:w #1 > \c_max_register_int
+      \flag_raise:n { str_error }
+    \else:
+      \if_int_compare:w \tex_dimen:D #1 < \l__str_internal_int
+        \if_int_compare:w \tex_skip:D \tex_dimen:D #1 = #1 \exp_stop_f:
+          \tex_the:D \tex_toks:D \tex_dimen:D #1 \exp_stop_f:
+          \exp_after:wN \exp_after:wN \exp_after:wN \use_none:nn
+        \fi:
+      \fi:
+      \__str_encode_eight_bit_char_aux:n {#1}
+    \fi:
+  }
+\cs_new:Npn \__str_encode_eight_bit_char_aux:n #1
+  {
+    \if_int_compare:w #1 < \c_two_hundred_fifty_six
+      \__str_output_byte:n {#1}
+    \else:
+      \flag_raise:n { str_error }
+    \fi:
+  }
+\__msg_kernel_new:nnn { str } { unknown-esc }
+  { Escaping~scheme~'#1'~(filtered:~'#2')~unknown. }
+\__msg_kernel_new:nnn { str } { unknown-enc }
+  { Encoding~scheme~'#1'~(filtered:~'#2')~unknown. }
+\__msg_kernel_new:nnnn { str } { native-escaping }
+  { The~'native'~encoding~scheme~does~not~support~any~escaping. }
+  {
+    Since~native~strings~do~not~consist~in~bytes,~
+    none~of~the~escaping~methods~make~sense.~
+    The~specified~escaping,~'#1',~will be ignored.
+  }
+\__msg_kernel_new:nnn { str } { file-not-found }
+  { File~'l3str-#1.def'~not~found. }
+\pdftex_if_engine:F
+  {
+    \__msg_kernel_new:nnnn { str } { non-byte }
+      { String~invalid~in~escaping~'#1':~it~may~only~contain~bytes. }
+      {
+        Some~characters~in~the~string~you~asked~to~convert~are~not~
+        8-bit~characters.~Perhaps~the~string~is~a~'native'~Unicode~string?~
+        If~it~is,~try~using\\
+        \\
+        \iow_indent:n
+          {
+            \iow_char:N\\str_set_convert:Nnnn \\
+            \ \ <str~var>~\{~<string>~\}~\{~native~\}~\{~<target~encoding>~\}
+          }
+      }
+  }
+\__msg_kernel_new:nnnn { str } { decode-8-bit }
+  { Invalid~string~in~encoding~'#1'. }
+  {
+    LaTeX~came~across~a~byte~which~is~not~defined~to~represent~
+    any~character~in~the~encoding~'#1'.
+  }
+\__msg_kernel_new:nnnn { str } { encode-8-bit }
+  { Unicode~string~cannot~be~converted~to~encoding~'#1'. }
+  {
+    The~encoding~'#1'~only~contains~a~subset~of~all~Unicode~characters.~
+    LaTeX~was~asked~to~convert~a~string~to~that~encoding,~but~that~
+    string~contains~a~character~that~'#1'~does~not~support.
+  }
+%% 
+%%
+%% End of file `l3str-convert.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty
index 57e71f04988..bbf68b78646 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3str-format.dtx Copyright (C) 2012 The LaTeX3 Project
+%% File: l3str-format.dtx Copyright (C) 2012-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -61,6 +61,20 @@
   }
 \cs_new:Npn \__str_format_put:nw #1 #2 \s__stop { #2 \s__stop #1 }
 \cs_generate_variant:Nn \__str_format_put:nw { o , f }
+\prg_new_conditional:Npnn \__str_format_if_in:nN #1#2 { TF }
+  {
+    \__str_format_if_in_aux:NN #2 #1
+      { #2 \prg_return_false: \exp_after:wN \__prg_break: \else: }
+    \__prg_break_point:
+  }
+\cs_new:Npn \__str_format_if_in_aux:NN #1#2
+  {
+    \if_charcode:w #1 #2
+      \prg_return_true:
+      \exp_after:wN \__prg_break:
+    \fi:
+    \__str_format_if_in_aux:NN #1
+  }
 \cs_new:Npn \__str_format_parse:n #1
   {
     \exp_last_unbraced:Nf \__str_format_parse_auxi:NN
@@ -68,7 +82,7 @@
   }
 \cs_new:Npx \__str_format_parse_auxi:NN #1#2
   {
-    \exp_not:N \__str_if_contains_char:nNTF { < > = ^ } #2
+    \exp_not:N \__str_format_if_in:nNTF { < > = ^ } #2
       { \exp_not:N \__str_format_parse_auxiii:nN { #1 #2 } }
       {
         \exp_not:N \__str_format_parse_auxii:nN
@@ -77,13 +91,13 @@
   }
 \cs_new:Npn \__str_format_parse_auxii:nN #1#2
   {
-    \__str_if_contains_char:nNTF { < > = ^ } #2
+    \__str_format_if_in:nNTF { < > = ^ } #2
       { \__str_format_parse_auxiii:nN { #1 #2 } }
       { \__str_format_parse_auxiii:nN { #1 ? } #2 }
   }
 \cs_new:Npx \__str_format_parse_auxiii:nN #1#2
   {
-    \exp_not:N \__str_if_contains_char:nNTF
+    \exp_not:N \__str_format_if_in:nNTF
       { + - \c_catcode_other_space_tl }
       #2
       { \exp_not:N \__str_format_parse_auxiv:nwN { #1 #2 } ; }
@@ -199,8 +213,8 @@
       }
     \__str_format_put:nw { {#4} }
     \tl_if_empty:nTF {#5}
-      { \__str_format_put:nw { \use:n { } } }
-      { \__str_format_put:nw { \__str_substr_unsafe:nnn { {1} {#5} } } }
+      { \__str_format_put:nw { \__str_range_unsafe:nnn { {1} {-1} } } }
+      { \__str_format_put:nw { \__str_range_unsafe:nnn { {1} {#5} } } }
     \token_if_eq_charcode:NNF #6 s
       {
         \token_if_eq_charcode:NNF #6 ?
@@ -384,7 +398,7 @@
           }
           {
             \__str_format_put:fw
-              { \str_substr:nnn { #4#5#6#7 0 } { 2 } { #8 + 1 } }
+              { \str_range:nnn { #4#5#6#7 0 } { 2 } { #8 + 1 } }
           }
         \__str_format_put:fw { \use_i:nnnn #4 . }
         \use_none:n \s__stop
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str.sty
index 8fb7f22b337..15d29def3e8 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3str.dtx Copyright (C) 2011-2012 The LaTeX3 Project
+%% File: l3str.dtx Copyright (C) 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,13 +46,10 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{expl3}
-\GetIdInfo$Id: l3str.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3str.dtx 4452 2013-01-20 10:18:32Z joseph $
   {L3 Experimental strings}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
-\RequirePackage{l3tl-analysis,l3tl-build,l3flag}
-\cs_if_exist:NF \use_ii_i:nn
-  { \cs_new:Npn \use_ii_i:nn #1#2 { #2 #1 } }
 \cs_new_eq:NN \str_new:N \tl_new:N
 \cs_generate_variant:Nn \str_new:N { c }
 \tl_map_inline:nn
@@ -70,95 +67,17 @@
       { \exp_not:c { tl_ #1 :Nx } ##1 { \exp_not:N \tl_to_str:n {##2} } }
     \exp_args:Nc \cs_generate_variant:Nn { str_ #1 :Nn } { Nx , cn , cx }
   }
-\cs_new_protected_nopar:Npn \__str_tmp:w { }
-\tl_new:N \l__str_internal_tl
-\int_new:N \l__str_internal_int
-\tl_new:N \g__str_result_tl
-\int_const:Nn \c_forty_eight  { 48 }
-\int_const:Nn \c_fifty_eight  { 58 }
-\int_const:Nn \c_sixty_five   { 65 }
-\int_const:Nn \c_ninety_one   { 91 }
-\int_const:Nn \c_ninety_seven { 97 }
-\int_const:Nn \c_one_hundred_twenty_three { 123 }
-\int_const:Nn \c_one_hundred_twenty_seven { 127 }
-\int_const:Nn \c_max_char_int
-  { \pdftex_if_engine:TF { "FF } { "10FFFF } }
-\int_const:Nn \c__str_replacement_char_int { "FFFD }
-\tl_const:Nx \c_backslash_str { \cs_to_str:N \\ }
-\tl_const:Nx \c_lbrace_str    { \cs_to_str:N \{ }
-\tl_const:Nx \c_rbrace_str    { \cs_to_str:N \} }
-\tl_const:Nx \c_hash_str      { \cs_to_str:N \# }
-\tl_const:Nx \c_tilde_str     { \cs_to_str:N \~ }
-\tl_const:Nx \c_percent_str   { \cs_to_str:N \% }
-\prop_new:N \g__str_alias_prop
-\prop_gput:Nnn \g__str_alias_prop { latin1 } { iso88591 }
-\prop_gput:Nnn \g__str_alias_prop { latin2 } { iso88592 }
-\prop_gput:Nnn \g__str_alias_prop { latin3 } { iso88593 }
-\prop_gput:Nnn \g__str_alias_prop { latin4 } { iso88594 }
-\prop_gput:Nnn \g__str_alias_prop { latin5 } { iso88599 }
-\prop_gput:Nnn \g__str_alias_prop { latin6 } { iso885910 }
-\prop_gput:Nnn \g__str_alias_prop { latin7 } { iso885913 }
-\prop_gput:Nnn \g__str_alias_prop { latin8 } { iso885914 }
-\prop_gput:Nnn \g__str_alias_prop { latin9 } { iso885915 }
-\prop_gput:Nnn \g__str_alias_prop { latin10 } { iso885916 }
-\prop_gput:Nnn \g__str_alias_prop { utf16le } { utf16 }
-\prop_gput:Nnn \g__str_alias_prop { utf16be } { utf16 }
-\prop_gput:Nnn \g__str_alias_prop { utf32le } { utf32 }
-\prop_gput:Nnn \g__str_alias_prop { utf32be } { utf32 }
-\prop_gput:Nnn \g__str_alias_prop { hexadecimal } { hex }
-\bool_new:N \g__str_error_bool
-\flag_new:n { str_byte }
-\flag_new:n { str_error }
-\group_begin:
-\char_set_lccode:nn { `\* } { `\  }
-\char_set_lccode:nn { `\A } { `\A }
-\tl_to_lowercase:n
-  {
-    \group_end:
-    \cs_new:Npn \__str_to_other:n #1
-      {
-        \exp_after:wN \__str_to_other_loop:w \tl_to_str:n {#1} ~ %
-        A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_mark \q_stop
-      }
-    \cs_new:Npn \__str_to_other_loop:w
-      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 \q_stop
-      {
-        \if_meaning:w A #8
-          \__str_to_other_end:w
-        \fi:
-        \__str_to_other_loop:w
-        #9 #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * \q_stop
-      }
-    \cs_new:Npn \__str_to_other_end:w \fi: #1 \q_mark #2 * A #3 \q_stop
-      { \fi: #2 }
-  }
-\group_begin:
-\char_set_lccode:nn { `\* } { `\  }
-\char_set_lccode:nn { `\A } { `\A }
-\tl_to_lowercase:n
-  {
-    \group_end:
-    \cs_new_protected:Npn \__str_gset_other:Nn #1#2
-      {
-        \tl_gset:Nx #1
-          {
-            \exp_after:wN \__str_gset_other_loop:w \tl_to_str:n {#2} ~ %
-            A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_stop
-          }
-      }
-    \cs_new:Npn \__str_gset_other_loop:w
-      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 ~
-      {
-        \if_meaning:w A #9
-          \__str_gset_other_end:w
-        \fi:
-        #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * #9
-        \__str_gset_other_loop:w *
-      }
-    \cs_new:Npn \__str_gset_other_end:w \fi: #1 * A #2 \q_stop
-      { \fi: #1 }
-  }
-\cs_new:Npn \str_count_spaces:N
+\str_const:Nx \c_backslash_str { \cs_to_str:N \\ }
+\str_const:Nx \c_left_brace_str  { \cs_to_str:N \{ }
+\str_const:Nx \c_right_brace_str { \cs_to_str:N \} }
+\str_const:Nx \c_hash_str      { \cs_to_str:N \# }
+\str_const:Nx \c_tilde_str     { \cs_to_str:N \~ }
+\str_const:Nx \c_percent_str   { \cs_to_str:N \% }
+\str_new:N \l_tmpa_str
+\str_new:N \l_tmpb_str
+\str_new:N \g_tmpa_str
+\str_new:N \g_tmpb_str
+\cs_new_nopar:Npn \str_count_spaces:N
   { \exp_args:No \str_count_spaces:n }
 \cs_new:Npn \str_count_spaces:n #1
   {
@@ -173,7 +92,7 @@
 \cs_new:Npn \__str_count_spaces_loop:wwwwwwwww #1~#2~#3~#4~#5~#6~#7~#8~#9~
   {
     \if_meaning:w X #9
-      \exp_after:wN \use_none_delimit_by_q_stop:w
+      \use_i_delimit_by_q_stop:nw
     \fi:
     \c_nine + \__str_count_spaces_loop:wwwwwwwww
   }
@@ -239,12 +158,35 @@
 \cs_new:Npn \str_tail_ignore_spaces:n #1
   {
     \exp_after:wN \__str_tail_auxii:w
-    \tl_to_str:n {#1} X X \q_stop
+    \tl_to_str:n {#1} \q_mark \q_mark \q_stop
+  }
+\cs_new:Npn \__str_tail_auxii:w #1 #2 \q_mark #3 \q_stop { #2 }
+\group_begin:
+\char_set_lccode:nn { `\* } { `\  }
+\char_set_lccode:nn { `\A } { `\A }
+\tl_to_lowercase:n
+  {
+    \group_end:
+    \cs_new:Npn \__str_to_other:n #1
+      {
+        \exp_after:wN \__str_to_other_loop:w \tl_to_str:n {#1} ~ %
+        A ~ A ~ A ~ A ~ A ~ A ~ A ~ A ~ \q_mark \q_stop
+      }
+    \cs_new:Npn \__str_to_other_loop:w
+      #1 ~ #2 ~ #3 ~ #4 ~ #5 ~ #6 ~ #7 ~ #8 ~ #9 \q_stop
+      {
+        \if_meaning:w A #8
+          \__str_to_other_end:w
+        \fi:
+        \__str_to_other_loop:w
+        #9 #1 * #2 * #3 * #4 * #5 * #6 * #7 * #8 * \q_stop
+      }
+    \cs_new:Npn \__str_to_other_end:w \fi: #1 \q_mark #2 * A #3 \q_stop
+      { \fi: #2 }
   }
-\cs_new:Npn \__str_tail_auxii:w #1 #2 X #3 \q_stop { #2 }
 \cs_new:Npn \__str_skip_c_zero:w #1;
   {
-    \if_int_compare:w \__int_eval:w #1 > \c_eight
+    \if_int_compare:w #1 > \c_eight
       \exp_after:wN \__str_skip_loop:wNNNNNNNN
     \else:
       \exp_after:wN \__str_skip_end:w
@@ -257,16 +199,11 @@
 \cs_new:Npn \__str_skip_end:w #1 ;
   {
     \exp_after:wN \__str_skip_end:NNNNNNNN
-    \if_case:w \if_int_compare:w #1 > \c_zero #1 \else: 0 \fi: \exp_stop_f:
-    \or: \or: \or: \or: \or: \or: \or: \or:
+    \if_case:w #1 \exp_stop_f: \or: \or: \or: \or: \or: \or: \or: \or:
   }
 \cs_new:Npn \__str_skip_end:NNNNNNNN #1#2#3#4#5#6#7#8 { \fi: \c_zero }
 \cs_new:Npn \__str_collect_delimit_by_q_stop:w #1;
-  {
-    \exp_after:wN \__str_collect_loop:wn
-    \int_use:N \__int_eval:w #1 ;
-    { }
-  }
+  { \__str_collect_loop:wn #1 ; { } }
 \cs_new:Npn \__str_collect_loop:wn #1 ;
   {
     \if_int_compare:w #1 > \c_seven
@@ -306,8 +243,7 @@
     \exp_after:wN \__str_item:ww
     \int_use:N \__int_eval:w #2 \exp_after:wN ;
     \__int_value:w \__str_count_unsafe:n {#1} ;
-      { } #1
-    \q_stop
+    #1 \q_stop
   }
 \cs_new:Npn \__str_item:ww #1; #2;
   {
@@ -317,7 +253,8 @@
           { \use_none_delimit_by_q_stop:w }
           {
             \exp_after:wN \use_i_delimit_by_q_stop:nw
-            \tex_romannumeral:D \__str_skip_c_zero:w #1 + #2 + \c_one ;
+            \tex_romannumeral:D \exp_after:wN \__str_skip_c_zero:w
+              \int_use:N \__int_eval:w #1 + #2 ;
           }
       }
       {
@@ -325,590 +262,80 @@
           { \use_none_delimit_by_q_stop:w }
           {
             \exp_after:wN \use_i_delimit_by_q_stop:nw
-            \tex_romannumeral:D \__str_skip_c_zero:w #1 ;
+            \tex_romannumeral:D \__str_skip_c_zero:w #1 ; { }
           }
       }
   }
-\cs_new_nopar:Npn \str_substr:Nnn { \exp_args:No \str_substr:nnn }
-\cs_new:Npn \str_substr:nnn #1#2#3
-  {
-    \exp_args:Nf \tl_to_str:n
-      {
-        \exp_args:Nf \__str_substr_unsafe:nnn
-          { \__str_to_other:n {#1} } {#2} {#3}
-      }
-  }
-\cs_new:Npn \str_substr_ignore_spaces:nnn #1
-  { \exp_args:No \__str_substr_unsafe:nnn { \tl_to_str:n {#1} } }
-\cs_new:Npn \__str_substr_unsafe:nnn #1#2#3
-  {
-    \exp_after:wN \__str_substr:www
-    \__int_value:w \__str_count_unsafe:n {#1} \exp_after:wN ;
-    \int_use:N \__int_eval:w #2 + \c_zero \exp_after:wN ;
-    \int_use:N \__int_eval:w
-      \exp_args:Nf \__str_substr:nN {#3} \c_max_int ;
-      { } #1
-    \q_stop
-  }
-\cs_new:Npn \__str_substr:nN #1 #2
