l3 (2feb21)

git-svn-id: svn://tug.org/texlive/trunk@57600 c570f23f-e606-0410-a88d-b1316a301751

10 files changed, 118 insertions, 3960 deletions

diff --git a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
index b182df9e3ba..cd3f5206a95 100644
--- a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.dtx
@@ -2,7 +2,7 @@
 %
 %% File: l3keys2e.dtx
 %
-% Copyright (C) 2009,2011-2020 The LaTeX3 Project
+% Copyright (C) 2009,2011-2021 The LaTeX Project
 %
 % It may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -54,7 +54,7 @@
 % }
 %
 % \author{^^A
-%  The \LaTeX3 Project\thanks
+%  The \LaTeX{} Project\thanks
 %    {^^A
 %      E-mail:
 %        \href{mailto:latex-team@latex-project.org}
@@ -62,7 +62,7 @@
 %    }^^A
 % }
 %
-% \date{Released 2020-10-27}
+% \date{Released 2021-02-02}
 %
 % \maketitle
 %
@@ -139,7 +139,7 @@
 %    \end{macrocode}
 %
 %    \begin{macrocode}
-\ProvidesExplPackage{l3keys2e}{2020-10-27}{}
+\ProvidesExplPackage{l3keys2e}{2021-02-02}{}
   {LaTeX2e option processing using LaTeX3 keys}
 %    \end{macrocode}
 %
diff --git a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.ins b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.ins
index a5d2f4e3017..f5b81f896be 100644
--- a/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.ins
+++ b/Master/texmf-dist/source/latex/l3packages/l3keys2e/l3keys2e.ins
@@ -2,7 +2,7 @@
 
 File: l3keys2e.ins
 
-Copyright (C) 2009,2011,2012,2016,2017,2019,2020 The LaTeX3 Project
+Copyright (C) 2009,2011,2012,2016,2017,2019-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of the
 LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -23,7 +23,7 @@ The released version of this bundle is available from CTAN.
 
 \preamble
 
-Copyright (C) 2009-2020 The LaTeX3 Project
+Copyright (C) 2009-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of
 the LaTeX Project Public License (LPPL), either version 1.3c of
diff --git a/Master/texmf-dist/source/latex/l3packages/xfp/xfp.dtx b/Master/texmf-dist/source/latex/l3packages/xfp/xfp.dtx
index 6a0b66ef5a3..7a86c63782b 100644
--- a/Master/texmf-dist/source/latex/l3packages/xfp/xfp.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xfp/xfp.dtx
@@ -2,7 +2,7 @@
 %
 %% File: xfp.dtx
 %
-% Copyright (C) 2017-2020 The LaTeX3 Project
+% Copyright (C) 2017-2021 The LaTeX Project
 %
 % It may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -56,7 +56,7 @@
 % }
 %
 % \author{^^A
-%  The \LaTeX3 Project\thanks
+%  The \LaTeX{} Project\thanks
 %    {^^A
 %      E-mail:
 %        \href{mailto:latex-team@latex-project.org}
@@ -64,7 +64,7 @@
 %    }^^A
 % }
 %
-% \date{Released 2020-10-27}
+% \date{Released 2021-02-02}
 %
 % \maketitle
 %
@@ -167,7 +167,7 @@
 %    \end{macrocode}
 %
 %    \begin{macrocode}
-\ProvidesExplPackage{xfp}{2020-10-27}{}
+\ProvidesExplPackage{xfp}{2021-02-02}{}
   {L3 Floating point unit}
 %    \end{macrocode}
 %
diff --git a/Master/texmf-dist/source/latex/l3packages/xfp/xfp.ins b/Master/texmf-dist/source/latex/l3packages/xfp/xfp.ins
index 2439b0aae10..736445226bf 100644
--- a/Master/texmf-dist/source/latex/l3packages/xfp/xfp.ins
+++ b/Master/texmf-dist/source/latex/l3packages/xfp/xfp.ins
@@ -2,7 +2,7 @@
 
 File: xfp.ins
 
-Copyright (C) 2017,2019,2020 The LaTeX3 Project
+Copyright (C) 2017,2019-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of the
 LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -23,7 +23,7 @@ The released version of this bundle is available from CTAN.
 
 \preamble
 
-Copyright (C) 2017-2020 The LaTeX3 Project
+Copyright (C) 2017-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of
 the LaTeX Project Public License (LPPL), either version 1.3c of
diff --git a/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx b/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx
index c7fe59aba81..dfdbf25f6aa 100644
--- a/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.dtx
@@ -3,7 +3,7 @@
 %% File: xfrac.dtx
 % 
 % Copyright (C) 2004,2008-2010 Morten Hoegholm
-%           (C) 2011,2012,2014-2020 The LaTeX3 Project
+%           (C) 2011,2012,2014-2021 The LaTeX Project
 %
 % It may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -57,7 +57,7 @@
 % }
 %
 % \author{^^A
-%  The \LaTeX3 Project\thanks
+%  The \LaTeX{} Project\thanks
 %    {^^A
 %      E-mail:
 %        \href{mailto:latex-team@latex-project.org}
@@ -65,7 +65,7 @@
 %    }^^A
 % }
 %
-% \date{Released 2020-10-27}
+% \date{Released 2021-02-02}
 %
 % \maketitle
 %
@@ -535,7 +535,7 @@
 %    \end{macrocode}
 %
 %    \begin{macrocode}
-\ProvidesExplPackage{xfrac}{2020-10-27}{}
+\ProvidesExplPackage{xfrac}{2021-02-02}{}
   {L3 Experimental split-level fractions}
 %    \end{macrocode}
 %
diff --git a/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.ins b/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.ins
index 9126baaab7b..d08a89b6d36 100644
--- a/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.ins
+++ b/Master/texmf-dist/source/latex/l3packages/xfrac/xfrac.ins
@@ -3,7 +3,7 @@
 File: xfrac.ins
 
 Copyright (C) 2004,2008-2010 Morten Hoegholm
-          (C) 2011,2012,2016,2017,2019,2020 The LaTeX3 Project
+          (C) 2011,2012,2016,2017,2019-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of the
 LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -25,7 +25,7 @@ The released version of this bundle is available from CTAN.
 \preamble
 
 Copyright (C) 2004,2008-2010 Morten Hoegholm
-          (C) 2011-2020 The LaTeX3 Project
+          (C) 2011-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of
 the LaTeX Project Public License (LPPL), either version 1.3c of
diff --git a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
index b6c490df177..3ea422301a5 100644
--- a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.dtx
@@ -3,8 +3,8 @@
 %% File: xparse.dtx
 %
 % Copyright (C) 1999 Frank Mittelbach, Chris Rowley, David Carlisle
-%           (C) 2004-2008 Frank Mittelbach, The LaTeX3 Project
-%           (C) 2009-2020 The LaTeX3 Project
+%           (C) 2004-2008 Frank Mittelbach, The LaTeX Project
+%           (C) 2009-2021 The LaTeX Project
 %
 % It may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -59,7 +59,7 @@
 % }
 %
 % \author{^^A
-%  The \LaTeX3 Project\thanks
+%  The \LaTeX{} Project\thanks
 %    {^^A
 %      E-mail:
 %        \href{mailto:latex-team@latex-project.org}
@@ -67,7 +67,7 @@
 %    }^^A
 % }
 %
-% \date{Released 2020-10-27}
+% \date{Released 2021-02-02}
 %
 % \maketitle
 %
@@ -928,7 +928,7 @@
 % \begin{function}{\GetDocumentCommandArgSpec, \GetDocumentEnvironmentArgSpec}
 %   \begin{syntax}
 %     \cs{GetDocumentCommandArgSpec} \meta{function}
-%     \cs{GetDocumentEnvironmentArgSpec} \meta{environment}
+%     \cs{GetDocumentEnvironmentArgSpec} \Arg{environment}
 %   \end{syntax}
 %   These functions transfer the current argument specification for the
 %   requested \meta{function} or \meta{environment} into the token list
@@ -942,7 +942,7 @@
 %   {\ShowDocumentCommandArgSpec,  \ShowDocumentEnvironmentArgSpec}
 %   \begin{syntax}
 %     \cs{ShowDocumentCommandArgSpec} \meta{function}
-%     \cs{ShowDocumentEnvironmentArgSpec} \meta{environment}
+%     \cs{ShowDocumentEnvironmentArgSpec} \Arg{environment}
 %   \end{syntax}
 %   These functions show the current argument specification for the
 %   requested \meta{function} or \meta{environment} at the terminal. If
@@ -970,1107 +970,159 @@
 % \section{\pkg{xparse} implementation}
 %
 %    \begin{macrocode}
-%<@@=xparse>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*2ekernel>
-\everyjob\expandafter{\the\everyjob
-  \message{xparse <2020-03-03>}%
-}
-\ExplSyntaxOn
-%</2ekernel>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*package>
-\ProvidesExplPackage{xparse}{2020-10-27}{}
-  {L3 Experimental document command parser}
-%    \end{macrocode}
-%
-% \subsection{Package options}
-%
-% \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}
-\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  = false
-  }
-\keys_set:nV { xparse } \l_@@_options_clist
-\bool_if:NF \l_@@_log_bool
-  { \msg_redirect_module:nnn { LaTeX / xparse } { info } { none } }
-%</package>
-%    \end{macrocode}
-% \end{variable}
-% \end{variable}
-%
-% \subsection{Catcode regime check}
-%
-%    \begin{macrocode}
-%<*core>
-\if_charcode:w xx
-  \cs_gset:Npn \@@_file_end_hook: { }
-\else
-  \ExplSyntaxOn
-  \cs_gset:Npn \@@_file_end_hook: { \ExplSyntaxOff }
-\fi:
-%</core>
-%    \end{macrocode}
-%
-% \subsection{Reload check}
-%
-% A simple reload check.