-  { \tl_if_empty:nTF {#1} {#2} {#1} }
-\cs_new:Npn \__str_substr:www #1; #2; #3;
-  {
-    \exp_args:Nf \__str_substr:nnw
-      { \__str_substr_normalize_range:nn {#2} {#1} }
-      { \__str_substr_normalize_range:nn {#3} {#1} }
-  }
-\cs_new:Npn \__str_substr:nnw #1#2
-  {
-    \exp_after:wN \__str_collect_delimit_by_q_stop:w
-    \int_use:N \__int_eval:w #2 + \c_one - #1 \exp_after:wN ;
-    \tex_romannumeral:D \__str_skip_c_zero:w #1 ;
-  }
-\cs_new:Npn \__str_substr_normalize_range:nn #1#2
+\cs_new:Npn \__str_range_normalize:nn #1#2
   {
     \int_eval:n
       {
         \if_int_compare:w #1 < \c_zero
-          \if_int_compare:w #1 < - #2 \exp_stop_f:
+          \if_int_compare:w #1 < -#2 \exp_stop_f:
             \c_zero
           \else:
             #1 + #2 + \c_one
           \fi:
         \else:
-          \if_int_compare:w #1 > #2 \exp_stop_f:
-            #2
-          \else:
+          \if_int_compare:w #1 < #2 \exp_stop_f:
             #1
+          \else:
+            #2
           \fi:
         \fi:
       }
   }
-\prg_new_conditional:Npnn \str_if_eq:NN #1#2 { p , TF , T , F }
-  {
-    \if_int_compare:w \pdftex_strcmp:D { \tl_to_str:N #1 } { \tl_to_str:N #2 }
-      = \c_zero \prg_return_true: \else: \prg_return_false: \fi:
-  }
-\prg_new_conditional:Npnn \__str_if_contains_char:NN #1#2 { T , TF }
+\cs_new_nopar:Npn \str_range:Nnn { \exp_args:No \str_range:nnn }
+\cs_new:Npn \str_range:nnn #1#2#3
   {
-    \exp_after:wN \__str_if_contains_char_aux:NN \exp_after:wN #2
-      #1 { \__prg_break:n { ? \fi: } }
-    \__prg_break_point:
-    \prg_return_false:
+    \exp_args:Nf \tl_to_str:n
+      {
+        \exp_args:Nf \__str_range_unsafe:nnn
+          { \__str_to_other:n {#1} } {#2} {#3}
+      }
   }
-\prg_new_conditional:Npnn \__str_if_contains_char:nN #1#2 { TF }
+\cs_new:Npn \str_range_ignore_spaces:nnn #1
+  { \exp_args:No \__str_range_unsafe:nnn { \tl_to_str:n {#1} } }
+\cs_new:Npn \__str_range_unsafe:nnn #1#2#3
   {
-    \__str_if_contains_char_aux:NN #2 #1 { \__prg_break:n { ? \fi: } }
-    \__prg_break_point:
-    \prg_return_false:
+    \exp_after:wN \__str_range:www
+    \__int_value:w \__str_count_unsafe:n {#1} \exp_after:wN ;
+    \int_use:N \__int_eval:w #2 - \c_one \exp_after:wN ;
+    \int_use:N \__int_eval:w #3 ;
+    #1 \q_stop
   }
-\cs_new:Npn \__str_if_contains_char_aux:NN #1#2
+\cs_new:Npn \__str_range:www #1; #2; #3;
   {
-    \if_charcode:w #1 #2
-      \exp_after:wN \__str_if_contains_char_true:
-    \fi:
-    \__str_if_contains_char_aux:NN #1
+    \exp_args:Nf \__str_range:nnw
+      { \__str_range_normalize:nn {#2} {#1} }
+      { \__str_range_normalize:nn {#3} {#1} }
   }
-\cs_new_nopar:Npn \__str_if_contains_char_true:
-  { \__prg_break:n { \prg_return_true: \use_none:n } }
-\prg_new_conditional:Npnn \__str_octal_use:N #1 { TF }
+\cs_new:Npn \__str_range:nnw #1#2
   {
-    \if_int_compare:w \c_one < '1 \token_to_str:N #1 \exp_stop_f:
-      #1 \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
+    \exp_after:wN \__str_collect_delimit_by_q_stop:w
+    \int_use:N \__int_eval:w #2 - #1 \exp_after:wN ;
+    \tex_romannumeral:D \__str_skip_c_zero:w #1 ;
   }
-\prg_new_conditional:Npnn \__str_hexadecimal_use:N #1 { TF }
+\prg_new_conditional:Npnn \str_if_eq:NN #1#2 { p , TF , T , F }
   {
-    \if_int_compare:w \c_two < "1 \token_to_str:N #1 \exp_stop_f:
-      #1 \prg_return_true:
-    \else:
-      \if_case:w \__int_eval:w
-          \exp_after:wN ` \token_to_str:N #1 - `a
-        \__int_eval_end:
-           A
-      \or: B
-      \or: C
-      \or: D
-      \or: E
-      \or: F
-      \else:
-        \prg_return_false:
-        \exp_after:wN \use_none:n
-      \fi:
-      \prg_return_true:
-    \fi:
+    \if_int_compare:w \pdftex_strcmp:D { \tl_to_str:N #1 } { \tl_to_str:N #2 }
+      = \c_zero \prg_return_true: \else: \prg_return_false: \fi:
   }
 \cs_new_eq:NN \str_show:n \tl_show:n
 \cs_new_eq:NN \str_show:N \tl_show:N
 \cs_generate_variant:Nn \str_show:N { c }
-\group_begin:
-  \char_set_catcode_other:n { \c_zero }
-  \tl_set:Nx \l__str_internal_tl { \tl_to_str:n { 0123456789ABCDEF } }
-  \exp_args:No \tl_map_inline:nn { \l__str_internal_tl " }
-    { \char_set_lccode:nn {`#1} { \c_zero } }
-  \tl_map_inline:Nn \l__str_internal_tl
-    {
-      \tl_map_inline:Nn \l__str_internal_tl
-        {
-          \char_set_lccode:nn { \c_zero } {"#1##1}
-          \tl_to_lowercase:n
-            {
-              \tl_const:cx
-                { c__str_byte_ \int_eval:n {"#1##1} _tl }
-                { ^^@ #1 ##1 }
-            }
-        }
-    }
-\group_end:
-\tl_const:cn { c__str_byte_-1_tl } { { } \use_none:n { } }
-\cs_new:Npn \__str_output_byte:n #1
-  { \__str_output_byte:w #1 \__str_output_end: }
-\cs_new_nopar:Npn \__str_output_byte:w
-  {
-    \exp_after:wN \exp_after:wN
-    \exp_after:wN \use_i:nnn
-    \cs:w c__str_byte_ \int_use:N \__int_eval:w
-  }
-\cs_new:Npn \__str_output_hexadecimal:n #1
-  { \__str_output_hexadecimal:w #1 \__str_output_end: }
-\cs_new_nopar:Npn \__str_output_hexadecimal:w
-  {
-    \exp_after:wN \exp_after:wN
-    \exp_after:wN \use_none:n
-    \cs:w c__str_byte_ \int_use:N \__int_eval:w
-  }
-\cs_new_nopar:Npn \__str_output_end:
-  { \__int_eval_end: _tl \cs_end: }
-\cs_new:Npn \__str_output_byte_pair_be:n #1
-  {
-    \exp_args:Nf \__str_output_byte_pair:nnN
-      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use:nn
-  }
-\cs_new:Npn \__str_output_byte_pair_le:n #1
-  {
-    \exp_args:Nf \__str_output_byte_pair:nnN
-      { \int_div_truncate:nn { #1 } { "100 } } {#1} \use_ii_i:nn
-  }
-\cs_new:Npn \__str_output_byte_pair:nnN #1#2#3
-  {
-    #3
-      { \__str_output_byte:n { #1 } }
-      { \__str_output_byte:n { #2 - #1 * "100 } }
-  }
-\cs_new_protected:Npn \__str_convert_gmap:N #1
-  {
-    \tl_gset:Nx \g__str_result_tl
-      {
-        \exp_after:wN \__str_convert_gmap_loop:NN
-        \exp_after:wN #1
-          \g__str_result_tl { ? \__prg_break: }
-        \__prg_break_point:
-      }
-  }
-\cs_new:Npn \__str_convert_gmap_loop:NN #1#2
-  {
-    \use_none:n #2
-    #1#2
-    \__str_convert_gmap_loop:NN #1
-  }
-\cs_new_protected:Npn \__str_convert_gmap_internal:N #1
-  {
-    \tl_gset:Nx \g__str_result_tl
-      {
-        \exp_after:wN \__str_convert_gmap_internal_loop:Nww
-        \exp_after:wN #1
-          \g__str_result_tl \s__tl \q_stop \__prg_break: \s__tl
-        \__prg_break_point:
-      }
-  }
-\cs_new:Npn \__str_convert_gmap_internal_loop:Nww #1 #2 \s__tl #3 \s__tl
-  {
-    \use_none_delimit_by_q_stop:w #3 \q_stop
-    #1 {#3}
-    \__str_convert_gmap_internal_loop:Nww #1
-  }
-\cs_new_protected:Npn \__str_if_flag_error:nnx #1
-  {
-    \flag_if_raised:nTF {#1}
-      { \__msg_kernel_error:nnx { str } }
-      { \use_none:nn }
-  }
-\cs_new_protected:Npn \__str_if_flag_no_error:nnx #1#2#3
-  { \flag_if_raised:nT {#1} { \bool_gset_true:N \g__str_error_bool } }
-\cs_new_protected:Npn \__str_if_flag_times:nT #1#2
-  { \flag_if_raised:nT {#1} { #2~(x \flag_height:n {#1} ) } }
-\cs_new_protected_nopar:Npn \str_set_convert:Nnnn
-  { \__str_convert:nNNnnn { } \tl_set_eq:NN }
-\cs_new_protected_nopar:Npn \str_gset_convert:Nnnn
-  { \__str_convert:nNNnnn { } \tl_gset_eq:NN }
-\prg_new_protected_conditional:Npnn
-    \str_set_convert:Nnnn #1#2#3#4 { T , F , TF }
-  {
-    \bool_gset_false:N \g__str_error_bool
-    \__str_convert:nNNnnn
-      { \cs_set_eq:NN \__str_if_flag_error:nnx \__str_if_flag_no_error:nnx }
-      \tl_set_eq:NN #1 {#2} {#3} {#4}
-    \bool_if:NTF \g__str_error_bool \prg_return_false: \prg_return_true:
-  }
-\prg_new_protected_conditional:Npnn
-    \str_gset_convert:Nnnn #1#2#3#4 { T , F , TF }
-  {
-    \bool_gset_false:N \g__str_error_bool
-    \__str_convert:nNNnnn
-      { \cs_set_eq:NN \__str_if_flag_error:nnx \__str_if_flag_no_error:nnx }
-      \tl_gset_eq:NN #1 {#2} {#3} {#4}
-    \bool_if:NTF \g__str_error_bool \prg_return_false: \prg_return_true:
-  }
-\cs_new_protected:Npn \__str_convert:nNNnnn #1#2#3#4#5#6
-  {
-    \group_begin:
-      #1
-      \__str_gset_other:Nn \g__str_result_tl {#4}
-      \exp_after:wN \__str_convert:wwwnn
-        \tl_to_str:n {#5} /// \q_stop
-        { decode } { unescape }
-        \prg_do_nothing:
-        \__str_convert_decode_:
-      \exp_after:wN \__str_convert:wwwnn
-        \tl_to_str:n {#6} /// \q_stop
-        { encode } { escape }
-        \use_ii_i:nn
-        \__str_convert_encode_:
-    \group_end:
-    #2 #3 \g__str_result_tl
-  }
-\cs_new_protected:Npn \__str_convert:wwwnn
-    #1 / #2 // #3 \q_stop #4#5
-  {
-    \__str_convert:nnn {enc} {#4} {#1}
-    \__str_convert:nnn {esc} {#5} {#2}
-    \exp_args:Ncc \__str_convert:NNnNN
-      { __str_convert_#4_#1: } { __str_convert_#5_#2: } {#2}
-  }
-\cs_new_protected:Npn \__str_convert:NNnNN #1#2#3#4#5
-  {
-    \if_meaning:w #1 #5
-      \tl_if_empty:nF {#3}
-        { \__msg_kernel_error:nnx { str } { native-escaping } {#3} }
-      #1
-    \else:
-      #4 #2 #1
-    \fi:
-  }
-\cs_new_protected:Npn \__str_convert:nnn #1#2#3
-  {
-    \cs_if_exist:cF { __str_convert_#2_#3: }
-      {
-        \exp_args:Nx \__str_convert:nnnn
-          { \__str_convert_lowercase_alphanum:n {#3} }
-          {#1} {#2} {#3}
-      }
-  }
-\cs_new_protected:Npn \__str_convert:nnnn #1#2#3#4
-  {
-    \cs_if_exist:cF { __str_convert_#3_#1: }
-      {
-        \prop_get:NnNF \g__str_alias_prop {#1} \l__str_internal_tl
-          { \tl_set:Nn \l__str_internal_tl {#1} }
-        \cs_if_exist:cF { __str_convert_#3_ \l__str_internal_tl : }
-          {
-            \file_if_exist:nTF { l3str-#2- \l__str_internal_tl .def }
-              {
-                \group_begin:
-                  \__str_load_catcodes:
-                  \file_input:n { l3str-#2- \l__str_internal_tl .def }
-                \group_end:
-              }
-              {
-                \tl_clear:N \l__str_internal_tl
-                \__msg_kernel_error:nnxx { str } { unknown-#2 } {#4} {#1}
-              }
-          }
-        \cs_if_exist:cF { __str_convert_#3_#1: }
-          {
-            \cs_gset_eq:cc { __str_convert_#3_#1: }
-              { __str_convert_#3_ \l__str_internal_tl : }
-          }
-      }
-    \cs_gset_eq:cc { __str_convert_#3_#4: } { __str_convert_#3_#1: }
-  }
-\cs_new:Npn \__str_convert_lowercase_alphanum:n #1
-  {
-    \exp_after:wN \__str_convert_lowercase_alphanum_loop:N
-      \tl_to_str:n {#1} { ? \__prg_break: }
-    \__prg_break_point:
-  }
-\cs_new:Npn \__str_convert_lowercase_alphanum_loop:N #1
-  {
-    \use_none:n #1
-    \if_int_compare:w `#1 < \c_ninety_one
-      \if_int_compare:w `#1 < \c_sixty_five
-        \if_int_compare:w \c_one < 1#1 \exp_stop_f:
-          #1
-        \fi:
-      \else:
-        \__str_output_byte:n { `#1 + \c_thirty_two }
-      \fi:
-    \else:
-      \if_int_compare:w `#1 < \c_one_hundred_twenty_three
-        \if_int_compare:w `#1 < \c_ninety_seven
-        \else:
-          #1
-        \fi:
-      \fi:
-    \fi:
-    \__str_convert_lowercase_alphanum_loop:N
-  }
-\cs_new_protected:Npn \__str_load_catcodes:
-  {
-    \char_set_catcode_escape:N \\
-    \char_set_catcode_group_begin:N \{
-    \char_set_catcode_group_end:N \}
-    \char_set_catcode_math_toggle:N \$
-    \char_set_catcode_alignment:N \&
-    \char_set_catcode_parameter:N \#
-    \char_set_catcode_math_superscript:N \^
-    \char_set_catcode_ignore:N \ %
-    \char_set_catcode_space:N \~
-    \tl_map_function:nN { abcdefghijklmnopqrstuvwxyz_:ABCDEFILNPSTUX }
-      \char_set_catcode_letter:N
-    \tl_map_function:nN { 0123456789"'?*+-.(),`!/<>[];= }
-      \char_set_catcode_other:N
-    \char_set_catcode_comment:N \%
-    \int_set:Nn \tex_endlinechar:D {32}
-  }
-\pdftex_if_engine:TF
-  { \cs_new_eq:NN \__str_filter_bytes:n \use:n }
-  {
-    \cs_new:Npn \__str_filter_bytes:n #1
-      {
-        \__str_filter_bytes_aux:N #1
-          { ? \__prg_break: }
-        \__prg_break_point:
-      }
-    \cs_new:Npn \__str_filter_bytes_aux:N #1
-      {
-        \use_none:n #1
-        \if_int_compare:w `#1 < 256 \exp_stop_f:
-          #1
-        \else:
-          \flag_raise:n { str_byte }
-        \fi:
-        \__str_filter_bytes_aux:N
-      }
-  }
-\pdftex_if_engine:TF
-  { \cs_new_protected_nopar:Npn \__str_convert_unescape_: { } }
-  {
-    \cs_new_protected_nopar:Npn \__str_convert_unescape_:
-      {
-        \flag_clear:n { str_byte }
-        \tl_gset:Nx \g__str_result_tl
-          { \exp_args:No \__str_filter_bytes:n \g__str_result_tl }
-        \__str_if_flag_error:nnx { str_byte } { non-byte } { bytes }
-      }
-  }
-\cs_new_eq:NN \__str_convert_unescape_bytes: \__str_convert_unescape_:
-\cs_new_protected_nopar:Npn \__str_convert_escape_: { }
-\cs_new_eq:NN \__str_convert_escape_bytes: \__str_convert_escape_:
-\cs_new_protected_nopar:Npn \__str_convert_decode_:
-  { \__str_convert_gmap:N \__str_decode_native_char:N }
-\cs_new:Npn \__str_decode_native_char:N #1
-  { #1 \s__tl \__int_value:w `#1 \s__tl }
-\group_begin:
-  \char_set_catcode_other:n { 0 }
-  \pdftex_if_engine:TF
-    {
-      \cs_new_protected_nopar:Npn \__str_convert_encode_:
-        {
-          \flag_clear:n { str_error }
-          \__str_convert_gmap_internal:N \__str_encode_native_char:n
-          \__str_if_flag_error:nnx { str_error }
-            { pdfTeX-native-overflow } { }
-        }
-      \cs_new:Npn \__str_encode_native_char:n #1
-        {
-          \if_int_compare:w #1 < \c_two_hundred_fifty_six
-            \__str_output_byte:n {#1}
-          \else:
-            \flag_raise:n { str_error }
-            ?
-          \fi:
-        }
-      \__msg_kernel_new:nnnn { str } { pdfTeX-native-overflow }
-        { Character~code~too~large~for~pdfTeX. }
-        {
-          The~pdfTeX~engine~only~supports~8-bit~characters:~
-          valid~character~codes~are~in~the~range~[0,255].~
-          To~manipulate~arbitrary~Unicode,~use~LuaTeX~or~XeTeX.
-        }
-    }
-    {
-      \cs_new_protected_nopar:Npn \__str_convert_encode_:
-        {
-          \int_zero:N \l__tl_build_offset_int
-          \__tl_gbuild_x:Nw \g__str_result_tl
-            \exp_after:wN \__str_encode_native_loop:w
-              \g__str_result_tl \s__tl { \q_stop \__prg_break: } \s__tl
-            \__prg_break_point:
-          \__tl_build_end:
-        }
-      \cs_new_protected:Npn \__str_encode_native_loop:w #1 \s__tl #2 \s__tl
-        {
-          \use_none_delimit_by_q_stop:w #2 \q_stop
-          \tex_lccode:D \l__str_internal_int \__int_eval:w #2 \__int_eval_end:
-          \tl_to_lowercase:n { \__tl_build_one:n { ^^@ } }
-          \__str_encode_native_loop:w
-        }
-    }
-\group_end:
-\cs_new_protected:Npn \__str_declare_eight_bit_encoding:nnn #1#2#3
-  {
-    \tl_set:Nn \l__str_internal_tl {#1}
-    \cs_new_protected_nopar:cpn { __str_convert_decode_#1: }
-      { \__str_convert_decode_eight_bit:n {#1} }
-    \cs_new_protected_nopar:cpn { __str_convert_encode_#1: }
-      { \__str_convert_encode_eight_bit:n {#1} }
-    \tl_const:cn { c__str_encoding_#1_tl } {#2}
-    \tl_const:cn { c__str_encoding_#1_missing_tl } {#3}
-  }
-\cs_new_protected:Npn \__str_convert_decode_eight_bit:n #1
-  {
-    \group_begin:
-      \int_zero:N \l__str_internal_int
-      \exp_last_unbraced:Nx \__str_decode_eight_bit_load:nn
-        { \tl_use:c { c__str_encoding_#1_tl } }
-        { \q_stop \__prg_break: } { }
-      \__prg_break_point:
-      \exp_last_unbraced:Nx \__str_decode_eight_bit_load_missing:n
-        { \tl_use:c { c__str_encoding_#1_missing_tl } }
-        { \q_stop \__prg_break: }
-      \__prg_break_point:
-      \flag_clear:n { str_error }
-      \__str_convert_gmap:N \__str_decode_eight_bit_char:N
-      \__str_if_flag_error:nnx { str_error } { decode-8-bit } {#1}
-    \group_end:
-  }
-\cs_new_protected:Npn \__str_decode_eight_bit_load:nn #1#2
-  {
-    \use_none_delimit_by_q_stop:w #1 \q_stop
-    \tex_dimen:D "#1 = \l__str_internal_int sp \scan_stop:
-    \tex_skip:D \l__str_internal_int = "#1 sp \scan_stop:
-    \tex_toks:D \l__str_internal_int \exp_after:wN { \__int_value:w "#2 }
-    \tex_advance:D \l__str_internal_int \c_one
-    \__str_decode_eight_bit_load:nn
-  }
-\cs_new_protected:Npn \__str_decode_eight_bit_load_missing:n #1
-  {
-    \use_none_delimit_by_q_stop:w #1 \q_stop
-    \tex_dimen:D "#1 = \l__str_internal_int sp \scan_stop:
-    \tex_skip:D \l__str_internal_int = "#1 sp \scan_stop:
-    \tex_toks:D \l__str_internal_int \exp_after:wN
-      { \int_use:N \c__str_replacement_char_int }
-    \tex_advance:D \l__str_internal_int \c_one
-    \__str_decode_eight_bit_load_missing:n
-  }
-\cs_new:Npn \__str_decode_eight_bit_char:N #1
-  {
-    #1 \s__tl
-    \if_int_compare:w \tex_dimen:D `#1 < \l__str_internal_int
-      \if_int_compare:w \tex_skip:D \tex_dimen:D `#1 = `#1 \exp_stop_f:
-        \tex_the:D \tex_toks:D \tex_dimen:D
-      \fi:
-    \fi:
-    \__int_value:w `#1 \s__tl
-  }
-\cs_new_protected:Npn \__str_convert_encode_eight_bit:n #1
-  {
-    \group_begin:
-      \int_zero:N \l__str_internal_int
-      \exp_last_unbraced:Nx \__str_encode_eight_bit_load:nn
-        { \tl_use:c { c__str_encoding_#1_tl } }
-        { \q_stop \__prg_break: } { }
-      \__prg_break_point:
-      \flag_clear:n { str_error }
-      \__str_convert_gmap_internal:N \__str_encode_eight_bit_char:n
-      \__str_if_flag_error:nnx { str_error } { encode-8-bit } {#1}
-    \group_end:
-  }
-\cs_new_protected:Npn \__str_encode_eight_bit_load:nn #1#2
-  {
-    \use_none_delimit_by_q_stop:w #1 \q_stop
-    \tex_dimen:D "#2 = \l__str_internal_int sp \scan_stop:
-    \tex_skip:D \l__str_internal_int = "#2 sp \scan_stop:
-    \exp_args:NNf \tex_toks:D \l__str_internal_int
-      { \__str_output_byte:n { "#1 } }
-    \tex_advance:D \l__str_internal_int \c_one
-    \__str_encode_eight_bit_load:nn
-  }
-\cs_new:Npn \__str_encode_eight_bit_char:n #1
-  {
-    \if_int_compare:w #1 > \c_max_register_int
-      \flag_raise:n { str_error }
-    \else:
-      \if_int_compare:w \tex_dimen:D #1 < \l__str_internal_int
-        \if_int_compare:w \tex_skip:D \tex_dimen:D #1 = #1 \exp_stop_f:
-          \tex_the:D \tex_toks:D \tex_dimen:D #1 \exp_stop_f:
-          \exp_after:wN \exp_after:wN \exp_after:wN \use_none:nn
-        \fi:
-      \fi:
-      \__str_encode_eight_bit_char_aux:n {#1}
-    \fi:
-  }
-\cs_new:Npn \__str_encode_eight_bit_char_aux:n #1
-  {
-    \if_int_compare:w #1 < \c_two_hundred_fifty_six
-      \__str_output_byte:n {#1}
-    \else:
-      \flag_raise:n { str_error }
-    \fi:
-  }
-\__msg_kernel_new:nnn { str } { unknown-esc }
-  { Escaping~scheme~'#1'~(filtered:~'#2')~unknown. }
-\__msg_kernel_new:nnn { str } { unknown-enc }
-  { Encoding~scheme~'#1'~(filtered:~'#2')~unknown. }
-\__msg_kernel_new:nnnn { str } { native-escaping }
-  { The~'native'~encoding~scheme~does~not~support~any~escaping. }
-  {
-    Since~native~strings~do~not~consist~in~bytes,~
-    none~of~the~escaping~methods~make~sense.~
-    The~specified~escaping,~'#1',~will be ignored.
-  }
-\__msg_kernel_new:nnn { str } { file-not-found }
-  { File~'l3str-#1.def'~not~found. }
-\pdftex_if_engine:F
-  {
-    \__msg_kernel_new:nnnn { str } { non-byte }
-      { String~invalid~in~escaping~'#1':~it~may~only~contain~bytes. }
-      {
-        Some~characters~in~the~string~you~asked~to~convert~are~not~
-        8-bit~characters.~Perhaps~the~string~is~a~'native'~Unicode~string?~
-        If~it~is,~try~using\\
-        \\
-        \iow_indent:n
-          {
-            \iow_char:N\\str_set_convert:Nnnn \\
-            \ \ <str~var>~\{~<string>~\}~\{~native~\}~\{~<target~encoding>~\}
-          }
-      }
-  }
-\__msg_kernel_new:nnnn { str } { decode-8-bit }
-  { Invalid~string~in~encoding~'#1'. }
-  {
-    LaTeX~came~across~a~byte~which~is~not~defined~to~represent~
-    any~character~in~the~encoding~'#1'.
-  }
-\__msg_kernel_new:nnnn { str } { encode-8-bit }
-  { Unicode~string~cannot~be~converted~to~encoding~'#1'. }
+\cs_new:Npn \str_substr:Nnn #1 { \__str_substr:nnn { \str_range:Nnn #1 } }
+\cs_new:Npn \str_substr:nnn #1 { \__str_substr:nnn { \str_range:nnn {#1} } }
+\cs_new:Npn \str_substr_ignore_spaces:nnn #1
+  { \__str_substr:nnn { \str_range_ignore_spaces:nnn {#1} } }
+\cs_new:Npn \__str_substr:nnn #1#2#3
   {
-    The~encoding~'#1'~only~contains~a~subset~of~all~Unicode~characters.~
-    LaTeX~was~asked~to~convert~a~string~to~that~encoding,~but~that~
-    string~contains~a~character~that~'#1'~does~not~support.