-%    \begin{macrocode}
-%<*core>
-\cs_if_exist:NT \NewDocumentCommand
-  { \file_input_stop: }
-%</core>
-%    \end{macrocode}
-%
-%  Load the core code. We use \tn{input} here as there can be
-%  an issue if the user has |openin_any = p| with older binaries.
-%    \begin{macrocode}
 %<*2ekernel|package>
-\input xparse-generic.tex ~
-%</2ekernel|package>
 %    \end{macrocode}
 %
-% \subsection{Variables and constants}
-%
-%    \begin{macrocode}
-%<*core>
-%    \end{macrocode}
-%
-% \begin{variable}{\l_@@_arg_spec_tl}
-%   Holds the argument specification after normalization of shorthands.
-%    \begin{macrocode}
-\tl_new:N \l_@@_arg_spec_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_args_tl}
-%   Token list variable for grabbed arguments.
-%    \begin{macrocode}
-\tl_new:N \l_@@_args_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_args_i_tl, \l_@@_args_ii_tl}
-%   Hold the modified arguments when dealing with default values or
-%   processors.
-%    \begin{macrocode}
-\tl_new:N \l_@@_args_i_tl
-\tl_new:N \l_@@_args_ii_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_current_arg_int}
-%   The number of the current argument being set up: this is used to
-%   make sure there are at most 9 arguments, then for creating the
-%   expandable auxiliary functions and knowing how many arguments the
-%   code function should take.
-%    \begin{macrocode}
-\int_new:N \l_@@_current_arg_int
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_defaults_bool, \l_@@_defaults_tl}
-%   The boolean indicates whether there are any argument with default
-%   value other than |-NoValue-|; the token list holds the code to
-%   determine these default values in terms of other arguments.
-%    \begin{macrocode}
-\bool_new:N \l_@@_defaults_bool
-\tl_new:N \l_@@_defaults_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_environment_bool}
-%   Generating environments uses the same mechanism as generating functions.
-%   However, full processing of arguments is always needed for environments,
-%   and so the function-generating code needs to know this.
-%   This variable is also used at run time to give correct error messages.
 %    \begin{macrocode}
-\bool_new:N \l_@@_environment_bool
+%<@@=cmd>
 %    \end{macrocode}
-% \end{variable}
 %
-% \begin{variable}{\l_@@_environment_str}
-%   Name of the environment, used at definition time and at run time.
-%    \begin{macrocode}
-\str_new:N \l_@@_environment_str
-%    \end{macrocode}
-% \end{variable}
+% This package file, along with the frozen versions in
+% \pkg{xparse-2018-04-12}, \pkg{xparse-2020-10-01}, and
+% |xparse-generic.tex|, is intended to work across different \LaTeX{}
+% releases, respected the minimum \pkg{expl3} version required by
+% \pkg{xparse}.
 %
-% \begin{variable}{\l_@@_expandable_bool}
-%   Used to indicate if an expandable command is begin generated, as this
-%   affects both the acceptable argument types and how they are implemented.
-%    \begin{macrocode}
-\bool_new:N \l_@@_expandable_bool
-%    \end{macrocode}
-% \end{variable}
+% We can't use the \pkg{latexrelease} mechanism with \cs{DeclareRelease}
+% here because cases of rolling forwards or backwards differ, due to the
+% prefix change from |xparse| to |cmd|, so we do our own checks to
+% ensure the right version is loaded.
 %
-% \begin{variable}{\l_@@_expandable_aux_name_tl}
-%   Used to create pretty-printing names for the auxiliaries: although the
-%   immediate definition does not vary, the full expansion does and so it
-%   does not count as a constant.
-%    \begin{macrocode}
-\tl_new:N \l_@@_expandable_aux_name_tl
-\tl_set:Nn \l_@@_expandable_aux_name_tl
-  {
-    \l_@@_function_tl \c_space_tl
-    ( arg~ \int_use:N \l_@@_current_arg_int )
-  }
-%    \end{macrocode}
-% \end{variable}
+% All this loading assumes that if \pkg{latexrelease} should be loaded,
+% it is before \pkg{xparse}.  The other way around was not tested at all
+% and is likely to break.
 %
-% \begin{variable}{\g_@@_grabber_int}
-%   Used (in exceptional cases) to get unique names for grabbers used by
-%   expandable commands.
-%    \begin{macrocode}
-\int_new:N \g_@@_grabber_int
-%    \end{macrocode}
-% \end{variable}
+% In releases prior to 2020-10-01, \cs{NewDocumentCommand} is undefined,
+% so \pkg{xparse} was not loaded, thus we can load the full version from
+% \pkg{xparse-2018-04-12}.  Otherwise we will load only the deprecated
+% argument types from \pkg{xparse-2020-10-01}.  If we're in |2ekernel|
+% mode, it means rolling forward so load only the code code from
+% |xparse-generic.tex|.
 %
-% \begin{variable}{\l_@@_fn_tl}
-%   For passing the pre-formed name of the auxiliary to be used as the
-%   parsing function.
-%    \begin{macrocode}
-\tl_new:N \l_@@_fn_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_fn_code_tl}
-%   For passing the pre-formed name of the auxiliary that contains the
-%   actual code.
-%    \begin{macrocode}
-\tl_new:N \l_@@_fn_code_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_function_tl}
-%   Holds the control sequence name of the function currently being
-%   defined: used to avoid passing this as an argument and to avoid repeated
-%   use of \cs{cs_to_str:N}.
-%    \begin{macrocode}
-\tl_new:N \l_@@_function_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_grab_expandably_bool}
-%   When defining a non-expandable command, indicates whether the
-%   arguments can all safely be grabbed by expandable grabbers.  This is
-%   to support abuses of \pkg{xparse} that use protected functions
-%   inside csname constructions.
-%    \begin{macrocode}
-\bool_new:N \l_@@_grab_expandably_bool
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_obey_spaces_bool}
-%   For trailing optionals.
-%    \begin{macrocode}
-\bool_new:N \l_@@_obey_spaces_bool
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_last_delimiters_tl}
-%   Holds the delimiters (first tokens) of all optional arguments since
-%   the previous mandatory argument, to warn about cases where it would
-%   be impossible to omit optional arguments completely because the
-%   following mandatory argument has the same delimiter as one of the
-%   optional arguments.
-%    \begin{macrocode}
-\tl_new:N \l_@@_last_delimiters_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_long_bool}
-%   Used to indicate that an argument is long, on a per-argument basis.
-%    \begin{macrocode}
-\bool_new:N \l_@@_long_bool
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_m_args_int}
-%   The number of \texttt{m} arguments: if this is the same as the total
-%   number of arguments, then a short-cut can be taken in the creation of
-%   the grabber code.
-%    \begin{macrocode}
-\int_new:N \l_@@_m_args_int
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_prefixed_bool}
-%   When preparing the signature of non-expandable commands, indicates
-%   that the current argument is affected by a processor or by |+|
-%   (namely is long).
-%    \begin{macrocode}
-\bool_new:N \l_@@_prefixed_bool
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_process_all_tl, \l_@@_process_one_tl, \l_@@_process_some_bool}
-%   When preparing the signature, the processors that will be applied to
-%   a given argument are collected in \cs{l_@@_process_one_tl}, while
-%   \cs{l_@@_process_all_tl} contains processors for all arguments.  The
-%   boolean indicates whether there are any processors (to bypass the
-%   whole endeavour otherwise).
-%    \begin{macrocode}
-\tl_new:N \l_@@_process_all_tl
-\tl_new:N \l_@@_process_one_tl
-\bool_new:N \l_@@_process_some_bool
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_saved_args_tl}
-%   Stores \cs{l_@@_args_tl} to deal with space-trimming of
-%   \texttt{b}-type arguments.
-%    \begin{macrocode}
-\tl_new:N \l_@@_saved_args_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_signature_tl}
-%   Used when constructing the signature (code for argument grabbing) to
-%   hold what will become the implementation of the main function.
-%   When arguments are grabbed (at point of use of the command/environment),
-%   it also stores the code for grabbing the remaining arguments.
-%    \begin{macrocode}
-\tl_new:N \l_@@_signature_tl
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}
-%   {\l_@@_some_obey_spaces_bool, \l_@@_some_long_bool, \l_@@_some_short_bool}
-%   These flags are set while normalizing the argument specification.
-%   The \texttt{obey_spaces} one is used to detect when |!| is used on
-%   an argument that is not a trailing optional argument.