+    \tl_if_empty:nTF {#2}
+      { \tl_if_empty:nTF {#3} { #1 { 1} { -1 } } { #1 { 1} {#3} } }
+      { \tl_if_empty:nTF {#3} { #1 {#2} { -1 } } { #1 {#2} {#3} } }
   }
-\cs_new_eq:NN \str_length:N \str_count:N
-\cs_new_eq:NN \str_length:n \str_count:n
-\cs_new_eq:NN \str_length_ignore_spaces:n \str_count_ignore_spaces:n
+\cs_new_eq:NN \c_lbrace_str \c_left_brace_str
+\cs_new_eq:NN \c_rbrace_str \c_right_brace_str
 %% 
 %%
 %% End of file `l3str.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3tl-analysis.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3tl-analysis.sty
index 134eeed9815..8598a3df85c 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3tl-analysis.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3tl-analysis.sty
@@ -104,7 +104,7 @@
   \cs_new_protected:Npn \__tl_analysis_disable_loop:N #1
     {
       \tex_lccode:D \c_zero `#1 ~
-      \tl_to_lowercase:n { \tex_let:D ^^@ } \c_undefined:D
+      \tl_to_lowercase:n { \tex_let:D ^^@ } \tex_undefined:D
       \__tl_analysis_disable_loop:N
     }
 \group_end:
@@ -269,7 +269,7 @@
     {
       \cs_new:Npn \__tl_analysis_b_char:Nww #1
         {
-          \if_meaning:w #1 \c_undefined:D            ? \else:
+          \if_meaning:w #1 \tex_undefined:D          ? \else:
           \if_catcode:w #1 \c_catcode_other_token    C \else:
           \if_catcode:w #1 \c_catcode_letter_token   B \else:
           \if_catcode:w #1 \c_math_toggle_token      3 \else:
@@ -439,7 +439,7 @@
       { \str_count:n { #1 ~ ( #4 #2 #3 ) } }
       > { \l_iow_line_count_int - \c_three }
       {
-        \str_substr:nnn { #1 ~ ( #4 #2 #3 ) } \c_one
+        \str_range:nnn { #1 ~ ( #4 #2 #3 ) } \c_one
           {
             \l_iow_line_count_int - \c_three
             - \str_count:N \c__tl_analysis_show_etc_str
diff --git a/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty b/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty
index a16079a1428..a05256b4f44 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty
@@ -48,7 +48,7 @@
 %% -----------------------------------------------------------------------
 %%
 \RequirePackage{xparse}
-\GetIdInfo$Id: l3galley.dtx 4388 2012-12-20 22:15:35Z joseph $
+\GetIdInfo$Id: l3galley.dtx 4402 2013-01-08 08:59:44Z bruno $
   {L3 Experimental galley code}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
diff --git a/Master/texmf-dist/tex/latex/l3kernel/expl3.sty b/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
index 653499b0ca4..7108cae2f3e 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: expl3.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: expl3.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -60,8 +60,8 @@
   }
 \def\ExplFileName{expl3}
 \def\ExplFileDescription{L3 Experimental code bundle wrapper}
-\def\ExplFileDate{2012/12/21}
-\def\ExplFileVersion{4390}
+\def\ExplFileDate{2013/03/12}
+\def\ExplFileVersion{4467}
 \RequirePackage{etex}
 \relax
 \reserveinserts{32}
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3basics.sty b/Master/texmf-dist/tex/latex/l3kernel/l3basics.sty
index bc53602f68f..52e7a7f3735 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3basics.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3basics.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3basics.dtx Copyright (C) 1990-2012 The LaTeX3 project
+%% File: l3basics.dtx Copyright (C) 1990-2013 The LaTeX3 project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3basics.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3basics.dtx 4428 2013-01-10 13:23:29Z bruno $
   {L3 Basic definitions}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -562,7 +562,7 @@
 \cs_new_protected_nopar:Npn \cs_new_eq:Nc { \exp_args:NNc \cs_new_eq:NN }
 \cs_new_protected_nopar:Npn \cs_new_eq:cc { \exp_args:Ncc \cs_new_eq:NN }
 \cs_new_protected:Npn \cs_undefine:N #1
-  { \cs_gset_eq:NN #1 \c_undefined:D }
+  { \cs_gset_eq:NN #1 \tex_undefined:D }
 \cs_new_protected:Npn \cs_undefine:c #1
   {
     \if_cs_exist:w #1 \cs_end:
@@ -570,7 +570,7 @@
     \else:
       \exp_after:wN \use_none:n
     \fi:
-    { \cs_gset_eq:cN {#1} \c_undefined:D }
+    { \cs_gset_eq:cN {#1} \tex_undefined:D }
   }
 \cs_set_protected:Npn \__cs_parm_from_arg_count:nnF #1#2
   {
@@ -845,11 +845,6 @@
 \cs_new_eq:NN \__prg_break_point: \prg_do_nothing:
 \cs_new:Npn \__prg_break: #1 \__prg_break_point: { }
 \cs_new:Npn \__prg_break:n #1#2 \__prg_break_point: {#1}
-\cs_new_eq:NN \str_if_eq_p:xx \str_if_eq_x_p:nn
-\cs_new_eq:NN \str_if_eq:xxT  \str_if_eq_x:nnT
-\cs_new_eq:NN \str_if_eq:xxF  \str_if_eq_x:nnF
-\cs_new_eq:NN \str_if_eq:xxTF \str_if_eq_x:nnTF
-\cs_new_eq:NN \chk_if_free_cs:N \__chk_if_free_cs:N
 %% 
 %%
 %% End of file `l3basics.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty b/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty
index 263ab7bf875..89dd24ceae5 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3bootstrap.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3bootstrap.dtx Copyright (C) 2011-2012 The LaTeX3 project
+%% File: l3bootstrap.dtx Copyright (C) 2011-2013 The LaTeX3 project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -102,7 +102,7 @@
   {%
     \def\ExplFileDate{#1/#2/#3}%
   }
-\GetIdInfo$Id: l3bootstrap.dtx 3991 2012-07-16 19:00:35Z joseph $
+\GetIdInfo$Id: l3bootstrap.dtx 4420 2013-01-08 20:00:04Z joseph $
   {L3 Bootstrap code}
 \ProvidesPackage{l3bootstrap}
   [%
@@ -255,20 +255,6 @@
           }%
       }%
   }
-\protected\edef\ExplSyntaxNamesOn
-  {%
-    \expandafter\noexpand
-      \csname\detokenize{char_set_catcode_letter:n}\endcsname{58}%
-    \expandafter\noexpand
-      \csname\detokenize{char_set_catcode_letter:n}\endcsname{95}%
-  }
-\protected\edef\ExplSyntaxNamesOff
-  {%
-    \expandafter\noexpand
-      \csname\detokenize{char_set_catcode_other:n}\endcsname{58}%
-    \expandafter\noexpand
-      \csname\detokenize{char_set_catcode_math_subscript:n}\endcsname{95}%
-  }
 %% 
 %%
 %% End of file `l3bootstrap.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3box.sty b/Master/texmf-dist/tex/latex/l3kernel/l3box.sty
index 56016c45566..af3070bcaaa 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3box.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3box.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3box.dtx 4347 2012-12-08 09:11:29Z joseph $
+\GetIdInfo$Id: l3box.dtx 4411 2013-01-08 12:21:52Z bruno $
   {L3 Experimental boxes}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -81,14 +81,8 @@
   { \tex_global:D  \box_set_eq_clear:NN }
 \cs_generate_variant:Nn \box_set_eq_clear:NN  { c , Nc , cc }
 \cs_generate_variant:Nn \box_gset_eq_clear:NN { c , Nc , cc }
-\cs_new_eq:NN \box_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \box_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \box_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \box_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \box_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \box_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \box_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \box_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \box_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \box_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new_eq:NN \box_ht:N \tex_ht:D
 \cs_new_eq:NN \box_dp:N \tex_dp:D
 \cs_new_eq:NN \box_wd:N \tex_wd:D
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3candidates.sty b/Master/texmf-dist/tex/latex/l3kernel/l3candidates.sty
index 65919abf3ec..058849f5f60 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3candidates.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3candidates.sty
@@ -47,7 +47,7 @@
 %% -----------------------------------------------------------------------
 %%
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3candidates.dtx 4383 2012-12-20 15:10:48Z bruno $
+\GetIdInfo$Id: l3candidates.dtx 4466 2013-03-09 14:58:43Z joseph $
   {L3 Experimental additions to l3kernel}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -785,12 +785,14 @@
 \cs_new:Npn \prop_map_tokens:Nn #1#2
   {
     \exp_last_unbraced:Nno \__prop_map_tokens:nwn {#2} #1
-    \q_recursion_tail \q__prop { }
+    \s__prop \q_recursion_tail \s__prop { }
     \__prg_break_point:Nn \prop_map_break: { }
   }
-\cs_new:Npn \__prop_map_tokens:nwn #1 \q__prop #2 \q__prop #3
+\cs_new:Npn \__prop_map_tokens:nwn #1 \s__prop #2 \s__prop #3
   {
-    \__quark_if_recursion_tail_break:NN #2 \prop_map_break:
+    \if_meaning:w \q_recursion_tail #2
+      \exp_after:wN \prop_map_break:
+    \fi:
     \use:n {#1} {#2} {#3}
     \__prop_map_tokens:nwn {#1}
   }
@@ -1129,11 +1131,11 @@
             \exp_after:wN \__peek_false:w
           \fi:
         }
-      \cs_new_protected_nopar:Npn \__peek_N_type:w #1 OUTER #2 \q_mark #3
+      \cs_new_protected:Npn \__peek_N_type:w #1 OUTER #2 \q_mark #3
         { #3 {#1} {#2} }
     }
 \group_end:
-\cs_new_protected_nopar:Npn \__peek_N_type_aux:nnw #1 #2 #3 \fi:
+\cs_new_protected:Npn \__peek_N_type_aux:nnw #1 #2 #3 \fi:
   {
     \fi:
     \tl_if_in:noTF {#1} { \tl_to_str:n {ma} }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3clist.sty b/Master/texmf-dist/tex/latex/l3kernel/l3clist.sty
index 6edd2295361..c06c5498149 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3clist.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3clist.sty
@@ -15,7 +15,7 @@
 %% 
 %% File: l3clist.dtx Copyright (C) 2004-2011 Frank Mittelbach,
 %%                                 The LaTeX3 project
-%%                             (C) 2012 The LaTeX3 Project
+%%                             (C) 2012,2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -48,7 +48,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3clist.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3clist.dtx 4414 2013-01-08 12:32:12Z bruno $
   {L3 Comma separated lists}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -89,14 +89,8 @@
   }
 \cs_generate_variant:Nn \clist_concat:NNN  { ccc }
 \cs_generate_variant:Nn \clist_gconcat:NNN { ccc }
-\cs_new_eq:NN \clist_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \clist_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \clist_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \clist_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \clist_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \clist_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \clist_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \clist_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \clist_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \clist_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new:Npn \__clist_trim_spaces_generic:nw #1#2 ,
   {
     \__tl_trim_spaces:nn {#2}
@@ -432,15 +426,6 @@
 \clist_new:N \l_tmpb_clist
 \clist_new:N \g_tmpa_clist
 \clist_new:N \g_tmpb_clist
-\prg_new_eq_conditional:NNn \clist__if_eq:NN \tl_if_eq:NN { p , T , F , TF }
-\prg_new_eq_conditional:NNn \clist_if_eq:Nc \tl_if_eq:Nc { p , T , F , TF }
-\prg_new_eq_conditional:NNn \clist_if_eq:cN \tl_if_eq:cN { p , T , F , TF }
-\prg_new_eq_conditional:NNn \clist_if_eq:cc \tl_if_eq:cc { p , T , F , TF }
-\cs_new_eq:NN \clist_length:N \clist_count:N
-\cs_new_eq:NN \clist_length:n \clist_count:c
-\cs_new_eq:NN \clist_length:c \clist_count:n
-\cs_new_eq:NN \clist_use:N \tl_use:N
-\cs_new_eq:NN \clist_use:c \tl_use:c
 %% 
 %%
 %% End of file `l3clist.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls b/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
index 4aa57de4d9d..d3dd89238cb 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
@@ -4,8 +4,7 @@
 %%
 %% The original source files were:
 %%
-%% l3doc.dtx  (with options: `class,cfg')
-%% 
+%% l3doc.dtx  (with options: `class')
 %% 
 %% EXPERIMENTAL CODE
 %% 
@@ -14,7 +13,6 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% 
 %% File: l3doc.dtx Copyright (C) 1990-2012 The LaTeX3 project
 %%
 %% It may be distributed and/or modified under the conditions of the
@@ -52,7 +50,7 @@
 \let     \fileversionOld        \ExplFileVersion
 \let \filedescriptionOld        \ExplFileDescription
 \RequirePackage{expl3,xparse,calc}
-\GetIdInfo$Id: l3doc.dtx 4267 2012-11-04 19:42:13Z joseph $
+\GetIdInfo$Id: l3doc.dtx 4442 2013-01-13 08:56:27Z bruno $
           {L3 Experimental documentation class}
 \ProvidesExplClass
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -960,6 +958,7 @@
       {
         \seq_use:Nnnn \g__codedoc_tmpa_seq
           { \,~and~ } { \,,~ } { \,,~and~ }
+        \@.
       }
       { \seq_item:Nn \g__codedoc_tmpa_seq {1}\,~and~others. }
 
@@ -1458,51 +1457,6 @@
   \DisableCrossrefs
   \OnlyDescription
  }
-\tl_new:N \Team
-\tl_set:Nn \Team
- {
-  The~\LaTeX3~Project\thanks
-   {
-    Frank~Mittelbach,~Denys~Duchier,~Chris~Rowley,~
-    Rainer~Sch\"opf,~Johannes~Braams,~Michael~Downes,~
-    David~Carlisle,~Alan~Jeffrey,~Morten~H\o{}gholm,~Thomas~Lotze,~
-    Javier~Bezos,~Will~Robertson,~Joseph~Wright,~Bruno~Le~Floch
-   }
- }
-\NewDocumentCommand{\ExplMakeTitle}{mm}
- {
-  \title
-   {
-    The~\pkg{#1}~package \\ #2
-    \thanks
-     {
-      This~file~describes~v\ExplFileVersion,~
-      last~revised~\ExplFileDate.