-%   The other two are used to check whether all short arguments appear
-%   before long arguments: this is needed to grab arguments expandably.
-%   As soon as the first long argument is seen (other than
-%   \texttt{t}-type, whose long status is ignored) the
-%   \texttt{some_long} flag is set.  The \texttt{some_short} flag is
-%   used for expandable commands, to know whether to define a short
-%   auxiliary too.
-%    \begin{macrocode}
-\bool_new:N \l_@@_some_obey_spaces_bool
-\bool_new:N \l_@@_some_long_bool
-\bool_new:N \l_@@_some_short_bool
-%    \end{macrocode}
-% \end{variable}
-%
-% \begin{variable}{\l_@@_tmp_prop, \l_@@_tmpa_tl, \l_@@_tmpb_tl}
-% \begin{macro}{\@@_tmp:w}
-%   Scratch space.
-%    \begin{macrocode}
-\prop_new:N \l_@@_tmp_prop
-\tl_new:N \l_@@_tmpa_tl
-\tl_new:N \l_@@_tmpb_tl
-\cs_new_eq:NN \@@_tmp:w ?
-%    \end{macrocode}
-% \end{macro}
-% \end{variable}
-%
-% \subsection{Declaring commands and environments}
-%
-% \begin{macro}{\@@_declare_cmd:Nnn, \@@_declare_expandable_cmd:Nnn}
-% \begin{macro}{\@@_declare_cmd_aux:Nnn}
-% \begin{macro}
-%   {\@@_declare_cmd_internal:Nnnn, \@@_declare_cmd_internal:cnxn}
-%   The main functions for creating commands set the appropriate flag then
-%   use the same internal code to do the definition.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_cmd:Nnn
-  {
-    \bool_set_false:N \l_@@_expandable_bool
-    \@@_declare_cmd_aux:Nnn
-  }
-\cs_new_protected:Npn \@@_declare_expandable_cmd:Nnn
-  {
-    \bool_set_true:N \l_@@_expandable_bool
-    \@@_declare_cmd_aux:Nnn
-  }
-%    \end{macrocode}
-%  The first stage is to log information, both for the user in the log and
-%  for programmatic use in a property list of all declared commands.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_cmd_aux:Nnn #1#2#3
-  {
-    \cs_if_exist:NTF #1
-      {
-        \__kernel_msg_info:nnxx { xparse } { redefine-command }
-          { \token_to_str:N #1 } { \tl_to_str:n {#2} }
-      }
-      {
-        \bool_lazy_or:nnT
-          { \cs_if_exist_p:c { \cs_to_str:N #1 ~ code } }
-          { \cs_if_exist_p:c { \cs_to_str:N #1 ~ defaults } }
-          {
-            \__kernel_msg_warning:nnx { xparse } { unsupported-let }
-              { \token_to_str:N #1 }
-          }
-        \__kernel_msg_info:nnxx { xparse } { define-command }
-          { \token_to_str:N #1 } { \tl_to_str:n {#2} }
-      }
-    \bool_set_false:N \l_@@_environment_bool
-    \@@_declare_cmd_internal:Nnnn #1 {#2} {#3} { }
-  }
-%    \end{macrocode}
-%   At definition time, the variable \cs{l_@@_fn_tl} is only used for error messages.
-%   The real business of defining a document command starts with setting up
-%   the appropriate name, then normalizing the argument specification to get rid of
-%   shorthands.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_cmd_internal:Nnnn #1#2#3#4
-  {
-    \tl_set:Nx \l_@@_function_tl { \cs_to_str:N #1 }
-    \tl_set:Nx \l_@@_fn_tl
-      { \exp_not:c { \l_@@_function_tl \c_space_tl } }
-    \@@_normalize_arg_spec:n {#2}
-    \exp_args:No \@@_prepare_signature:n \l_@@_arg_spec_tl
-    \@@_declare_cmd_code:Nnn #1 {#2} {#3}
-    #4
-    \@@_break_point:n {#2}
-  }
-\cs_generate_variant:Nn \@@_declare_cmd_internal:Nnnn { cnx }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_break_point:n}
-%   A marker used to escape from creating a definition if necessary.
-%    \begin{macrocode}
-\cs_new_eq:NN \@@_break_point:n \use_none:n
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_declare_cmd_code:Nnn}
-% \begin{macro}
-%   {\@@_declare_cmd_code_aux:Nnn, \@@_declare_cmd_code_expandable:Nnn}
-%   The appropriate auxiliary is called.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_cmd_code:Nnn
-  {
-    \bool_if:NTF \l_@@_grab_expandably_bool
-      { \@@_declare_cmd_code_expandable:Nnn }
-      { \@@_declare_cmd_code_aux:Nnn }
-   }
-%    \end{macrocode}
-%   Standard functions call \cs{@@_start:nNNnnn}, which receives the
-%   argument specification, an auxiliary used for
-%   grabbing arguments, an auxiliary containing the code, and then the
-%   signature, default arguments, and processors.
+% In |2ekernel| mode we anticipate the definition of two macros to parse
+% dates so that we can compare \cs{fmtdate} properly.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_cmd_code_aux:Nnn #1#2#3
+%<*2ekernel>
+\def\@parse@version#1/#2/#3#4#5\@nil{%
+  \@parse@version@dash#1-#2-#3#4\@nil}
+\def\@parse@version@dash#1-#2-#3#4#5\@nil{%
+  \if\relax#2\relax\else#1\fi#2#3#4 }
+%</2ekernel>
+\ExplSyntaxOn
+\cs_if_free:NTF \NewDocumentCommand
   {
-    \cs_generate_from_arg_count:cNnn
-      { \l_@@_function_tl \c_space_tl code }
-      \cs_set_protected:Npn \l_@@_current_arg_int {#3}
-    \cs_set_protected_nopar:Npx #1
-      {
-        \bool_if:NTF \l_@@_environment_bool
-          {
-            \@@_start_env:nnnnn { \exp_not:n {#2} }
-              { \l_@@_environment_str }
-          }
-          {
-            \@@_start:nNNnnn { \exp_not:n {#2} }
-              \exp_not:c { \l_@@_function_tl \c_space_tl }
-              \exp_not:c { \l_@@_function_tl \c_space_tl code }
-          }
-          { \exp_not:o \l_@@_signature_tl }
-          {
-            \bool_if:NT \l_@@_defaults_bool
-              { \exp_not:o \l_@@_defaults_tl }
-          }
-          {
-            \bool_if:NT \l_@@_process_some_bool
-              { \exp_not:o \l_@@_process_all_tl }
-          }
-      }
+    \ExplSyntaxOff
+    \ifnum\expandafter
+        \@parse@version\fmtversion//00\@nil <
+        \@parse@version 2020-10-01//00\@nil
+      \RequirePackage{xparse-2018-04-12}
+    \else
+%<2ekernel>      \@@@@input xparse-generic.tex ~
+%<package>      \RequirePackage{xparse-2020-10-01}
+    \fi
+    \file_input_stop:
   }
-%    \end{macrocode}
-%   Expandable functions and functions whose arguments can be grabbed
-%   expandably call \cs{@@_start_expandable:nNNNNn}, which receives the
-%   argument specification, four auxiliaries (two for grabbing arguments, one for
-%   the code, and one for default arguments), and finally the signature.
-%   Non-expandable functions that take this branch should nevertheless
-%   be protected, as well as their \texttt{code} function.  They will
-%   only be expanded in contexts such as constructing a csname.