-     }
-   }
-   \author
-    {
-     The~\LaTeX3~Project\thanks{E-mail:~
-     \href{mailto:latex-l@listserv.uni-heidelberg.de}
-          {latex-l@listserv.uni-heidelberg.de}}
-    }
-   \date{Released~\ExplFileDate}
-   \maketitle
- }
-\DeclareDocumentCommand\ie{}{\emph{i.e.}}
-\DeclareDocumentCommand\eg{}{\emph{e.g.}}
-\DeclareDocumentCommand\Ie{}{\emph{I.e.}}
-\DeclareDocumentCommand\Eg{}{\emph{E.g.}}
-\AtBeginDocument
- {
-  \clist_map_inline:nn
-   {
-    asin, acos, atan, acot,
-    asinh, acosh, atanh, acoth, round, floor, ceil
-   }
-   { \exp_args:Nc \DeclareMathOperator{#1}{#1} }
- }
-\NewDocumentCommand { \nan } { } { \text { \texttt { nan } } }
 %% 
 %%
 %% End of file `l3doc.cls'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty b/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty
index 6dceea954ad..efd3425ec59 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3expan.sty
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3expan.dtx 4149 2012-08-28 10:50:40Z bruno $
+\GetIdInfo$Id: l3expan.dtx 4458 2013-02-03 15:49:37Z bruno $
   {L3 Argument expansion}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3file.sty b/Master/texmf-dist/tex/latex/l3kernel/l3file.sty
index b1a119b7fd3..f86225c08d8 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3file.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3file.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3file.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3file.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3file.dtx 4377 2012-12-20 11:13:29Z bruno $
+\GetIdInfo$Id: l3file.dtx 4446 2013-01-14 00:03:17Z bruno $
   {L3 File and I/O operations}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -182,33 +182,12 @@
       { \seq_gput_right:No \g__file_record_seq { \tl_to_str:n {#1} } }
   }
 \cs_new_eq:NN \c_term_ior \c_sixteen
-\tl_const:Nn \c__ior_streams_tl
-  {
-    \c_zero
-    \c_one
-    \c_two
-    \c_three
-    \c_four
-    \c_five
-    \c_six
-    \c_seven
-    \c_eight
-    \c_nine
-    \c_ten
-    \c_eleven
-    \c_twelve
-    \c_thirteen
-    \c_fourteen
-    \c_fifteen
-  }
+\seq_new:N \g__ior_streams_seq
+\tl_new:N \l__ior_stream_tl
 \prop_new:N \g__ior_streams_prop
-\prop_put:Nnn \g__ior_streams_prop { 0 } { LaTeX2e~reserved }
-\int_new:N \l__ior_stream_int
-\cs_set_eq:NN \__ior_new:N \newread
-\cs_generate_variant:Nn \__ior_new:N { c }
+\prop_gput:Nnn \g__ior_streams_prop { 0 } { LaTeX2e~reserved }
 \cs_new_protected:Npn \ior_new:N #1 { \cs_new_eq:NN #1 \c_term_ior }
 \cs_generate_variant:Nn \ior_new:N { c }
-\ior_new:N \g__file_internal_ior
 \cs_new_protected:Npn \ior_open:Nn #1#2
   { \__file_name_sanitize:nn {#2} { \__ior_open_aux:Nn #1 } }
 \cs_generate_variant:Nn \ior_open:Nn { c }
@@ -220,7 +199,10 @@
       { \__ior_open:No #1 \l__file_internal_name_tl }
   }
 \prg_new_protected_conditional:Npnn \ior_open:Nn #1#2 { T , F , TF }
-  { \__file_name_sanitize:nn {#2} { \__ior_open_aux:NnTF #1 } }
+  { \__file_name_sanitize:nn {#2} { \__ior_open:NnTF #1 } }
+\cs_generate_variant:Nn \ior_open:NnT  { c }
+\cs_generate_variant:Nn \ior_open:NnF  { c }
+\cs_generate_variant:Nn \ior_open:NnTF { c }
 \cs_new_protected:Npn \__ior_open_aux:NnTF #1#2
   {
     \file_add_path:nN {#2} \l__file_internal_name_tl
@@ -231,71 +213,33 @@
         \prg_return_true:
       }
   }
-\cs_generate_variant:Nn \ior_open:NnT  { c }
-\cs_generate_variant:Nn \ior_open:NnF  { c }
-\cs_generate_variant:Nn \ior_open:NnTF { c }
 \cs_new_protected:Npn \__ior_open:Nn #1#2
   {
     \ior_close:N #1
-    \int_set_eq:NN \l__ior_stream_int \c_sixteen
-    \tl_map_function:NN \c__ior_streams_tl \__ior_alloc:n
-    \int_compare:nNnTF \l__ior_stream_int = \c_sixteen
-      { \__msg_kernel_fatal:nn { kernel } { input-streams-exhausted } }
+    \seq_gpop:NNTF \g__ior_streams_seq \l__ior_stream_tl
+      { \__ior_open_stream:Nn #1 {#2} }
       {
-        \__ior_alloc:N #1
-        \prop_gput:NVn \g__ior_streams_prop \l__ior_stream_int {#2}
-        \tex_openin:D #1#2 \scan_stop:
+        \newread #1
+        \tl_set:Nx \l__ior_stream_tl { \int_eval:n {#1} }
+        \__ior_open_stream:Nn #1 {#2}
       }
   }
 \cs_generate_variant:Nn \__ior_open:Nn { No }
-\cs_new_protected:Npn \__ior_alloc:n #1
+\cs_new_protected:Npn \__ior_open_stream:Nn #1#2
   {
-    \prop_if_in:NnF \g__ior_streams_prop {#1}
-      {
-        \int_set:Nn \l__ior_stream_int {#1}
-        \tl_map_break:
-      }
-  }
-\ior_new:N \g__ior_internal_ior
-\cs_new_protected:Npn \__ior_alloc:N #1
-  {
-    \cs_if_exist:cF { g_ior_ \int_use:N \l__ior_stream_int _ior }
-      {
-        \__ior_alloc:
-        \int_compare:nNnT \l__ior_stream_int = \c_sixteen
-          {
-            \__ior_new:N \g__ior_internal_ior
-            \int_set:Nn \l__ior_stream_int { \g__ior_internal_ior }
-            \cs_gset_eq:cN
-              { g_ior_ \int_use:N \l__ior_stream_int _ior } \g__ior_internal_ior
-          }
-      }
-    \cs_gset_eq:Nc #1 { g_ior_ \int_use:N \l__ior_stream_int _ior }
-  }
-\cs_new_protected_nopar:Npn \__ior_alloc:
-  {
-    \int_incr:N \l__ior_stream_int
-    \int_compare:nNnT \l__ior_stream_int < \c_sixteen
-      {
-        \cs_if_exist:cTF { g_ior_ \int_use:N \l__ior_stream_int _ior }
-          {
-            \prop_if_in:NVT \g__ior_streams_prop \l__ior_stream_int
-              { \__ior_alloc: }
-          }
-          { \__ior_alloc: }
-      }
+    \tex_global:D \tex_chardef:D #1 = \l__ior_stream_tl \scan_stop:
+    \prop_gput:NVn \g__ior_streams_prop #1 {#2}
+    \tex_openin:D #1 #2 \scan_stop:
   }
 \cs_new_protected:Npn \ior_close:N #1
   {
-    \__chk_if_exist_cs:N #1
-    \int_compare:nNnF #1 < \c_zero
+    \int_compare:nT { \c_minus_one < #1 < \c_sixteen }
       {
-        \int_compare:nNnF #1 > \c_fifteen
-          {
-            \tex_closein:D #1
-            \prop_gremove:NV \g__ior_streams_prop #1
-            \cs_gset_eq:NN #1 \c_term_ior
-          }
+        \tex_closein:D #1
+        \prop_gremove:NV \g__ior_streams_prop #1
+        \seq_if_in:NVF \g__ior_streams_seq #1
+          { \seq_gpush:NV \g__ior_streams_seq #1 }
+        \cs_gset_eq:NN #1 \c_term_ior
       }
   }
 \cs_generate_variant:Nn \ior_close:N { c }
@@ -337,16 +281,15 @@
         \int_set:Nn \tex_endlinechar:D { \int_use:N \tex_endlinechar:D }
       }
   }
+\ior_new:N \g__file_internal_ior
 \cs_new_eq:NN \c_log_iow  \c_minus_one
 \cs_new_eq:NN \c_term_iow \c_sixteen
-\cs_new_eq:NN \c__iow_streams_tl \c__ior_streams_tl
+\seq_new:N \g__iow_streams_seq
+\tl_new:N \l__iow_stream_tl
 \prop_new:N \g__iow_streams_prop
 \prop_put:Nnn \g__iow_streams_prop { 0 } { LaTeX2e~reserved }
 \prop_put:Nnn \g__iow_streams_prop { 1 } { LaTeX2e~reserved }
 \prop_put:Nnn \g__iow_streams_prop { 2 } { LaTeX2e~reserved }
-\cs_new_eq:NN \l__iow_stream_int \l__ior_stream_int
-\cs_set_eq:NN \__iow_new:N \newwrite
-\cs_generate_variant:Nn \__iow_new:N { c }
 \cs_new_protected:Npn \iow_new:N #1 { \cs_new_eq:NN #1 \c_term_iow }
 \cs_generate_variant:Nn \iow_new:N { c }
 \cs_new_protected:Npn \iow_open:Nn #1#2
@@ -355,64 +298,30 @@
 \cs_new_protected:Npn \__iow_open:Nn #1#2
   {
     \iow_close:N #1
-    \int_set_eq:NN \l__iow_stream_int \c_sixteen
-    \tl_map_function:NN \c__iow_streams_tl \__iow_alloc:n
-    \int_compare:nNnTF \l__iow_stream_int = \c_sixteen
-      { \__msg_kernel_fatal:nn { kernel } { output-streams-exhausted } }
-      {
-        \__iow_alloc:N #1
-        \prop_gput:NVn \g__iow_streams_prop \l__iow_stream_int {#2}
-        \tex_immediate:D \tex_openout:D #1#2 \scan_stop:
-      }
-  }
-\cs_new_protected:Npn \__iow_alloc:n #1
-  {
-    \prop_if_in:NnF \g__iow_streams_prop {#1}
-      {
-        \int_set:Nn \l__iow_stream_int {#1}
-        \tl_map_break:
-      }
-  }
-\iow_new:N \g__iow_internal_iow
-\cs_new_protected:Npn \__iow_alloc:N #1
-  {
-    \cs_if_exist:cF { g_iow_ \int_use:N \l__iow_stream_int _iow }
+    \seq_gpop:NNTF \g__iow_streams_seq \l__iow_stream_tl
+      { \__iow_open_stream:Nn #1 {#2} }
       {
-        \__iow_alloc:
-        \int_compare:nNnT \l__iow_stream_int = \c_sixteen
-          {
-            \__iow_new:N \g__iow_internal_iow
-            \int_set:Nn \l__iow_stream_int { \g__iow_internal_iow }
-            \cs_gset_eq:cN
-              { g_iow_ \int_use:N \l__iow_stream_int _iow } \g__iow_internal_iow
-          }
+        \newwrite #1
+        \tl_set:Nx \l__iow_stream_tl { \int_eval:n {#1} }
+        \__iow_open_stream:Nn #1 {#2}
       }
-    \cs_gset_eq:Nc #1 { g_iow_ \int_use:N \l__iow_stream_int _iow }
   }
-\cs_new_protected_nopar:Npn \__iow_alloc:
+\cs_generate_variant:Nn \__iow_open:Nn { No }
+\cs_new_protected:Npn \__iow_open_stream:Nn #1#2
   {
-    \int_incr:N \l__iow_stream_int
-    \int_compare:nNnT \l__iow_stream_int < \c_sixteen
-      {
-        \cs_if_exist:cTF { g_iow_ \int_use:N \l__iow_stream_int _iow }
-          {
-            \prop_if_in:NVT \g__iow_streams_prop \l__iow_stream_int
-              { \__iow_alloc: }
-          }
-          { \__iow_alloc: }
-      }
+    \tex_global:D \tex_chardef:D #1 = \l__iow_stream_tl \scan_stop:
+    \prop_gput:NVn \g__iow_streams_prop #1 {#2}
+    \tex_immediate:D \tex_openout:D #1 #2 \scan_stop:
   }
 \cs_new_protected:Npn \iow_close:N #1
   {
-    \__chk_if_exist_cs:N #1
-    \int_compare:nNnF #1 < \c_zero
+    \int_compare:nT { \c_minus_one < #1 < \c_sixteen }
       {
-        \int_compare:nNnF #1 > \c_fifteen
-          {
-            \tex_immediate:D \tex_closeout:D #1
-            \prop_gremove:NV \g__iow_streams_prop #1
-            \cs_gset_eq:NN #1 \c_term_iow
-          }
+        \tex_immediate:D \tex_closeout:D #1
+        \prop_gremove:NV \g__iow_streams_prop #1
+        \seq_if_in:NVF \g__iow_streams_seq #1
+          { \seq_gpush:NV \g__iow_streams_seq #1 }
+        \cs_gset_eq:NN #1 \c_term_ior
       }
   }
 \cs_generate_variant:Nn \iow_close:N { c }
@@ -634,9 +543,6 @@
     Spaces~are~not~permitted~in~files~loaded~by~LaTeX: \\
     Further~errors~may~follow!
   }
-\cs_new_protected:Npn \iow_wrap:xnnnN #1#2#3#4#5
-  { \iow_wrap:nnnN {#1} {#2} {#4} #5 }
-\cs_new_eq:NN \l_iow_line_length_int \l_iow_line_count_int
 \cs_new_eq:NN \ior_to:NN \ior_get:NN
 \cs_new_protected_nopar:Npn \ior_gto:NN { \tex_global:D \ior_to:NN }
 \cs_new_eq:NN \ior_str_to:NN \ior_get_str:NN
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3fp.sty b/Master/texmf-dist/tex/latex/l3kernel/l3fp.sty
index ec67d73f5d5..6bbe576f511 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3fp.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3fp.sty
@@ -59,7 +59,7 @@
 %% -----------------------------------------------------------------------
 %%
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3fp.dtx 4305 2012-11-10 08:40:25Z joseph $
+\GetIdInfo$Id: l3fp.dtx 4449 2013-01-19 23:55:05Z bruno $
   {L3 Floating points}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -400,7 +400,7 @@
 %% -----------------------------------------------------------------------
 %%
 \cs_new_protected:Npn \fp_flag_off:n #1
-  { \cs_set_eq:cN { l__fp_ #1 _flag_token } \c_undefined:D }
+  { \cs_set_eq:cN { l__fp_ #1 _flag_token } \tex_undefined:D }
 \cs_new:Npn \fp_flag_on:n #1
   { \exp_args:Nc \use_none:n { l__fp_ #1 _flag_token } }
 \prg_new_conditional:Npnn \fp_if_flag_on:n #1 { p , T , F , TF }
@@ -411,10 +411,10 @@
       \prg_return_false:
     \fi:
   }
-\cs_new_eq:NN \l__fp_invalid_operation_flag_token \c_undefined:D
-\cs_new_eq:NN \l__fp_division_by_zero_flag_token \c_undefined:D
-\cs_new_eq:NN \l__fp_overflow_flag_token \c_undefined:D
-\cs_new_eq:NN \l__fp_underflow_flag_token \c_undefined:D
+\cs_new_eq:NN \l__fp_invalid_operation_flag_token \tex_undefined:D
+\cs_new_eq:NN \l__fp_division_by_zero_flag_token \tex_undefined:D
+\cs_new_eq:NN \l__fp_overflow_flag_token \tex_undefined:D
+\cs_new_eq:NN \l__fp_underflow_flag_token \tex_undefined:D
 \cs_new_protected:Npn \fp_trap:nn #1#2
   {
     \cs_if_exist_use:cF { __fp_trap_#1_set_#2: }
@@ -1917,14 +1917,8 @@
 %%
 %% -----------------------------------------------------------------------
 %%
-\cs_new_eq:NN \fp_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \fp_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \fp_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \fp_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \fp_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \fp_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \fp_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \fp_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \fp_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \fp_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \prg_new_conditional:Npnn \fp_compare:n #1 { p , T , F , TF }
   {
     \exp_after:wN \__fp_compare_return:w
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3int.sty b/Master/texmf-dist/tex/latex/l3kernel/l3int.sty
index cd2ab964888..b104958c41f 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3int.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3int.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3int.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3int.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3int.dtx 4237 2012-09-26 10:18:58Z bruno $
+\GetIdInfo$Id: l3int.dtx 4444 2013-01-13 20:27:20Z bruno $
   {L3 Integers}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -173,14 +173,8 @@
 \cs_new_protected:Npn \int_gset_eq:NN #1#2 { \tex_global:D #1 = #2 }
 \cs_generate_variant:Nn \int_gset_eq:NN {       c }
 \cs_generate_variant:Nn \int_gset_eq:NN { Nc , cc }
-\cs_new_eq:NN \int_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \int_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \int_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \int_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \int_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \int_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \int_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \int_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \int_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \int_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new_protected:Npn \int_add:Nn #1#2
   { \tex_advance:D #1 by \__int_eval:w #2 \__int_eval_end: }
 \cs_new_protected:Npn \int_sub:Nn #1#2
@@ -219,46 +213,62 @@
     \__prg_compare_error:
   }
 \cs_new:Npn \__prg_compare_error:Nw
-    #1#2 \prg_return_true: \else: \prg_return_false: \fi:
+    #1#2 \q_stop
   {
+    { }
+    \c_zero \fi:
     \__msg_kernel_expandable_error:nnn
       { kernel } { unknown-comparison } {#1}
     \prg_return_false:
   }
 \prg_new_conditional:Npnn \int_compare:n #1 { p , T , F , TF }
   {
-    \exp_after:wN \__int_compare_aux:Nw \int_use:N \__int_eval:w #1
-        \__prg_compare_error: \__int_eval_end:
-      \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
+    \exp_after:wN \__int_compare:w
+    \int_use:N \__int_eval:w #1 \__prg_compare_error:
+  }
+\cs_new:Npn \__int_compare:w #1 \__prg_compare_error:
+  {
+    \exp_after:wN \if_false: \__int_value:w
+      \__int_compare:Nw #1 e { = nd_ } \q_stop
   }
-\cs_new:Npn \__int_compare_aux:Nw #1#2 \__prg_compare_error:
+\cs_new:Npn \__int_compare:Nw #1#2 \q_stop
   {
-    \exp_after:wN \__int_compare_aux:NNw
-      \__int_to_roman:w - 0 #2 ?? \q_mark
-    #1#2
+    \exp_after:wN \__int_compare:NNw
+      \__int_to_roman:w - 0 #2 \q_mark
+    #1#2 \q_stop
   }
-\cs_new:Npn \__int_compare_aux:NNw #1#2#3 \q_mark
+\cs_new:Npn \__int_compare:NNw #1#2#3 \q_mark
   {
+    \etex_unexpanded:D
     \use:c { __int_compare_  #1  \if_meaning:w = #2 =  \fi: :NNw }
       \__prg_compare_error:Nw #1
   }
+\cs_new:cpn { __int_compare_end_=:NNw } #1#2#3 e #4 \q_stop
+  {
+    {#3} \exp_stop_f:
+    \prg_return_false: \else: \prg_return_true: \fi:
+  }
+\cs_new:Npn \__int_compare:nnN #1#2#3
+  {
+        {#2} \exp_stop_f:
+      \prg_return_false: \exp_after:wN \use_none_delimit_by_q_stop:w
+    \fi:
+    #1 #2 #3 \exp_after:wN \__int_compare:Nw \__int_value:w \__int_eval:w
+  }
 \cs_new:cpn { __int_compare_=:NNw } #1#2#3 =
-  { \if_int_compare:w #3 = \__int_eval:w }
+  { \__int_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} = }
 \cs_new:cpn { __int_compare_<:NNw } #1#2#3 <
-  { \if_int_compare:w #3 < \__int_eval:w }
+  { \__int_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} < }
 \cs_new:cpn { __int_compare_>:NNw } #1#2#3 >
-  { \if_int_compare:w #3 > \__int_eval:w }
+  { \__int_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} > }
 \cs_new:cpn { __int_compare_==:NNw } #1#2#3 ==
-  { \if_int_compare:w #3 = \__int_eval:w }
+  { \__int_compare:nnN { \reverse_if:N \if_int_compare:w } {#3} = }
 \cs_new:cpn { __int_compare_!=:NNw } #1#2#3 !=
-  { \reverse_if:N \if_int_compare:w #3 = \__int_eval:w }
+  { \__int_compare:nnN { \if_int_compare:w } {#3} = }
 \cs_new:cpn { __int_compare_<=:NNw } #1#2#3 <=
-  { \reverse_if:N \if_int_compare:w #3 > \__int_eval:w }
+  { \__int_compare:nnN { \if_int_compare:w } {#3} > }
 \cs_new:cpn { __int_compare_>=:NNw } #1#2#3 >=
-  { \reverse_if:N \if_int_compare:w #3 < \__int_eval:w }
+  { \__int_compare:nnN { \if_int_compare:w } {#3} < }
 \prg_new_conditional:Npnn \int_compare:nNn #1#2#3 { p , T , F , TF }
   {
     \if_int_compare:w \__int_eval:w #1 #2 \__int_eval:w #3 \__int_eval_end:
@@ -767,11 +777,6 @@
 \int_new:N \l_tmpb_int
 \int_new:N \g_tmpa_int
 \int_new:N \g_tmpb_int
-\cs_new_eq:NN \if_num:w \if_int_compare:w
-\int_new:N \l_tmpc_int
-\cs_new_eq:NN \int_eval:w    \__int_eval:w
-\cs_new_eq:NN \int_eval_end: \__int_eval_end:
-\cs_new_eq:NN \int_value:w \__int_value:w
 %% 
 %%
 %% End of file `l3int.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3keys.sty b/Master/texmf-dist/tex/latex/l3kernel/l3keys.sty
index fd2cac0632c..e232f8e1645 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3keys.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3keys.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3keys.dtx Copyright (C) 2006-2012 The LaTeX3 Project
+%% File: l3keys.dtx Copyright (C) 2006-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3keys.dtx 4256 2012-11-02 08:47:41Z joseph $
+\GetIdInfo$Id: l3keys.dtx 4461 2013-02-24 18:55:17Z joseph $
   {L3 Experimental key-value interfaces}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -110,8 +110,7 @@
   { \tl_if_head_eq_meaning:nNTF {#3} \q_no_value }
 \cs_new_protected:Npn \__keyval_split_key:n #1
   {
-    \str_if_eq_x:nnTF
-      { \exp_not:N \q_nil } { \exp_not:o { \use_none:nnn #1 \q_nil \q_nil } }
+    \quark_if_nil:oTF { \use_none:nnn #1 \q_nil \q_nil }
       { \tl_set:Nx \l__keyval_key_tl { \exp_not:o { \use_ii:nnn #1 \q_nil } } }
       { \__keyval_split_key:w #1 \q_stop }
   }
@@ -699,7 +698,6 @@
     The~key~'#1'~must~have~a~value.\\
     No~value~was~present:~the~key~will~be~ignored.
   }
-\cs_new_eq:NN \c_keys_code_root_tl \c__keys_code_root_tl
 %% 
 %%
 %% End of file `l3keys.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty b/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty
index 584b54ac427..5ceb1e0e81c 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3msg.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3msg.dtx Copyright (C) 2009-2012 The LaTeX3 Project
+%% File: l3msg.dtx Copyright (C) 2009-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3msg.dtx 4212 2012-09-09 12:24:04Z bruno $
+\GetIdInfo$Id: l3msg.dtx 4412 2013-01-08 12:23:19Z joseph $
   {L3 Messages}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -776,29 +776,6 @@
     \\ > \ \ \tl_to_str:n {#1}
     \ \ => \ \ \tl_to_str:n {#2}
   }
-\cs_new_nopar:Npn \msg_newline: { ^^J }
-\cs_new_nopar:Npn \msg_two_newlines: { ^^J ^^J }
-\cs_generate_variant:Nn \msg_log:n { x }
-\cs_generate_variant:Nn \msg_term:n { x }
-\cs_generate_variant:Nn \msg_interrupt:nnn { xxx }
-\cs_new_protected:Npn \msg_class_set:nn #1#2
-  {
-    \cs_if_exist:cTF { __msg_ #1 _code:nnnnnn }
-      \cs_set_protected:cpn
-      \cs_new_protected:cpn
-        { __msg_ #1 _code:nnnnnn } ##1##2##3##4##5##6 {#2}
-    \prop_clear_new:c { l__msg_redirect_ #1 _prop }
-    \cs_set_protected_nopar:cpn { msg_ #1 :nnxxxx }
-      { \__msg_use:nnnnnnn {#1} }
-    \cs_set_protected:cpx { msg_ #1 :nnxxx } ##1##2##3##4##5
-      { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} {##3} {##4} {##5} { } }
-    \cs_set_protected:cpx { msg_ #1 :nnxx } ##1##2##3##4
-      { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} {##3} {##4} { } { } }
-    \cs_set_protected:cpx { msg_ #1 :nnx } ##1##2##3
-      { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} {##3} { } { } { } }
-    \cs_set_protected:cpx { msg_ #1 :nn } ##1##2
-      { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} { } { } { } { } }
-  }
 %% 
 %%
 %% End of file `l3msg.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty b/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty
index 4a544ab6720..957a8300b4c 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3prg.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3prg.dtx Copyright (C) 2005-2012 The LaTeX3 Project
+%% File: l3prg.dtx Copyright (C) 2005-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3prg.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3prg.dtx 4459 2013-02-13 09:21:15Z will $
   {L3 Control structures}
 %%
 \ProvidesExplPackage
@@ -114,14 +114,8 @@
 \bool_new:N \l_tmpb_bool
 \bool_new:N \g_tmpa_bool
 \bool_new:N \g_tmpb_bool
-\cs_new_eq:NN \bool_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \bool_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \bool_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \bool_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \bool_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \bool_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \bool_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \bool_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \bool_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \bool_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \prg_new_conditional:Npnn \bool_if:n #1 { T , F , TF }
   {
     \if_predicate:w \bool_if_p:n {#1}
@@ -339,15 +333,6 @@
       }
   }
 \int_new:N \g__prg_map_int
-\cs_new_eq:NN \prg_case_int:nnn \int_case:nnn
-\cs_new_eq:NN \prg_case_str:nnn \str_case:nnn
-\cs_new_eq:NN \prg_case_str:onn \str_case:onn
-\cs_new_eq:NN \prg_case_str:xxn \str_case_x:nnn
-\cs_new_eq:NN \prg_case_tl:Nnn  \tl_case:Nnn
-\cs_new_eq:NN \prg_case_tl:cnn  \tl_case:cnn
-\cs_new_eq:NN \prg_stepwise_function:nnnN  \int_step_function:nnnN
-\cs_new_eq:NN \prg_stepwise_inline:nnnn    \int_step_inline:nnnn
-\cs_new_eq:NN \prg_stepwise_variable:nnnNn \int_step_variable:nnnNn
 %% 
 %%
 %% End of file `l3prg.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3prop.sty b/Master/texmf-dist/tex/latex/l3kernel/l3prop.sty
index 916ff713332..85cff451ddb 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3prop.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3prop.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3prop.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3prop.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,25 +46,24 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3prop.dtx 4212 2012-09-09 12:24:04Z bruno $
+\GetIdInfo$Id: l3prop.dtx 4423 2013-01-09 00:05:30Z bruno $
   {L3 Property lists}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
 \__expl_package_check:
-\quark_new:N \q__prop
-\tl_const:Nn \c_empty_prop { \q__prop }
-\cs_new_protected:Npn \prop_new:N #1 { \cs_new_eq:NN  #1  \c_empty_prop }
-\cs_new_protected:Npn \prop_new:c #1 { \cs_new_eq:cN {#1} \c_empty_prop }
-\cs_new_protected:Npn \prop_clear:N #1  { \cs_set_eq:NN   #1  \c_empty_prop }
-\cs_generate_variant:Nn \prop_clear:N { c }
-\cs_new_protected:Npn \prop_gclear:N #1 { \cs_gset_eq:NN  #1  \c_empty_prop }
-\cs_generate_variant:Nn \prop_gclear:N { c }
-\cs_new_protected:Npn \prop_clear_new:N #1
-  { \prop_if_exist:NTF #1 { \prop_clear:N #1 } { \prop_new:N #1 } }
-\cs_generate_variant:Nn \prop_clear_new:N { c }
-\cs_new_protected:Npn \prop_gclear_new:N #1
-  { \prop_if_exist:NTF #1 { \prop_gclear:N #1 } { \prop_new:N #1 } }
-\cs_generate_variant:Nn \prop_gclear_new:N { c }
+\__scan_new:N \s__prop
+\tl_new:N \l__prop_internal_tl
+\cs_new_eq:NN \c_empty_prop \c_empty_tl
+\cs_new_eq:NN \prop_new:N \tl_new:N
+\cs_new_eq:NN \prop_new:c \tl_new:c
+\cs_new_eq:NN \prop_clear:N  \tl_clear:N
+\cs_new_eq:NN \prop_clear:c  \tl_clear:c
+\cs_new_eq:NN \prop_gclear:N \tl_gclear:N
+\cs_new_eq:NN \prop_gclear:c \tl_gclear:c
+\cs_new_eq:NN \prop_clear_new:N  \tl_clear_new:N
+\cs_new_eq:NN \prop_clear_new:c  \tl_clear_new:c
+\cs_new_eq:NN \prop_gclear_new:N \tl_gclear_new:N
+\cs_new_eq:NN \prop_gclear_new:c \tl_gclear_new:c
 \cs_new_eq:NN \prop_set_eq:NN  \tl_set_eq:NN
 \cs_new_eq:NN \prop_set_eq:Nc  \tl_set_eq:Nc
 \cs_new_eq:NN \prop_set_eq:cN  \tl_set_eq:cN
@@ -79,22 +78,27 @@
 \prop_new:N \g_tmpb_prop
 \cs_new_protected:Npn \__prop_split:NnTF #1#2
   { \exp_args:NNo \__prop_split_aux:NnTF #1 { \tl_to_str:n {#2} } }
-\cs_new_protected:Npn \__prop_split_aux:NnTF #1#2
+\cs_new_protected:Npn \__prop_split_aux:NnTF #1#2#3#4
   {
-    \cs_set_protected:Npn \__prop_split_aux:w
-      ##1 \q__prop #2 \q__prop ##2 ##3 ##4 \q_mark ##5 \q_stop
-      { \__prop_split_aux:nnnn ##3 { {##1 \q__prop } {##2} {##4} } }
-    \exp_after:wN \__prop_split_aux:w #1 \q_mark
-         \q__prop #2 \q__prop { } { ? \use_ii:nn { } } \q_mark \q_stop
+    \cs_set:Npn \__prop_split_aux:w ##1
+      \s__prop #2 \s__prop ##2 ##3 \q_mark ##4 ##5 \q_stop
+      { ##4 {#3} {#4} }
+    \exp_after:wN \__prop_split_aux:w #1 \q_mark \use_i:nn
+      \s__prop #2 \s__prop { } \q_mark \use_ii:nn \q_stop
   }
-\cs_new:Npn \__prop_split_aux:nnnn #1#2#3#4 { #3 #2 }
-\cs_new_protected:Npn \__prop_split_aux:w { }
+\cs_new:Npn \__prop_split_aux:w { }
 \cs_new_protected:Npn \prop_remove:Nn #1#2
-  { \__prop_split:NnTF #1 {#2} { \__prop_remove:NNnnn \tl_set:Nn #1 } { } }
+  {
+    \__prop_split:NnTF #1 {#2}
+      { \tl_set:Nn #1 { ##1 ##3 } }
+      { }
+  }
 \cs_new_protected:Npn \prop_gremove:Nn #1#2
-  { \__prop_split:NnTF #1 {#2} { \__prop_remove:NNnnn \tl_gset:Nn #1 } { } }
-\cs_new_protected:Npn \__prop_remove:NNnnn #1#2#3#4#5
-  { #1 #2 { #3 #5 } }
+  {
+    \__prop_split:NnTF #1 {#2}
+      { \tl_gset:Nn #1 { ##1 ##3 } }
+      { }
+  }
 \cs_generate_variant:Nn \prop_remove:Nn  {     NV }
 \cs_generate_variant:Nn \prop_remove:Nn  { c , cV }
 \cs_generate_variant:Nn \prop_gremove:Nn {     NV }
@@ -102,30 +106,29 @@
 \cs_new_protected:Npn \prop_get:NnN #1#2#3
   {
     \__prop_split:NnTF #1 {#2}
-      { \__prop_get:Nnnn #3 }
+      { \tl_set:Nn #3 {##2} }
       { \tl_set:Nn #3 { \q_no_value } }
   }
-\cs_new_protected:Npn \__prop_get:Nnnn #1#2#3#4
-  { \tl_set:Nn #1 {#3} }
 \cs_generate_variant:Nn \prop_get:NnN {     NV , No }
 \cs_generate_variant:Nn \prop_get:NnN { c , cV , co }
 \cs_new_protected:Npn \prop_pop:NnN #1#2#3
   {
     \__prop_split:NnTF #1 {#2}
-      { \__prop_pop:NNNnnn \tl_set:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_set:Nn #1 { ##1 ##3 }
+      }
       { \tl_set:Nn #3 { \q_no_value } }
   }
 \cs_new_protected:Npn \prop_gpop:NnN #1#2#3
   {
     \__prop_split:NnTF #1 {#2}
-      { \__prop_pop:NNNnnn \tl_gset:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_gset:Nn #1 { ##1 ##3 }
+      }
       { \tl_set:Nn #3 { \q_no_value } }
   }
-\cs_new_protected:Npn \__prop_pop:NNNnnn #1#2#3#4#5#6
-  {
-    \tl_set:Nn #3 {#5}
-    #1 #2 { #4 #6 }
-  }
 \cs_generate_variant:Nn \prop_pop:NnN  {     No }
 \cs_generate_variant:Nn \prop_pop:NnN  { c , co }
 \cs_generate_variant:Nn \prop_gpop:NnN {     No }
@@ -133,45 +136,40 @@
 \prg_new_protected_conditional:Npnn \prop_pop:NnN #1#2#3 { T , F , TF }
   {
     \__prop_split:NnTF #1 {#2}
-      { \__prop_pop_true:NNNnnn \tl_set:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_set:Nn #1 { ##1 ##3 }
+        \prg_return_true:
+      }
       { \prg_return_false: }
   }
 \prg_new_protected_conditional:Npnn \prop_gpop:NnN #1#2#3 { T , F , TF }
   {
     \__prop_split:NnTF #1 {#2}
-      { \__prop_pop_true:NNNnnn \tl_gset:Nn #1 #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \tl_gset:Nn #1 { ##1 ##3 }
+        \prg_return_true:
+      }
       { \prg_return_false: }
   }
-\cs_new_protected:Npn \__prop_pop_true:NNNnnn #1#2#3#4#5#6
-  {
-    \tl_set:Nn #3 {#5}
-    #1 #2 { #4 #6 }
-    \prg_return_true:
-  }
 \cs_generate_variant:Nn \prop_pop:NnNT   { c }
 \cs_generate_variant:Nn \prop_pop:NnNF   { c }
 \cs_generate_variant:Nn \prop_pop:NnNTF  { c }
 \cs_generate_variant:Nn \prop_gpop:NnNT  { c }
 \cs_generate_variant:Nn \prop_gpop:NnNF  { c }
 \cs_generate_variant:Nn \prop_gpop:NnNTF { c }
-\cs_new_protected:Npn \prop_put:Nnn
+\cs_new_protected_nopar:Npn \prop_put:Nnn
   { \__prop_put:NNNnn \tl_set:Nx \tl_put_right:Nx }
-\cs_new_protected:Npn \prop_gput:Nnn
+\cs_new_protected_nopar:Npn \prop_gput:Nnn
   { \__prop_put:NNNnn \tl_gset:Nx \tl_gput_right:Nx }
 \cs_new_protected:Npn \__prop_put:NNNnn #1#2#3#4#5
   {
+    \tl_set:Nn \l__prop_internal_tl
+      { \s__prop \tl_to_str:n {#4} \s__prop { \exp_not:n {#5} } }
     \__prop_split:NnTF #3 {#4}
-      { \__prop_put:NNnnnnn #1 #3 {#4} {#5} }
-      { #2 #3 { \tl_to_str:n {#4} \exp_not:n { \q__prop {#5} \q__prop } } }
-  }
-\cs_new_protected:Npn \__prop_put:NNnnnnn #1#2#3#4#5#6#7
-  {
-    #1 #2
-      {
-        \exp_not:n {#5}
-        \tl_to_str:n {#3} \exp_not:n { \q__prop {#4} \q__prop }
-        \exp_not:n {#7}
-      }
+      { #1 #3 { \exp_not:n {##1} \l__prop_internal_tl \exp_not:n {##3} } }
+      { #2 #3 { \l__prop_internal_tl } }
   }
 \cs_generate_variant:Nn \prop_put:Nnn
   {     NnV , Nno , Nnx , NV , NVV , No , Noo }
@@ -187,44 +185,29 @@
   { \__prop_put_if_new:NNnn \tl_gput_right:Nx }
 \cs_new_protected:Npn \__prop_put_if_new:NNnn #1#2#3#4
   {
+    \tl_set:Nn \l__prop_internal_tl
+      { \s__prop \tl_to_str:n {#3} \s__prop \exp_not:n { {#4} } }
     \__prop_split:NnTF #2 {#3}
-      { \use_none:nnn }
-      {
-        #1 #2
-          { \tl_to_str:n {#3} \exp_not:n { \q__prop {#4} \q__prop } }
-      }
+      { }
+      { #1 #2 { \l__prop_internal_tl } }
   }
 \cs_generate_variant:Nn \prop_put_if_new:Nnn  { c }
 \cs_generate_variant:Nn \prop_gput_if_new:Nnn { c }
-\cs_new_eq:NN \prop_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \prop_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \prop_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \prop_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \prop_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \prop_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \prop_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \prop_if_exist_p:c \cs_if_exist_p:c
-\prg_new_conditional:Npnn \prop_if_empty:N #1 { p, T , F , TF }
-  {
-    \if_meaning:w #1 \c_empty_prop
-      \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
-  }
-\cs_generate_variant:Nn \prop_if_empty_p:N {c}
-\cs_generate_variant:Nn \prop_if_empty:NTF {c}
-\cs_generate_variant:Nn \prop_if_empty:NT  {c}
-\cs_generate_variant:Nn \prop_if_empty:NF  {c}
+\prg_new_eq_conditional:NNn \prop_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \prop_if_exist:c \cs_if_exist:c { TF , T , F , p }
+\prg_new_eq_conditional:NNn \prop_if_empty:N \tl_if_empty:N