-%   The two grabbers (named after the function with one or two spaces)
-%   are needed when there are both short and long arguments; otherwise
-%   the same grabber is included twice in the definition.  If all
-%   arguments are long or all are short the (only) grabber is defined
-%   correspondingly to be long/short.  Otherwise two grabbers are
-%   defined, one long, one short.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_cmd_code_expandable:Nnn #1#2#3
-  {
-    \exp_args:Ncc \cs_generate_from_arg_count:NNnn
-      { \l_@@_function_tl \c_space_tl code }
-      { cs_set \bool_if:NF \l_@@_expandable_bool { _protected } :Npn }
-      \l_@@_current_arg_int {#3}
-    \bool_if:NT \l_@@_defaults_bool
-      {
-        \use:x
-          {
-            \cs_generate_from_arg_count:cNnn
-              { \l_@@_function_tl \c_space_tl defaults }
-              \cs_set:Npn \l_@@_current_arg_int
-              { \exp_not:o \l_@@_defaults_tl }
-          }
-      }
-    \bool_if:NTF \l_@@_expandable_bool
-      { \cs_set_nopar:Npx } { \cs_set_protected_nopar:Npx } #1
-      {
-        \exp_not:N \@@_start_expandable:nNNNNn
-          { \exp_not:n {#2} }
-          \exp_not:c { \l_@@_function_tl \c_space_tl }
-          \exp_not:c
-            {
-              \l_@@_function_tl \c_space_tl
-              \bool_if:NT \l_@@_some_short_bool
-                { \bool_if:NT \l_@@_some_long_bool { \c_space_tl } }
-            }
-          \exp_not:c { \l_@@_function_tl \c_space_tl code }
-          \bool_if:NTF \l_@@_defaults_bool
-            { \exp_not:c { \l_@@_function_tl \c_space_tl defaults } }
-            { ? }
-          { \exp_not:o \l_@@_signature_tl }
-      }
-    \bool_if:NTF \l_@@_some_long_bool
-      {
-        \bool_if:NT \l_@@_some_short_bool
-          {
-            \cs_set_nopar:cpx { \l_@@_function_tl \c_space_tl \c_space_tl }
-              ##1##2 { ##1 {##2} }
-          }
-        \cs_set:cpx
-      }
-      { \cs_set_nopar:cpx }
-          { \l_@@_function_tl \c_space_tl } ##1##2 { ##1 {##2} }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
 %
-% \begin{macro}{\@@_declare_env:nnnn}
-% \begin{macro}{\@@_declare_env_internal:nnnn}
-%   The lead-off to creating an environment is much the same as that for
-%   creating a command: issue the appropriate message, store the argument
-%   specification then hand off to an internal function.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_env:nnnn #1#2
-  {
-    \str_set:Nx \l_@@_environment_str {#1}
-    \str_set:Nx \l_@@_environment_str
-      { \tl_trim_spaces:o { \l_@@_environment_str } }
-    \cs_if_exist:cTF { \l_@@_environment_str }
-      {
-        \__kernel_msg_info:nnxx { xparse } { redefine-environment }
-          { \l_@@_environment_str } { \tl_to_str:n {#2} }
-      }
-      {
-        \__kernel_msg_info:nnxx { xparse } { define-environment }
-          { \l_@@_environment_str } { \tl_to_str:n {#2} }
-      }
-    \bool_set_false:N \l_@@_expandable_bool
-    \bool_set_true:N \l_@@_environment_bool
-    \exp_args:NV \@@_declare_env_internal:nnnn
-      \l_@@_environment_str {#2}
-  }
+% In case \cs{NewDocumentCommand} is already defined, we're either in
+% \LaTeX{} 2020-10-01 or later.  In the former case, the code loaded in
+% the kernel has the |__xparse| prefix, so we'll load
+% \pkg{xparse-2020-10-01}, otherwise we'll continue in |xparse.sty|,
+% which contains the final remains of \pkg{xparse} with the |__cmd|
+% prefix.  To check that we simply look at an internal command with the
+% |__cmd| prefix.
 %    \end{macrocode}
-%   Creating a document environment requires a few more steps than creating
-%   a single command. In order to pass the arguments of the command to the
-%   end of the function, it is necessary to store the grabbed arguments.
-%   To do that, the function used at the end of the environment has to be
-%   redefined to contain the appropriate information. To minimize the amount
-%   of expansion at point of use, the code here is expanded now as well as
-%   when used.
-%   The last argument of \cs{@@_declare_cmd_internal:Nnnn} is only run
-%   if the definition succeeded.  In package mode this ensures that the
-%   original definition of the environment is not changed if the
-%   definition fails for any reason.  This also avoids an error when
-%   defining the \verb*|end aux | function when the user asks for more
-%   than $9$ arguments.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_declare_env_internal:nnnn #1#2#3#4
   {
-    \@@_declare_cmd_internal:cnxn { environment~ #1 } {#2}
-      {
-        \cs_set_nopar:Npx \exp_not:c { environment~ #1 ~end~aux }
-          {
-            \exp_not:N \exp_not:N \exp_not:c { environment~ #1~end~aux~ }
-            \exp_not:n { \exp_not:o \l_@@_args_tl }
-          }
-        \exp_not:n {#3}
-      }
+    \ExplSyntaxOff
+    \cs_if_exist:NF \@@_start:nNNnnn
       {
-        \cs_set_nopar:cpx { environment~ #1 ~end }
-          { \exp_not:c { environment~ #1 ~end~aux } }
-        \cs_generate_from_arg_count:cNnn
-          { environment~ #1 ~end~aux~ } \cs_set:Npn
-          \l_@@_current_arg_int {#4}
-        \cs_set_eq:cc {#1}       { environment~ #1 }
-        \cs_set_eq:cc { end #1 } { environment~ #1 ~end }
+        \RequirePackage{xparse-2020-10-01}
+        \file_input_stop:
       }
   }
+\ExplSyntaxOff
 %    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Structure of \pkg{xparse} commands}
-%
-% \begin{macro}{\@@_start_env:nnnnn, \@@_start:nNNnnn}
-%   For error messages that occur during run-time when getting arguments
-%   of environments it is necessary to keep track of the environment
-%   name.  We begin non-expandable commands with a token equal to
-%   \cs{scan_stop:}, whose name gives a reasonable error message if the
-%   command is used inside a csname and protects against
-%   \texttt{f}-expansion.  This is useless for environments since
-%   \cs{begin} is already not expandable.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_start_env:nnnnn #1#2
-  {
-    \cs_if_exist_use:N \conditionally@traceoff
-    \str_set:Nn \l_@@_environment_str {#2}
-    \bool_set_true:N \l_@@_environment_bool
-    \@@_start_aux:ccnnnn
-      { environment~ \l_@@_environment_str \c_space_tl }
-      { environment~ \l_@@_environment_str \c_space_tl code }
-      {#1}
-  }
-\cs_new_protected:Npx \@@_start:nNNnnn #1#2#3
-  {
-    \exp_not:n { \cs_if_exist_use:N \conditionally@traceoff }
-    \exp_not:c { xparse~function~is~not~expandable }
-    \exp_not:n { \bool_set_false:N \l_@@_environment_bool }
-    \exp_not:N \@@_start_aux:NNnnnn
-    #2 #3 {#1}
-  }
-%    \end{macrocode}
-% \end{macro}
 %
-% \begin{macro}{\@@_start_aux:NNnnnn, \@@_start_aux:ccnnnn}
-%   This sets up a few variables to minimize the boilerplate code
-%   included in all \pkg{xparse}-defined commands.  It then runs the
-%   grabbers~|#4|.  Again, the argument specification |#1| is only for
-%   diagnostics.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_start_aux:NNnnnn #1#2#3#4#5#6
-  {
-    \tl_clear:N \l_@@_args_tl
-    \tl_set:Nn \l_@@_fn_tl {#1}
-    \tl_set:Nn \l_@@_fn_code_tl {#2}
-    \tl_set:Nn \l_@@_defaults_tl {#5}
-    \tl_set:Nn \l_@@_process_all_tl {#6}
-    #4 \@@_run_code:
-  }
-\cs_generate_variant:Nn \@@_start_aux:NNnnnn { cc }
+%</2ekernel|package>
 %    \end{macrocode}
-% \end{macro}
 %
-% \begin{macro}{\@@_run_code:}
-%   After arguments are grabbed, this function is responsible for
-%   inserting default values, running processors, and finally running
-%   the code.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_run_code:
-  {
-    \tl_if_empty:NF \l_@@_defaults_tl { \@@_defaults: }
-    \tl_if_empty:NF \l_@@_process_all_tl { \@@_args_process: }
-    \cs_if_exist_use:N \conditionally@traceon
-    \exp_after:wN \l_@@_fn_code_tl \l_@@_args_tl
-  }
-%    \end{macrocode}
-% \end{macro}
+% In older releases, the prefix was |xparse|, but since the 2021 Spring
+% release of \LaTeXe, the core code is included in the kernel, and this
+% file only holds the deprecated argument specifiers |G|, |l|, and |u|.
+% To match the prefix in the \LaTeXe{} kernel, so that the deprecated
+% types work if |xparse.sty| is loaded, the prefix has changed to |cmd|.