+  { p , T , F , TF }
+\prg_new_eq_conditional:NNn \prop_if_empty:c \tl_if_empty:c
+  { p , T , F , TF }
 \prg_new_conditional:Npnn \prop_if_in:Nn #1#2 { p , T , F , TF }
   {
     \exp_last_unbraced:Noo \__prop_if_in:nwn
       { \tl_to_str:n {#2} } #1
-      \tl_to_str:n {#2} \q__prop { }
-    \q_recursion_tail % could be any cs != \q__prop
+      \s__prop \tl_to_str:n {#2} \s__prop { }
+    \q_recursion_tail
     \__prg_break_point:
   }
-\cs_new:Npn \__prop_if_in:nwn #1 \q__prop #2 \q__prop #3
+\cs_new:Npn \__prop_if_in:nwn #1 \s__prop #2 \s__prop #3
   {
     \str_if_eq_x:nnTF {#1} {#2}
       { \__prop_if_in:N }
@@ -232,7 +215,7 @@
   }
 \cs_new:Npn \__prop_if_in:N #1
   {
-    \if_meaning:w \q__prop #1
+    \if_meaning:w \s__prop #1
       \prg_return_true:
     \else:
       \prg_return_false:
@@ -250,14 +233,12 @@
 \prg_new_protected_conditional:Npnn \prop_get:NnN #1#2#3 { T , F , TF }
   {
     \__prop_split:NnTF #1 {#2}
-      { \__prop_get_true:Nnnn #3 }
+      {
+        \tl_set:Nn #3 {##2}
+        \prg_return_true:
+      }
       { \prg_return_false: }
   }
-\cs_new_protected:Npn \__prop_get_true:Nnnn #1#2#3#4
-  {
-    \tl_set:Nn #1 {#3}
-    \prg_return_true:
-  }
 \cs_generate_variant:Nn \prop_get:NnNT  {     NV , No }
 \cs_generate_variant:Nn \prop_get:NnNF  {     NV , No }
 \cs_generate_variant:Nn \prop_get:NnNTF {     NV , No }
@@ -267,12 +248,14 @@
 \cs_new:Npn \prop_map_function:NN #1#2
   {
     \exp_last_unbraced:NNo \__prop_map_function:Nwn #2
-      #1 \q_recursion_tail \q__prop { }
+      #1 \s__prop \q_recursion_tail \s__prop { }
     \__prg_break_point:Nn \prop_map_break: { }
   }
-\cs_new:Npn \__prop_map_function:Nwn #1 \q__prop #2 \q__prop #3
+\cs_new:Npn \__prop_map_function:Nwn #1 \s__prop #2 \s__prop #3
   {
-    \__quark_if_recursion_tail_break:nN {#2} \prop_map_break:
+    \if_meaning:w \q_recursion_tail #2
+      \exp_after:wN \prop_map_break:
+    \fi:
     #1 {#2} {#3}
     \__prop_map_function:Nwn #1
   }
@@ -285,7 +268,7 @@
     \exp_last_unbraced:Nco \__prop_map_function:Nwn
       { __prg_map_ \int_use:N \g__prg_map_int :w }
       #1
-      \q_recursion_tail \q__prop { }
+      \s__prop \q_recursion_tail \s__prop { }
     \__prg_break_point:Nn \prop_map_break: { \int_gdecr:N \g__prg_map_int }
   }
 \cs_generate_variant:Nn \prop_map_inline:Nn { c }
@@ -299,14 +282,6 @@
       { \prop_map_function:NN #1 \__msg_show_item:nn }
   }
 \cs_generate_variant:Nn \prop_show:N { c }
-\cs_new_eq:NN \prop_del:Nn \prop_remove:Nn
-\cs_new_eq:NN \prop_del:NV \prop_remove:NV
-\cs_new_eq:NN \prop_del:cn \prop_remove:cn
-\cs_new_eq:NN \prop_del:cV \prop_remove:cV
-\cs_new_eq:NN \prop_gdel:Nn \prop_gremove:Nn
-\cs_new_eq:NN \prop_gdel:NV \prop_gremove:NV
-\cs_new_eq:NN \prop_gdel:cn \prop_gremove:cn
-\cs_new_eq:NN \prop_gdel:cV \prop_gremove:cV
 %% 
 %%
 %% End of file `l3prop.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty b/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty
index 55cb5f18fb0..b80717c08ec 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3seq.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3seq.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3seq.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3seq.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3seq.dtx 4434 2013-01-12 09:33:40Z bruno $
   {L3 Sequences and stacks}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -111,20 +111,12 @@
   { \__seq_wrap_item:n {#1} }
 \cs_generate_variant:Nn \seq_set_split:Nnn  { NnV }
 \cs_generate_variant:Nn \seq_gset_split:Nnn { NnV }
-\cs_new_protected:Npn \seq_concat:NNN #1#2#3
-  { \tl_set:Nx #1 { \exp_not:o {#2} \exp_not:o {#3} } }
-\cs_new_protected:Npn \seq_gconcat:NNN #1#2#3
-  { \tl_gset:Nx #1 { \exp_not:o {#2} \exp_not:o {#3} } }
-\cs_generate_variant:Nn \seq_concat:NNN  { ccc }
-\cs_generate_variant:Nn \seq_gconcat:NNN { ccc }
-\cs_new_eq:NN \seq_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \seq_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \seq_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \seq_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \seq_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \seq_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \seq_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \seq_if_exist_p:c \cs_if_exist_p:c
+\cs_new_eq:NN \seq_concat:NNN  \tl_concat:NNN
+\cs_new_eq:NN \seq_gconcat:NNN \tl_gconcat:NNN
+\cs_new_eq:NN \seq_concat:ccc  \tl_concat:ccc
+\cs_new_eq:NN \seq_gconcat:ccc \tl_gconcat:ccc
+\prg_new_eq_conditional:NNn \seq_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \seq_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new_protected:Npn \seq_put_left:Nn #1#2
   { \tl_put_left:Nn #1 { \__seq_item:n {#2} } }
 \cs_new_protected:Npn \seq_put_right:Nn #1#2
@@ -441,10 +433,6 @@
 \seq_new:N \l_tmpb_seq
 \seq_new:N \g_tmpa_seq
 \seq_new:N \g_tmpb_seq
-\cs_new_eq:NN \seq_length:N \seq_count:N
-\cs_new_eq:NN \seq_length:c \seq_count:c
-\cs_new:Npn \seq_use:N #1 { \seq_map_function:NN #1 \use:n }
-\cs_generate_variant:Nn \seq_use:N { c }
 %% 
 %%
 %% End of file `l3seq.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3skip.sty b/Master/texmf-dist/tex/latex/l3kernel/l3skip.sty
index c9e6836ca2b..20f3c09ebcd 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3skip.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3skip.sty
@@ -14,7 +14,7 @@
 %% Do not distribute a modified version of this file.
 %% 
 %% File: l3skip.dtx Copyright (C) 2004-2011 Frank Mittelbach, The LaTeX3 Project
-%%                            (C) 2012 The LaTeX3 Project
+%%                            (C) 2012,2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -47,7 +47,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3skip.dtx 4260 2012-11-04 17:20:25Z joseph $
+\GetIdInfo$Id: l3skip.dtx 4444 2013-01-13 20:27:20Z bruno $
   {L3 Dimensions and skips}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -77,14 +77,8 @@
   { \dim_if_exist:NTF #1 { \dim_gzero:N #1 } { \dim_new:N #1 } }
 \cs_generate_variant:Nn \dim_zero_new:N  { c }
 \cs_generate_variant:Nn \dim_gzero_new:N { c }
-\cs_new_eq:NN \dim_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \dim_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \dim_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \dim_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \dim_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \dim_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \dim_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \dim_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \dim_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \dim_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new_protected:Npn \dim_set:Nn #1#2
   { #1 ~ \__dim_eval:w #2 \__dim_eval_end: }
 \cs_new_protected:Npn \dim_gset:Nn { \tex_global:D \dim_set:Nn }
@@ -148,40 +142,40 @@
   }
 \prg_new_conditional:Npnn \dim_compare:n #1 { p , T , F , TF }
   {
-    \exp_after:wN \__dim_compare_aux:w \dim_use:N \__dim_eval:w #1
-        \__prg_compare_error: \__dim_eval_end:
-      \prg_return_true:
-    \else:
-      \prg_return_false:
-    \fi:
+    \exp_after:wN \__dim_compare:w
+    \dim_use:N \__dim_eval:w #1 \__prg_compare_error:
   }
-\exp_args:Nno \use:nn
-  { \cs_new:Npn \__dim_compare_aux:w #1 }
-  { \tl_to_str:n { pt } }
-  #2 \__prg_compare_error:
+\cs_new:Npn \__dim_compare:w #1 \__prg_compare_error:
   {
-    \exp_after:wN \__dim_compare_aux:NNw #2 ?? \q_mark
-    #1 pt #2
+    \exp_after:wN \if_false: \tex_romannumeral:D -`0
+      \__dim_compare:wNN #1 ? { = \__dim_compare_end:w \else: } \q_stop
   }
-\cs_new:Npn \__dim_compare_aux:NNw #1#2#3 \q_mark
+\exp_args:Nno \use:nn
+  { \cs_new:Npn \__dim_compare:wNN #1 }
+  { \tl_to_str:n {pt} }
+  #2#3
   {
-    \use:c { __dim_compare_  #1  \if_meaning:w = #2 =  \fi: :NNw }
-      \__prg_compare_error:Nw #1
+      \if_meaning:w = #3
+        \use:c { __dim_compare_#2:w }
+      \fi:
+        #1 pt \exp_stop_f:
+      \prg_return_false:
+      \exp_after:wN \use_none_delimit_by_q_stop:w
+    \fi:
+    \reverse_if:N \if_dim:w #1 pt #2
+      \exp_after:wN \__dim_compare:wNN
+      \dim_use:N \__dim_eval:w #3
   }
-\cs_new:cpn { __dim_compare_=:NNw } #1#2#3 =
-  { \if_dim:w #3 = \__dim_eval:w }
-\cs_new:cpn { __dim_compare_<:NNw } #1#2#3 <
-  { \if_dim:w #3 < \__dim_eval:w }
-\cs_new:cpn { __dim_compare_>:NNw } #1#2#3 >
-  { \if_dim:w #3 > \__dim_eval:w }
-\cs_new:cpn { __dim_compare_==:NNw } #1#2#3 ==
-  { \if_dim:w #3 = \__dim_eval:w }
-\cs_new:cpn { __dim_compare_!=:NNw } #1#2#3 !=
-  { \reverse_if:N \if_dim:w #3 = \__dim_eval:w }
-\cs_new:cpn { __dim_compare_<=:NNw } #1#2#3 <=
-  { \reverse_if:N \if_dim:w #3 > \__dim_eval:w }
-\cs_new:cpn { __dim_compare_>=:NNw } #1#2#3 >=
-  { \reverse_if:N \if_dim:w #3 < \__dim_eval:w }
+\cs_new:cpn { __dim_compare_ ! :w }
+    #1 \reverse_if:N #2 ! #3 = { #1 #2 = #3 }
+\cs_new:cpn { __dim_compare_ = :w }
+    #1 \__dim_eval:w = { #1 \__dim_eval:w }
+\cs_new:cpn { __dim_compare_ < :w }
+    #1 \reverse_if:N #2 < #3 = { #1 #2 > #3 }
+\cs_new:cpn { __dim_compare_ > :w }
+    #1 \reverse_if:N #2 > #3 = { #1 #2 < #3 }
+\cs_new:Npn \__dim_compare_end:w #1 \prg_return_false: #2 \q_stop
+  { #1 \prg_return_false: \else: \prg_return_true: \fi: }
 \cs_new:Npn \dim_case:nnn #1
   {
     \tex_romannumeral:D
@@ -305,14 +299,8 @@
   { \skip_if_exist:NTF #1 { \skip_gzero:N #1 } { \skip_new:N #1 } }
 \cs_generate_variant:Nn \skip_zero_new:N  { c }
 \cs_generate_variant:Nn \skip_gzero_new:N { c }
-\cs_new_eq:NN \skip_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \skip_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \skip_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \skip_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \skip_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \skip_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \skip_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \skip_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \skip_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \skip_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new_protected:Npn \skip_set:Nn #1#2
   { #1 ~ \etex_glueexpr:D #2 \scan_stop: }
 \cs_new_protected:Npn \skip_gset:Nn { \tex_global:D \skip_set:Nn }
@@ -400,14 +388,8 @@
   { \muskip_if_exist:NTF #1 { \muskip_gzero:N #1 } { \muskip_new:N #1 } }
 \cs_generate_variant:Nn \muskip_zero_new:N  { c }
 \cs_generate_variant:Nn \muskip_gzero_new:N { c }
-\cs_new_eq:NN \muskip_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \muskip_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \muskip_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \muskip_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \muskip_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \muskip_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \muskip_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \muskip_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \muskip_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \muskip_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \cs_new_protected:Npn \muskip_set:Nn #1#2
   { #1 ~ \etex_muexpr:D #2 \scan_stop: }
 \cs_new_protected:Npn \muskip_gset:Nn { \tex_global:D \muskip_set:Nn }
@@ -443,25 +425,6 @@
 \muskip_new:N \l_tmpb_muskip
 \muskip_new:N \g_tmpa_muskip
 \muskip_new:N \g_tmpb_muskip
-\prg_new_conditional:Npnn \skip_if_infinite_glue:n #1 { p , T , F , TF }
-  { \skip_if_finite:nTF {#1} \prg_return_false: \prg_return_true: }
-\cs_new_eq:NN \prg_case_dim:nnn \dim_case:nnn
-\cs_new_eq:NN \dim_eval:w    \__dim_eval:w
-\cs_new_eq:NN \dim_eval_end: \__dim_eval_end:
-\cs_new_protected_nopar:Npn \dim_set_max:Nn
-  { \__dim_set_max:NNNn < \dim_set:Nn }
-\cs_new_protected_nopar:Npn \dim_gset_max:Nn
-  { \__dim_set_max:NNNn < \dim_gset:Nn }
-\cs_new_protected_nopar:Npn \dim_set_min:Nn
-  { \__dim_set_max:NNNn > \dim_set:Nn }
-\cs_new_protected_nopar:Npn \dim_gset_min:Nn
-  { \__dim_set_max:NNNn > \dim_gset:Nn }
-\cs_new_protected:Npn \__dim_set_max:NNNn #1#2#3#4
-  { \dim_compare:nNnT {#3} #1 {#4} { #2 #3 {#4} } }
-\cs_generate_variant:Nn \dim_set_max:Nn  { c }
-\cs_generate_variant:Nn \dim_gset_max:Nn { c }
-\cs_generate_variant:Nn \dim_set_min:Nn  { c }
-\cs_generate_variant:Nn \dim_gset_min:Nn { c }
 %% 
 %%
 %% End of file `l3skip.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty b/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty
index 6035dfe2f07..28148389931 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3tl.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3tl.dtx Copyright (C) 1990-2012 The LaTeX3 Project
+%% File: l3tl.dtx Copyright (C) 1990-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3tl.dtx 4339 2012-11-24 19:16:43Z joseph $
+\GetIdInfo$Id: l3tl.dtx 4415 2013-01-08 12:32:51Z bruno $
   {L3 Token lists}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -95,14 +95,8 @@
   { \tl_gset:Nx #1 { \exp_not:o {#2} \exp_not:o {#3} } }
 \cs_generate_variant:Nn \tl_concat:NNN  { ccc }
 \cs_generate_variant:Nn \tl_gconcat:NNN { ccc }
-\cs_new_eq:NN \tl_if_exist:NTF \cs_if_exist:NTF
-\cs_new_eq:NN \tl_if_exist:NT  \cs_if_exist:NT
-\cs_new_eq:NN \tl_if_exist:NF  \cs_if_exist:NF
-\cs_new_eq:NN \tl_if_exist_p:N \cs_if_exist_p:N
-\cs_new_eq:NN \tl_if_exist:cTF \cs_if_exist:cTF
-\cs_new_eq:NN \tl_if_exist:cT  \cs_if_exist:cT
-\cs_new_eq:NN \tl_if_exist:cF  \cs_if_exist:cF
-\cs_new_eq:NN \tl_if_exist_p:c \cs_if_exist_p:c
+\prg_new_eq_conditional:NNn \tl_if_exist:N \cs_if_exist:N { TF , T , F , p }
+\prg_new_eq_conditional:NNn \tl_if_exist:c \cs_if_exist:c { TF , T , F , p }
 \tl_const:Nn \c_empty_tl { }
 \tl_const:Nx \c_job_name_tl { \tex_jobname:D }
 \tl_const:Nn \c_space_tl { ~ }
@@ -743,7 +737,7 @@
   }
 \cs_new_protected:Npn \tl_show:N #1
   {
-    \cs_if_exist:NTF #1
+    \tl_if_exist:NTF #1
       { \cs_show:N #1 }
       {
         \__msg_kernel_error:nnx { kernel } { variable-not-defined }
@@ -757,21 +751,6 @@
 \tl_new:N \g_tmpb_tl
 \tl_new:N \l_tmpa_tl
 \tl_new:N \l_tmpb_tl
-\cs_new_eq:NN \tl_length_tokens:n \tl_count_tokens:n
-\cs_new_eq:NN \tl_length:N \tl_count:N
-\cs_new_eq:NN \tl_length:c \tl_count:c
-\cs_new_eq:NN \tl_length:n \tl_count:n
-\cs_new_eq:NN \tl_length:V \tl_count:V
-\cs_new_eq:NN \tl_length:o \tl_count:o
-\prg_new_conditional:Npnn \tl_if_empty:x #1 { p , T , F , TF }
-  { \__str_if_eq_x_return:nn { } {#1} }
-\prg_new_eq_conditional:NNn \tl_if_head_group:n \tl_if_head_is_group:n
-  { p , T , F , TF }
-\prg_new_eq_conditional:NNn \tl_if_head_N_type:n \tl_if_head_is_N_type:n
-  { p , T , F , TF }
-\prg_new_eq_conditional:NNn \tl_if_head_space:n \tl_if_head_is_space:n
-  { p , T , F , TF }
-\cs_new:Npn \tl_tail:w #1#2 \q_stop {#2}
 %% 
 %%
 %% End of file `l3tl.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3token.sty b/Master/texmf-dist/tex/latex/l3kernel/l3token.sty
index c4b3a28e6a5..5dd39858b49 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3token.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3token.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3token.dtx Copyright (C) 2005-2012 The LaTeX3 Project
+%% File: l3token.dtx Copyright (C) 2005-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,7 +46,7 @@
 %%
 %% -----------------------------------------------------------------------
 \RequirePackage{l3bootstrap}
-\GetIdInfo$Id: l3token.dtx 4384 2012-12-20 15:47:56Z bruno $
+\GetIdInfo$Id: l3token.dtx 4428 2013-01-10 13:23:29Z bruno $
   {L3 Experimental token manipulation}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -617,15 +617,13 @@
 \cs_new_protected_nopar:Npn \__peek_ignore_spaces_execute_branches:
   {
     \if_meaning:w \l_peek_token \c_space_token
-      \tex_afterassignment:D \__peek_ignore_spaces_execute_branches_aux:
-      \exp_after:wN \cs_set_eq:NN
-      \exp_after:wN \__peek_tmp:w
+      \exp_after:wN \peek_after:Nw
+      \exp_after:wN \__peek_ignore_spaces_execute_branches:
+      \tex_romannumeral:D -`0
     \else:
       \exp_after:wN \__peek_execute_branches:
     \fi:
   }
-\cs_new_protected_nopar:Npn \__peek_ignore_spaces_execute_branches_aux:
-  { \peek_after:Nw \__peek_ignore_spaces_execute_branches: }
 \group_begin:
   \cs_set:Npn \__peek_def:nnnn #1#2#3#4
     {
diff --git a/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty b/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
index 7411941082b..eff969849a0 100644
--- a/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
@@ -13,7 +13,7 @@
 %% 
 %% Do not distribute a modified version of this file.
 %% 
-%% File: l3keys2e.dtx (C) Copyright 2009,2011,2012 The LaTeX3 Project
+%% File: l3keys2e.dtx (C) Copyright 2009,2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -46,8 +46,8 @@
 %%
 %% -----------------------------------------------------------------------
 %%
-\RequirePackage{expl3}[2012/12/21]
-\@ifpackagelater{expl3}{2012/12/21}
+\RequirePackage{expl3}[2013/03/12]
+\@ifpackagelater{expl3}{2013/03/12}
   {}
   {%
     \PackageError{l3keys2e}{Support package l3kernel too old}
@@ -59,15 +59,15 @@
       }%
     \endinput
   }
-\GetIdInfo$Id: l3keys2e.dtx 4390 2012-12-21 06:59:20Z joseph $
+\GetIdInfo$Id: l3keys2e.dtx 4467 2013-03-12 08:29:05Z joseph $
   {LaTeX2e option processing using LaTeX3 keys}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
-\clist_new:N \__keys_latexe_options_clist
+\clist_new:N \l__keys_latexe_options_clist
 \bool_new:N \l__keys_process_class_bool
 \cs_new_protected:Npn \__keys_latexe_options:n #1
   {
-    \clist_clear:N \__keys_latexe_options_clist
+    \clist_clear:N \l__keys_latexe_options_clist
     \__keys_latexe_options_global:n {#1}
     \__keys_latexe_options_local:
     \keys_if_exist:nnF {#1} { unknown }
@@ -81,7 +81,7 @@
               }
           }
       }
-    \keys_set:nV {#1} \__keys_latexe_options_clist
+    \keys_set:nV {#1} \l__keys_latexe_options_clist
     \AtEndOfPackage { \cs_set_eq:NN \@unprocessedoptions \scan_stop: }
   }
 \cs_new_protected:Npn \__keys_latexe_options_global:n #1
@@ -99,12 +99,12 @@
 \cs_new_protected:Npn \__keys_latexe_options_class:n #1
   {
     \keys_if_exist:nnTF {#1} { unknown }
-      { \clist_put_right:No \__keys_latexe_options_clist \@classoptionslist }
+      { \clist_put_right:No \l__keys_latexe_options_clist \@classoptionslist }
       {
         \clist_map_inline:Nn \@classoptionslist
           {
             \keys_if_exist:nnTF {#1} { \__keys_latexe_remove_equals:n {##1} }
-              { \clist_put_right:Nn \__keys_latexe_options_clist {##1} }
+              { \clist_put_right:Nn \l__keys_latexe_options_clist {##1} }
               { \clist_put_right:Nn \@unusedoptionlist {##1} }
           }
       }
@@ -115,7 +115,7 @@
       {
         \keys_if_exist:nnT {#1} { \__keys_latexe_remove_equals:n {##1} }
           {
-            \clist_put_right:Nn \__keys_latexe_options_clist {##1}
+            \clist_put_right:Nn \l__keys_latexe_options_clist {##1}
             \clist_remove_all:Nn \@unusedoptionlist {##1}
           }
       }
@@ -126,7 +126,7 @@
       {
         \cs_if_exist:cT { opt@ \@currname . \@currext }
           {
-            \exp_args:NNc \clist_put_right:NV \__keys_latexe_options_clist
+            \exp_args:NNc \clist_put_right:NV \l__keys_latexe_options_clist
               { opt@ \@currname . \@currext }
           }
       }
diff --git a/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty b/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
index 16f16a26a13..fd2d7b22112 100644
--- a/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
@@ -17,7 +17,7 @@
 %%                      David Carlisle
 %%                  (C) Copyright 2004-2008 Frank Mittelbach,
 %%                      The LaTeX3 Project
-%%                  (C) Copyright 2009-2012 The LaTeX3 Project
+%%                  (C) Copyright 2009-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -50,8 +50,8 @@
 %%
 %% -----------------------------------------------------------------------
 %%
-\RequirePackage{expl3}[2012/12/21]
-\@ifpackagelater{expl3}{2012/12/21}
+\RequirePackage{expl3}[2013/03/12]
+\@ifpackagelater{expl3}{2013/03/12}
   {}
   {%
     \PackageError{xparse}{Support package l3kernel too old}
@@ -63,7 +63,7 @@
       }%
     \endinput
   }
-\GetIdInfo$Id: xparse.dtx 4390 2012-12-21 06:59:20Z joseph $
+\GetIdInfo$Id: xparse.dtx 4467 2013-03-12 08:29:05Z joseph $
   {L3 Experimental document command parser}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}
@@ -666,7 +666,15 @@
             \tl_if_in:nnTF {####1} {#1}
               { \__xparse_grab_D_nested:NNnnN #1 #2 {####1} {#3} #4 }
               {
-                \__xparse_add_arg:o { \use_none:n ####1 }
+                \tl_if_blank:oTF { \use_none:n ####1 }
+                  { \__xparse_add_arg:o { \use_none:n ####1 } }
+                  {
+                    \str_if_eq_x:nnTF
+                      { \exp_not:o { \use_none:n ####1 } }
+                      { { \exp_not:o { \use_ii:nnn ####1 \q_nil } } }
+                      { \__xparse_add_arg:o { \use_ii:nn ####1 } }
+                      { \__xparse_add_arg:o { \use_none:n ####1 } }
+                  }
                 #3 \l__xparse_args_tl
               }
           }
@@ -1131,7 +1139,15 @@
     \exp_args:No \tl_if_empty:oTF
       { #3 { \use_none:nnn } #2 \q__xparse #5 #4 \q__xparse #5 }
       {
-        \__xparse_put_arg_expandable:ow { \use_none:nn #1#2 }
+        \tl_if_blank:oTF { \use_none:nn #1#2 }
+          { \__xparse_put_arg_expandable:ow { } }
+          {
+            \str_if_eq_x:nnTF
+              { \exp_not:o { \use_none:nn #1#2 } }
+              { { \exp_not:o { \use_iii:nnnn #1#2 \q_nil } } }
+              { \__xparse_put_arg_expandable:ow { \use_iii:nnn #1#2 } }
+              { \__xparse_put_arg_expandable:ow { \use_none:nn #1#2 } }
+          }
           #6 \q__xparse #7
       }
       {
@@ -1155,7 +1171,18 @@
       { #4 {#3} \q__xparse #5 {#6} }
   }
 \cs_new:Npn \__xparse_expandable_grab_D_alt:Nwn #1#2 \q__xparse #3
-  { \__xparse_put_arg_expandable:ow { \use_none:n #3 } #2 \q__xparse #1 }
+  {
+    \tl_if_blank:oTF { \use_none:nn #1#2 }
+      { \__xparse_put_arg_expandable:ow { } }
+      {
+        \str_if_eq_x:nnTF
+          { \exp_not:o { \use_none:n #3 } }
+          { { \exp_not:o { \use_ii:nnn #3 \q_nil } } }
+          { \__xparse_put_arg_expandable:ow { \use_ii:nn #3 } }
+          { \__xparse_put_arg_expandable:ow { \use_none:n #3 } }
+      }
+      #2 \q__xparse #1
+  }
 \cs_new:Npn \__xparse_expandable_grab_m:w #1 \q__xparse #2
   { #2 { \__xparse_expandable_grab_m_aux:wNn #1 \q__xparse #2 } }
 \cs_new:Npn \__xparse_expandable_grab_m_aux:wNn #1 \q__xparse #2#3
@@ -1578,14 +1605,20 @@
 \cs_new_eq:NN \GetDocumentEnvironmmentArgSpec \__xparse_get_arg_spec:n
 \cs_new_eq:NN \ShowDocumentCommandArgSpec     \__xparse_show_arg_spec:N
 \cs_new_eq:NN \ShowDocumentEnvironmentArgSpec \__xparse_show_arg_spec:n
-\DeclareOption { log-declarations = true } { }
-\DeclareOption { log-declarations = false }
+\clist_new:N \l__xparse_options_clist
+\DeclareOption* { \clist_put_right:NV \l__xparse_options_clist \CurrentOption }
+\ProcessOptions \relax
+\keys_define:nn { xparse }
+  {
+    log-declarations .bool_set:N = \l__xparse_log_bool ,
+    log-declarations .initial:n  = true
+  }
+\keys_set:nV { xparse } \l__xparse_options_clist
+\bool_if:NF \l__xparse_log_bool
   {
     \msg_redirect_module:nnn { LaTeX / xparse } { info }    { none }
     \msg_redirect_module:nnn { LaTeX / xparse } { warning } { none }
   }
-\DeclareOption { log-declarations } { }
-\ProcessOptions \scan_stop:
 %% 
 %%
 %% End of file `xparse.sty'.
diff --git a/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty b/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
index 7c33f8c0803..38767bd6e67 100644
--- a/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
@@ -17,7 +17,7 @@
 %%                         David Carlisle
 %%                     (C) Copyright 2004-2010 Frank Mittelbach,
 %%                         The LaTeX3 Project
-%%                     (C) Copyright 2011,2012 The LaTeX3 Project
+%%                     (C) Copyright 2011-2013 The LaTeX3 Project
 %%
 %% It may be distributed and/or modified under the conditions of the
 %% LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -50,8 +50,8 @@
 %%
 %% -----------------------------------------------------------------------
 %%
-\RequirePackage{expl3}[2012/12/21]
-\@ifpackagelater{expl3}{2012/12/21}
+\RequirePackage{expl3}[2013/03/12]
+\@ifpackagelater{expl3}{2013/03/12}
   {}
   {%
     \PackageError{xtemplate}{Support package l3kernel too old}
@@ -63,7 +63,7 @@
       }%
     \endinput
   }
-\GetIdInfo$Id: xtemplate.dtx 4390 2012-12-21 06:59:20Z joseph $
+\GetIdInfo$Id: xtemplate.dtx 4467 2013-03-12 08:29:05Z joseph $
   {L3 Experimental prototype document functions}
 \ProvidesExplPackage
   {\ExplFileName}{\ExplFileDate}{\ExplFileVersion}{\ExplFileDescription}