 %
-% \begin{macro}{\@@_defaults:}
-% \begin{macro}{\@@_defaults_def:, \@@_defaults_def:nn, \@@_defaults_def:nnn}
-% \begin{macro}{\@@_defaults_aux:,  \@@_defaults_error:w}
-%   First construct \cs{@@_tmp:w} (see below) that will receive
-%   the arguments found so far and determine default values for any
-%   missing argument.  Then call it repeatedly until the set of
-%   arguments stabilizes.  Since that could lead to an infinite loop we
-%   only call it up to nine times, the maximal number needed for
-%   stabilization if there is a chain of arguments that depend on each
-%   other.  If that fails to stabilize raise an error.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_defaults:
-  {
-    \@@_defaults_def:
-    \tl_set_eq:NN \l_@@_args_i_tl \l_@@_args_tl
-    \@@_defaults_aux: \@@_defaults_aux: \@@_defaults_aux:
-    \@@_defaults_aux: \@@_defaults_aux: \@@_defaults_aux:
-    \@@_defaults_aux: \@@_defaults_aux: \@@_defaults_aux:
-    \@@_defaults_error:w
-    \q_recursion_stop
-    \tl_set_eq:NN \l_@@_args_tl \l_@@_args_i_tl
-  }
-\cs_new_protected:Npn \@@_defaults_aux:
-  {
-    \tl_set:Nx \l_@@_args_ii_tl
-      { \exp_after:wN \@@_tmp:w \l_@@_args_i_tl }
-    \tl_if_eq:NNT \l_@@_args_ii_tl \l_@@_args_i_tl
-      { \use_none_delimit_by_q_recursion_stop:w }
-    \tl_set_eq:NN \l_@@_args_i_tl \l_@@_args_ii_tl
-  }
-\cs_new_protected:Npn \@@_defaults_error:w \q_recursion_stop
-  {
-    \__kernel_msg_error:nnx { xparse } { loop-in-defaults }
-      { \@@_environment_or_command: }
-  }
-%    \end{macrocode}
-%   To construct \cs{@@_tmp:w}, first go through the arguments
-%   found and the corresponding defaults, building a token list with
-%   |{#|\meta{arg number}|}| for arguments found in the input (whose
-%   default will not be used) and otherwise
-%   |{|\cs{exp_not:n}\Arg{default}|}| for arguments whose default will
-%   be used.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_defaults_def:
-  {
-    \tl_clear:N \l_@@_tmpa_tl
-    \int_zero:N \l_@@_current_arg_int
-    \@@_tl_mapthread_function:NNN \l_@@_args_tl \l_@@_defaults_tl
-      \@@_defaults_def:nn
-    \cs_generate_from_arg_count:NNVo \@@_tmp:w \cs_set:Npn
-      \l_@@_current_arg_int \l_@@_tmpa_tl
-  }
-\cs_generate_variant:Nn \cs_generate_from_arg_count:NNnn { NNVo }
-\cs_new_protected:Npn \@@_defaults_def:nn
-  {
-    \int_incr:N \l_@@_current_arg_int
-    \exp_args:NV \@@_defaults_def:nnn \l_@@_current_arg_int
-  }
-\cs_new_protected:Npn \@@_defaults_def:nnn #1#2#3
-  {
-    \tl_put_right:Nx \l_@@_tmpa_tl
-      {
-        {
-          \exp_not:N \exp_not:n
-            {
-              \tl_if_novalue:nTF {#2}
-                { \exp_not:o {#3} }
-                { \exp_not:n { ## #1 } }
-            }
-        }
-      }
-  }
+%<*package>
 %    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
 %
-% \begin{macro}{\@@_args_process:}
-% \begin{macro}{\@@_args_process_loop:nn, \@@_args_process_aux:n}
-%   Loop through arguments (stored in \cs{l_@@_args_tl}) and the
-%   corresponding processors (in \cs{l_@@_process_all_tl})
-%   simultaneously, apply all processors for each argument and store the
-%   result back into \cs{l_@@_args_tl}.  To allow processors to depend
-%   on other arguments, for every processor define a temporary auxiliary
-%   that receives all arguments \cs{l_@@_args_tl}.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_args_process:
-  {
-    \tl_clear:N \l_@@_args_ii_tl
-    \@@_tl_mapthread_function:NNN
-      \l_@@_args_tl
-      \l_@@_process_all_tl
-      \@@_args_process_loop:nn
-    \tl_set_eq:NN \l_@@_args_tl \l_@@_args_ii_tl
-  }
-\cs_new_protected:Npn \@@_args_process_loop:nn #1#2
-  {
-    \tl_set:Nn \ProcessedArgument {#1}
-    \tl_if_novalue:nF {#1}
-      { \tl_map_function:nN {#2} \@@_args_process_aux:n }
-    \tl_put_right:No \l_@@_args_ii_tl
-      { \exp_after:wN { \ProcessedArgument } }
-  }
-\cs_new_protected:Npn \@@_args_process_aux:n #1
-  {
-    \cs_generate_from_arg_count:NNnn \@@_tmp:w \cs_set:Npn
-      { \tl_count:N \l_@@_args_tl } {#1}
-    \exp_args:NNNo \exp_after:wN \@@_tmp:w \l_@@_args_tl
-      { \ProcessedArgument }
-  }
+\ProvidesExplPackage{xparse}{2021-02-02}{}
+  {L3 Experimental document command parser}
 %    \end{macrocode}
-% \end{macro}
-% \end{macro}
 %
-% \begin{macro}[EXP]{\@@_start_expandable:nNNNNn}
-%   This is called for all expandable commands.  |#6| is the signature,
-%   responsible for grabbing arguments.  |#5| is used to determine
-%   default values (or is |?| if there are none).  |#4| is the code to run.
-%   |#2|~and~|#3| are functions (named after the command) that grab a single
-%   argument in the input stream (|#3|~is~short).  The argument specification |#1| is
-%   only used by diagnostic functions.
-%    \begin{macrocode}
-\cs_new:Npn \@@_start_expandable:nNNNNn #1#2#3#4#5#6
-  { #6 \@@_end_expandable:NNw #5 #4 \q_@@ #2#3 }
-%    \end{macrocode}
-% \end{macro}
+% \subsection{Package options}
 %
-% \begin{macro}[EXP]{\@@_end_expandable:NNw}
-% \begin{macro}[EXP]{\@@_end_expandable_aux:w}
-% \begin{macro}[EXP]{\@@_end_expandable_aux:nNNNN}
-% \begin{macro}[EXP]{\@@_end_expandable_defaults:nnnNNn}
-% \begin{macro}[EXP]{\@@_end_expandable_defaults:nnw}
-% \begin{macro}[EXP]{\@@_end_expandable_defaults:nw}
-%   Followed by a function |#1| to determine default values (or |?| if
-%   there are no defaults), the code
-%   |#2|, arguments that have been grabbed, then \cs{q_@@} and two generic
-%   grabbers.  The idea to find default values is similar to the
-%   non-expandable case but we cannot define an auxiliary function, so
-%   at every step in the loop we need to go through all arguments
-%   searching for which ones started out as |-NoValue-| and replacing
-%   these by the newly computed values.  In fact we need to keep track
-%   of three versions of all arguments: the original version, the
-%   previous version with default values, and the currently built
-%   version (first argument of \cs{@@_end_expandable_defaults:nnnNNn}).
+% \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}
-\cs_new:Npn \@@_end_expandable:NNw #1#2
-  { \@@_end_expandable_aux:w #1#2 \prg_do_nothing: }
-\cs_new:Npn \@@_end_expandable_aux:w #1#2#3 \q_@@
-  { \exp_args:No \@@_end_expandable_aux:nNNNN {#3} #1 #2 }
-\cs_new:Npn \@@_end_expandable_aux:nNNNN #1#2#3#4#5
-  {
-    \token_if_eq_charcode:NNT ? #2 { \exp_after:wN \use_iv:nnnn }
-    \@@_end_expandable_defaults:nnnNNn {#1} { } {#1} #2#3
-      { } { } { } { } { } { } { } { } { } { }
-      {
-        \__kernel_msg_expandable_error:nnf
-          { xparse } { loop-in-defaults }
-          { \exp_args:Nf \tl_trim_spaces:n { \token_to_str:N #4 } }
-        \use_iv:nnnn
-      }
-    \q_stop
-  }
-\cs_new:Npn \@@_end_expandable_defaults:nnnNNn #1#2#3#4#5#6
-  {
-    #6
-    \str_if_eq:nnTF {#1} {#2}
-      { \use_i_delimit_by_q_stop:nw { #5 #1 } }
-      {
-        \exp_args:No \@@_tl_mapthread_function:nnN
-          { #4 #1 } {#3}
-          \@@_end_expandable_defaults:nnw
-        \@@_end_expandable_defaults:nnnNNn { } {#1} {#3} #4 #5
-      }
-  }
-\cs_new:Npn \@@_end_expandable_defaults:nnw #1#2
+\clist_new:N \l_@@_options_clist
+\DeclareOption* { \clist_put_right:NV \l_@@_options_clist \CurrentOption }
+\ProcessOptions \relax
+\keys_define:nn { ltcmd }
   {
-    \tl_if_novalue:nTF {#2}
-      { \exp_args:No \@@_end_expandable_defaults:nw {#1} }
-      { \@@_end_expandable_defaults:nw {#2} }
+    log-declarations .bool_set:N = \l_@@_log_bool ,
+    log-declarations .initial:n  = false
   }
-\cs_new:Npn \@@_end_expandable_defaults:nw
-    #1#2 \@@_end_expandable_defaults:nnnNNn #3
-  { #2 \@@_end_expandable_defaults:nnnNNn { #3 {#1} } }
+\keys_set:nV { ltcmd } \l_@@_options_clist
+\bool_if:NF \l_@@_log_bool
+  { \msg_redirect_module:nnn { LaTeX / ltcmd } { info } { none } }
 %    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
+% \end{variable}
+% \end{variable}
 %
 % \subsection{Normalizing the argument specifications}
 %
-% The goal here is to expand aliases and check that the argument
-% specification is valid before the main parsing run.  If it is not
-% valid the entire set up is abandoned to avoid any strange internal
-% errors.  A function is provided for each argument type that will grab
-% any extra data items and call the loop function after performing the
-% following checks and tasks.
-% \begin{itemize}
-%   \item Check that each argument has the correct number of data items
-%     associated with it, and that where a single character is required,
-%     one has actually been supplied.
-%   \item Check that processors and the markers~|+| and~|!| are followed
-%     by an argument for which they make sense, and are not redundant.
-%   \item Check the absence of forbidden types for expandable commands,
-%     namely \texttt{G}/\texttt{v} always, and \texttt{l}/\texttt{u}
-%     after optional arguments (\pkg{xparse} may have inserted braces
-%     due to a failed search for an optional argument).
-%   \item Check that no optional argument is followed by a mandatory
-%     argument with the same delimiter, as otherwise the optional
-%     argument could never be omitted.
-%   \item Keep track in \cs{l_@@_some_long_bool} and
-%     \cs{l_@@_some_short_bool} of whether the command has some
-%     long/short arguments.
-%   \item Keep track in \cs{l_@@_grab_expandably_bool} of whether all
-%     arguments are \texttt{m}/\texttt{l}/\texttt{u} type and short
-%     arguments appear before long ones, in which case they can be
-%     grabbed expandably just as safely as they could be grabbed
-%     nonexpandably.  Regardless of that, arguments of expandable
-%     commands will be grabbed expandably and arguments of environments
-%     will not (because the list of arguments built by non-expandable
-%     grabbing is used to pass them to the end-environment code).
-% \end{itemize}
-% Further checks happen at the end of the loop:
-% \begin{itemize}
-% \item that there are at most $9$ arguments;
-% \item that an expandable command does not end with an optional
-%   argument (this case is detected by using the fact that
-%   \cs{l_@@_last_delimiters_tl} is cleared by every mandatory argument
-%   and filled by every optional argument).
-% \end{itemize}
-%
-% \begin{macro}{\@@_normalize_arg_spec:n}
 % \begin{macro}{\@@_normalize_arg_spec_loop:n}
 %   Loop through the argument specification, calling an auxiliary
 %   specific to each argument type.  If any argument is unknown stop the
 %   definition.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_normalize_arg_spec:n #1
-  {
-    \int_zero:N \l_@@_current_arg_int
-    \tl_clear:N \l_@@_last_delimiters_tl
-    \tl_clear:N \l_@@_arg_spec_tl
-    \bool_set_true:N \l_@@_grab_expandably_bool
-    \bool_set_false:N \l_@@_obey_spaces_bool
-    \bool_set_false:N \l_@@_long_bool
-    \bool_set_false:N \l_@@_some_obey_spaces_bool
-    \bool_set_false:N \l_@@_some_long_bool
-    \bool_set_false:N \l_@@_some_short_bool
-    \@@_normalize_arg_spec_loop:n #1
-      \q_recursion_tail \q_recursion_tail \q_recursion_tail \q_recursion_stop
-    \int_compare:nNnT \l_@@_current_arg_int > 9
-      {
-        \__kernel_msg_error:nnxx { xparse } { too-many-arguments }
-          { \@@_environment_or_command: } { \tl_to_str:n {#1} }
-        \@@_bad_def:wn
-      }
-    \bool_if:NT \l_@@_expandable_bool
-      {
-        \tl_if_empty:NF \l_@@_last_delimiters_tl
-          {
-            \__kernel_msg_error:nnxx { xparse } { expandable-ending-optional }
-              { \iow_char:N \\ \l_@@_function_tl } { \tl_to_str:n {#1} }
-            \@@_bad_def:wn
-          }
-      }
-    \bool_if:NT \l_@@_expandable_bool
-      { \bool_set_true:N \l_@@_grab_expandably_bool }
-    \bool_if:NT \l_@@_environment_bool
-      { \bool_set_false:N \l_@@_grab_expandably_bool }
-  }
-\cs_new_protected:Npn \@@_normalize_arg_spec_loop:n #1
-  {
-    \quark_if_recursion_tail_stop:n {#1}
-    \int_incr:N \l_@@_current_arg_int
-    \cs_if_exist_use:cF { @@_normalize_type_ \tl_to_str:n {#1} :w }
-      {
-        \bool_lazy_any:nTF
-          {
-            { \str_if_eq_p:nn {#1} { G } }
-            { \str_if_eq_p:nn {#1} { g } }
-            { \str_if_eq_p:nn {#1} { l } }
-            { \str_if_eq_p:nn {#1} { u } }
-          }
-          {
-            \__kernel_msg_error:nnxx { xparse } { xparse-argument-type }
-              { \@@_environment_or_command: } { \tl_to_str:n {#1} }
-          }
-          {
-            \__kernel_msg_error:nnxx { xparse } { unknown-argument-type }
-              { \@@_environment_or_command: } { \tl_to_str:n {#1} }
-          }
-        \@@_bad_def:wn
-      }
-  }
-%</core>
-%<*package>
 \cs_gset_protected:Npn \@@_normalize_arg_spec_loop:n #1
   {
     \quark_if_recursion_tail_stop:n {#1}
     \int_incr:N \l_@@_current_arg_int
     \cs_if_exist_use:cF { @@_normalize_type_ \tl_to_str:n {#1} :w }
       {
-        \__kernel_msg_error:nnxx { xparse } { unknown-argument-type }
+        \__kernel_msg_error:nnxx { ltcmd } { unknown-argument-type }
           { \@@_environment_or_command: } { \tl_to_str:n {#1} }
         \@@_bad_def:wn
       }
   }
-%</package>
-%<*core>
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
 %
-% \begin{macro}
-%   {
-%     \@@_normalize_type_d:w,
-%     \@@_normalize_type_e:w,
-%     \@@_normalize_type_g:w,
-%     \@@_normalize_type_o:w,
-%     \@@_normalize_type_O:w,
-%     \@@_normalize_type_r:w,
-%     \@@_normalize_type_s:w,
-%   }
+% \begin{macro}{\@@_normalize_type_g:w}
 %   These argument types are aliases of more general ones, for example
-%   with the default argument |-NoValue-|.  To easily insert that marker
-%   expanded in the definitions we call \cs{@@_tmp:w} with the argument
-%   |-NoValue-|.  For argument types that need additional data, check
-%   that the data is present (not \cs{q_recursion_tail}) before
-%   proceeding.
+%   with the default argument |-NoValue-|.
 %    \begin{macrocode}
-\cs_set_protected:Npn \@@_tmp:w #1
-  {
-    \cs_new_protected:Npn \@@_normalize_type_d:w ##1##2
-      {
-        \quark_if_recursion_tail_stop_do:nn {##2} { \@@_bad_arg_spec:wn }
-        \@@_normalize_type_D:w {##1} {##2} {#1}
-      }
-    \cs_new_protected:Npn \@@_normalize_type_e:w ##1
-      {
-        \quark_if_recursion_tail_stop_do:nn {##1} { \@@_bad_arg_spec:wn }
-        \@@_normalize_type_E:w {##1} { }
-      }
-    \cs_new_protected:Npn \@@_normalize_type_o:w
-      { \@@_normalize_type_D:w [ ] {#1} }
-    \cs_new_protected:Npn \@@_normalize_type_O:w
-      { \@@_normalize_type_D:w [ ] }
-    \cs_new_protected:Npn \@@_normalize_type_r:w ##1##2
-      {
-        \quark_if_recursion_tail_stop_do:nn {##2} { \@@_bad_arg_spec:wn }
-        \@@_normalize_type_R:w {##1} {##2} {#1}
-      }
-    \cs_new_protected:Npn \@@_normalize_type_s:w
-      { \@@_normalize_type_t:w * }
-  }
-\exp_args:No \@@_tmp:w { \c_novalue_tl }
-%</core>
-%<*package>
 \cs_new_protected:Npx \@@_normalize_type_g:w
   { \exp_not:N \@@_normalize_type_G:w { \exp_not:V \c_novalue_tl } }
-%</package>
-%<*core>
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}
-%   {
-%     \@@_normalize_type_>:w,
-%     \@@_normalize_type_+:w,
-%     \@@_normalize_type_!:w,
-%   }
-%   Check that these prefixes have arguments, namely that the next token
-%   is not \cs{q_recursion_tail}, and remember to leave it after the
-%   looping macro.  Processors are forbidden in expandable commands.
-%   If all is good, store the prefix in the cleaned up
-%   \cs{l_@@_arg_spec_tl}, and decrement the argument number as prefixes
-%   do not correspond to arguments.
-%    \begin{macrocode}
-\cs_new_protected:cpn { @@_normalize_type_>:w } #1#2
-  {
-    \quark_if_recursion_tail_stop_do:nn {#2} { \@@_bad_arg_spec:wn }
-    \bool_if:NT \l_@@_expandable_bool
-      {
-        \__kernel_msg_error:nnxx { xparse } { processor-in-expandable }
-          { \iow_char:N \\ \l_@@_function_tl } { \tl_to_str:n {#1} }
-        \@@_bad_def:wn
-      }
-    \tl_put_right:Nx \l_@@_arg_spec_tl { > { \tl_trim_spaces:n {#1} } }
-    \int_decr:N \l_@@_current_arg_int
-    \bool_set_false:N \l_@@_grab_expandably_bool
-    \@@_normalize_arg_spec_loop:n {#2}
-  }
-\cs_new_protected:cpn { @@_normalize_type_+:w } #1
-  {
-    \quark_if_recursion_tail_stop_do:nn {#1} { \@@_bad_arg_spec:wn }
-    \bool_if:NT \l_@@_long_bool
-      {
-        \__kernel_msg_error:nnxx { xparse } { two-markers }
-          { \@@_environment_or_command: } { + }
-        \@@_bad_def:wn
-      }
-    \bool_set_true:N \l_@@_long_bool
-    \int_decr:N \l_@@_current_arg_int
-    \@@_normalize_arg_spec_loop:n {#1}
-  }
-\cs_new_protected:cpn { @@_normalize_type_!:w } #1
-  {
-    \quark_if_recursion_tail_stop_do:nn {#1} { \@@_bad_arg_spec:wn }
-    \bool_if:NT \l_@@_obey_spaces_bool
-      {
-        \__kernel_msg_error:nnxx { xparse } { two-markers }
-          { \@@_environment_or_command: } { ! }
-        \@@_bad_def:wn
-      }
-    \bool_set_true:N \l_@@_obey_spaces_bool
-    \bool_set_true:N \l_@@_some_obey_spaces_bool
-    \int_decr:N \l_@@_current_arg_int
-    \@@_normalize_arg_spec_loop:n {#1}
-  }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}
-%   {
-%     \@@_normalize_type_D:w,
-%     \@@_normalize_type_E:w,
-%     \@@_normalize_type_G:w,
-%     \@@_normalize_type_t:w,
-%   }
-% \begin{macro}{\@@_normalize_E_unique_check:w}
+% \begin{macro}{\@@_normalize_type_G:w}
 %   Optional argument types.  Check that all required data is present
 %   (and consists of single characters if applicable) and check for
-%   forbidden types for expandable commands.  For \texttt{E}-type
-%   require that there is at least one embellishment, that each one is a
-%   single character, and that there aren't more optional arguments than
-%   embellishments; also remember that each embellishment counts as one
-%   argument for \cs{l_@@_current_arg_int}.  Then in each case
+%   forbidden types for expandable commands.  Then in each case
 %   store the data in \cs{l_@@_arg_spec_tl}, and
 %   for later checks store in \cs{l_@@_last_delimiters_tl} the tokens
 %   whose presence determines whether there is an optional argument (for
 %   braces store |{}|, seen later as an empty delimiter).
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_normalize_type_D:w #1#2#3
-  {
-    \quark_if_recursion_tail_stop_do:nn {#3} { \@@_bad_arg_spec:wn }
-    \@@_single_token_check:n {#1} \@@_allowed_token_check:N #1
-    \@@_single_token_check:n {#2}
-    \@@_add_arg_spec:n { D #1 #2 {#3} }
-    \tl_put_right:Nn \l_@@_last_delimiters_tl {#1}
-    \bool_set_false:N \l_@@_grab_expandably_bool
-    \@@_normalize_arg_spec_loop:n
-  }
-\cs_new_protected:Npn \@@_normalize_type_E:w #1#2
-  {
-    \quark_if_recursion_tail_stop_do:nn {#2} { \@@_bad_arg_spec:wn }
-    \tl_if_blank:nT {#1} { \@@_bad_arg_spec:wn }
-    \tl_map_function:nN {#1} \@@_single_token_check:n
-    \tl_map_function:nN {#1} \@@_allowed_token_check:N
-    \@@_normalize_E_unique_check:w #1 \q_nil \q_stop
-    \int_compare:nNnT { \tl_count:n {#2} } > { \tl_count:n {#1} }
-      { \@@_bad_arg_spec:wn }
-    \@@_add_arg_spec:n { E {#1} {#2} }
-    \tl_put_right:Nn \l_@@_last_delimiters_tl {#1}
-    \bool_set_false:N \l_@@_grab_expandably_bool
-    \int_add:Nn \l_@@_current_arg_int { \tl_count:n {#1} - 1 }
-    \@@_normalize_arg_spec_loop:n
-  }
-\cs_new_protected:Npn \@@_normalize_E_unique_check:w #1#2 \q_stop
-  {
-    \quark_if_nil:NF #1
-      {
-        \tl_if_in:nnT {#2} {#1} { \@@_bad_arg_spec:wn }
-        \@@_normalize_E_unique_check:w #2 \q_stop
-      }
-  }
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_normalize_type_G:w #1
   {
     \quark_if_recursion_tail_stop_do:nn {#1} { \@@_bad_arg_spec:wn }
@@ -2079,72 +1131,22 @@
     \tl_put_right:Nn \l_@@_last_delimiters_tl { { } }
     \@@_normalize_arg_spec_loop:n
   }
-%</package>
-%<*core>
-\cs_new_protected:Npn \@@_normalize_type_t:w #1
-  {
-    \quark_if_recursion_tail_stop_do:Nn #1 { \@@_bad_arg_spec:wn }
-    \@@_single_token_check:n {#1} \@@_allowed_token_check:N #1
-    \tl_put_right:Nx \l_@@_arg_spec_tl
-      {
-        \bool_if:NT \l_@@_obey_spaces_bool { ! }
-        t \exp_not:n {#1}
-      }
-    \tl_put_right:Nn \l_@@_last_delimiters_tl {#1}
-    \bool_set_false:N \l_@@_grab_expandably_bool
-    \bool_set_false:N \l_@@_obey_spaces_bool
-    \bool_set_false:N \l_@@_long_bool
-    \@@_normalize_arg_spec_loop:n
-  }
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
 %
-% \begin{macro}
-%   {
-%     \@@_normalize_type_l:w,
-%     \@@_normalize_type_m:w,
-%     \@@_normalize_type_R:w,
-%     \@@_normalize_type_u:w
-%     \@@_normalize_type_v:w
-%   }
+% \begin{macro}{\@@_normalize_type_l:w,\@@_normalize_type_u:w}
 %   Mandatory arguments.  First check the required data is present,
 %   consists of single characters where applicable, and that the argument
-%   type is allowed for expandable commands if applicable.  For the
-%   \texttt{m} and \texttt{R} argument types check that they do not
-%   follow some optional argument with that delimiter as otherwise the
-%   optional argument could not be omitted.  Then save data in
+%   type is allowed for expandable commands if applicable.  Then save data in
 %   \cs{l_@@_arg_spec_tl}, count the mandatory argument, and empty the
 %   list of last delimiters.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_normalize_type_l:w
   {
     \@@_normalize_check_lu:N l
     \@@_add_arg_spec_mandatory:n { l }
     \@@_normalize_arg_spec_loop:n
   }
-%</package>
-%<*core>
-\cs_new_protected:Npn \@@_normalize_type_m:w
-  {
-    \@@_delimiter_check:nnn { } { m } { \iow_char:N \{ }
-    \@@_add_arg_spec_mandatory:n { m }
-    \@@_normalize_arg_spec_loop:n
-  }
-\cs_new_protected:Npn \@@_normalize_type_R:w #1#2#3
-  {
-    \quark_if_recursion_tail_stop_do:nn {#3} { \@@_bad_arg_spec:wn }
-    \@@_single_token_check:n {#1} \@@_allowed_token_check:N #1
-    \@@_single_token_check:n {#2}
-    \@@_delimiter_check:nnn {#1} { R/r } { \tl_to_str:n {#1} }
-    \bool_set_false:N \l_@@_grab_expandably_bool
-    \@@_add_arg_spec_mandatory:n { R #1 #2 {#3} }
-    \@@_normalize_arg_spec_loop:n
-  }
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_normalize_type_u:w #1
   {
     \quark_if_recursion_tail_stop_do:nn {#1} { \@@_bad_arg_spec:wn }
@@ -2152,368 +1154,15 @@
     \@@_add_arg_spec_mandatory:n { u {#1} }
     \@@_normalize_arg_spec_loop:n
   }
-%</package>
-%<*core>
-\cs_new_protected:Npn \@@_normalize_type_v:w
-  {
-    \@@_normalize_check_gv:N v
-    \@@_add_arg_spec_mandatory:n { v }
-    \@@_normalize_arg_spec_loop:n
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_normalize_type_b:w}
-%   This argument type is not allowed for commands.  This is only
-%   allowed at the end of the argument specification, hence we check
-%   that |#1| is the end.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_normalize_type_b:w #1
-  {
-    \bool_if:NF \l_@@_environment_bool
-      {
-        \__kernel_msg_error:nnxx
-          { xparse } { invalid-command-arg }
-          { \@@_environment_or_command: } { b }
-        \@@_bad_def:wn
-      }
-    \tl_clear:N \l_@@_last_delimiters_tl
-    \@@_add_arg_spec:n { b }
-    \quark_if_recursion_tail_stop:n {#1}
-    \__kernel_msg_error:nnxx { xparse } { arg-after-body }
-      { \@@_environment_or_command: }
-      { \tl_to_str:n {#1} }
-    \@@_bad_def:wn
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_single_token_check:n}
-%   Checks that the argument is a single (non-space) token (possibly
-%   surrounded by spaces), and aborts the definition otherwise.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_single_token_check:n #1
-  {
-    \tl_trim_spaces_apply:nN {#1} \tl_if_single_token:nF
-      {
-        \__kernel_msg_error:nnxx { xparse } { not-single-token }
-          { \@@_environment_or_command: } { \tl_to_str:n {#1} }
-        \@@_bad_def:wn
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_allowed_token_check:N}
-%   Some tokens are now allowed as delimiters for some argument types,
-%   notably implicit begin/end-group tokens (|\bgroup|/|\egroup|).
-%   The major problem with these tokens is that for |\peek_...| functions,
-%   a literal~|{|$_1$. is virtually indistinguishable from a |\bgroup| or
-%   other token which was |\let| to a~|{|$_1$, and the same goes
-%   for~|}|$_2$.  All other tokens can be easily distingushed from their
-%   implicit counterparts by grabbing them and looking at the string
-%   length (see \cs{@@_token_if_cs:NTF}), but for begin/end group tokens
-%   that is not possible without the risk of mistakenly grabbing the
-%   entire brace group (potentially leading to a~\texttt{!~Runaway argument}
-%   error) or trying to grab a |}|$_2$, leading to a~\texttt{!~Argument
-%   of~\dots~has an extra~\}}.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_allowed_token_check:N #1
-  {
-    \token_if_eq_meaning:NNTF #1 \c_group_begin_token
-        { \use:n }
-        {
-          \token_if_eq_meaning:NNTF #1 \c_group_end_token
-            { \use:n }
-            { \use_none:n }
-        }
-      {
-        \__kernel_msg_error:nnxxx
-          { xparse } { forbidden-implicit-group-token }
-          { \@@_environment_or_command: } { \tl_to_str:n {#1} }
-          {
-            \token_if_eq_meaning:NNTF #1 \c_group_begin_token
-              { begin } { end }
-          }
-        \@@_bad_def:wn
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_normalize_check_gv:N, \@@_normalize_check_lu:N}
-%   Called for arguments that are always forbidden, or forbidden after
-%   an optional argument, for expandable commands.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_normalize_check_gv:N #1
-  {
-    \bool_if:NT \l_@@_expandable_bool
-      {
-        \__kernel_msg_error:nnxx
-          { xparse } { invalid-expandable-argument-type }
-          { \iow_char:N \\ \l_@@_function_tl } { \tl_to_str:n {#1} }
-        \@@_bad_def:wn
-      }
-    \bool_set_false:N \l_@@_grab_expandably_bool
-  }
-\cs_new_protected:Npn \@@_normalize_check_lu:N #1
-  {
-    \bool_if:NT \l_@@_expandable_bool
-      {
-        \tl_if_empty:NF \l_@@_last_delimiters_tl
-          {
-            \__kernel_msg_error:nnxx
-              { xparse } { invalid-after-optional-expandably }
-              { \iow_char:N \\ \l_@@_function_tl } { \tl_to_str:n {#1} }
-            \@@_bad_def:wn
-          }
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_delimiter_check:nnn}
-%   Called for \texttt{m} and \texttt{R} arguments.  Checks that the
-%   leading token does not coincide with the token denoting the presence
-%   of a previous optional argument.  Instead of dealing with braces for
-%   the \texttt{m}-type we use an empty delimiter to denote that case.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_delimiter_check:nnn #1#2#3
-  {
-    \tl_map_inline:Nn \l_@@_last_delimiters_tl
-      {
-        \tl_if_eq:nnT {##1} {#1}
-          {
-            \__kernel_msg_warning:nnxx { xparse } { optional-mandatory }
-              {#2} {#3}
-          }
-      }
-  }
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}{\@@_bad_arg_spec:wn, \@@_bad_def:wn}
-%   If the argument specification is wrong, this provides an escape from
-%   the entire definition process.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_bad_arg_spec:wn #1 \@@_break_point:n #2
-  {
-    \__kernel_msg_error:nnxx { xparse } { bad-arg-spec }
-      { \@@_environment_or_command: } { \tl_to_str:n {#2} }
-  }
-\cs_new_protected:Npn \@@_bad_def:wn #1 \@@_break_point:n #2 { }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_arg_spec:n, \@@_add_arg_spec_mandatory:n}
-%   When adding an argument to the argument specification, set the
-%   \texttt{some_long} or \texttt{some_short} booleans as appropriate
-%   and clear the booleans keeping track of |+| and |!| markers.
-%   Before that, test for a short argument following some long
-%   arguments: this is forbidden for expandable commands and prevents
-%   grabbing arguments expandably.
-%
-%   For mandatory arguments do some more work, in particular complain if
-%   they were preceeded by~|!|.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_arg_spec:n #1
-  {
-    \bool_lazy_and:nnT
-      { ! \l_@@_long_bool }
-      { \l_@@_some_long_bool }
-      {
-        \bool_if:NT \l_@@_expandable_bool
-          {
-            \__kernel_msg_error:nnx { xparse } { inconsistent-long }
-              { \iow_char:N \\ \l_@@_function_tl }
-            \@@_bad_def:wn
-          }
-        \bool_set_false:N \l_@@_grab_expandably_bool
-      }
-    \bool_if:NTF \l_@@_long_bool
-      { \bool_set_true:N \l_@@_some_long_bool }
-      { \bool_set_true:N \l_@@_some_short_bool }
-    \tl_put_right:Nx \l_@@_arg_spec_tl
-      {
-        \bool_if:NT \l_@@_long_bool { + }
-        \bool_if:NT \l_@@_obey_spaces_bool { ! }
-        \exp_not:n {#1}
-      }
-    \bool_set_false:N \l_@@_long_bool
-    \bool_set_false:N \l_@@_obey_spaces_bool
-  }
-\cs_new_protected:Npn \@@_add_arg_spec_mandatory:n #1
-  {
-    \bool_if:NT \l_@@_some_obey_spaces_bool
-      {
-        \__kernel_msg_error:nnxx { xparse } { non-trailing-obey-spaces }
-          { \@@_environment_or_command: } { \tl_to_str:n {#1} }
-        \@@_bad_def:wn
-      }
-    \tl_clear:N \l_@@_last_delimiters_tl
-    \@@_add_arg_spec:n {#1}
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsection{Preparing the signature: general mechanism}
-%
-% \begin{macro}{\@@_prepare_signature:n}
-% \begin{macro}{\@@_prepare_signature:N}
-% \begin{macro}{\@@_prepare_signature_bypass:N}
-%   Actually creating the signature uses the same loop approach as
-%   normalizing the signature. There are first a number of variables which need
-%   to be set to track what is going on. Many of these variables are unused
-%   when defining expandable commands.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_prepare_signature:n #1
-  {
-    \int_zero:N \l_@@_current_arg_int
-    \bool_set_false:N \l_@@_long_bool
-    \bool_set_false:N \l_@@_obey_spaces_bool
-    \int_zero:N \l_@@_m_args_int
-    \bool_set_false:N \l_@@_defaults_bool
-    \tl_clear:N \l_@@_defaults_tl
-    \tl_clear:N \l_@@_process_all_tl
-    \tl_clear:N \l_@@_process_one_tl
-    \bool_set_false:N \l_@@_process_some_bool
-    \tl_clear:N \l_@@_signature_tl
-    \@@_prepare_signature:N #1 \q_recursion_tail \q_recursion_stop
-    \bool_if:NF \l_@@_expandable_bool { \@@_flush_m_args: }
-  }
-%    \end{macrocode}
-%  The main looping function does not take an argument, but carries out the
-%  reset on the processor boolean. This is split off from the rest of the
-%  process so that when actually setting up processors the flag-reset can
-%  be bypassed.
-%
-%  For each known argument type there is an appropriate function to actually
-%  do the addition to the signature. These are separate for expandable and
-%  standard functions, as the approaches are different.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_prepare_signature:N
-  {
-    \bool_set_false:N \l_@@_prefixed_bool
-    \@@_prepare_signature_bypass:N
-  }
-\cs_new_protected:Npn \@@_prepare_signature_bypass:N #1
-  {
-    \quark_if_recursion_tail_stop:N #1
-    \use:c
-      {
-         @@_add
-         \bool_if:NT \l_@@_grab_expandably_bool { _expandable }
-         _type_  \token_to_str:N #1 :w
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
 % \subsection{Setting up a standard signature}
 %
-% Each argument-adding function appends to the signature a grabber (and
-% for some types, the delimiters or default value), except the one for
-% \texttt{m} arguments.  These are collected and added to the signature
-% all at once by \cs{@@_flush_m_args:}, called for every other argument
-% type.  All of the functions then call the loop function
-% \cs{@@_prepare_signature:N}.  Default values of arguments are
-% collected by \cs{@@_add_default:n} rather than being stored with the
-% argument; this function and \cs{@@_add_default:} are also responsible
-% for keeping track of \cs{l_@@_current_arg_int}.
-%
-% \begin{macro}{\@@_add_type_+:w}
-%   Making the next argument long means setting the flag. The \texttt{m}
-%   arguments are recorded here as
-%   this has to be done for every case where there is then a long argument.
-%    \begin{macrocode}
-\cs_new_protected:cpn { @@_add_type_+:w }
-  {
-    \@@_flush_m_args:
-    \bool_set_true:N \l_@@_long_bool
-    \bool_set_true:N \l_@@_prefixed_bool
-    \@@_prepare_signature_bypass:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_!:w}
-%   Much the same for controlling trailing optional arguments.
-%    \begin{macrocode}
-\cs_new_protected:cpn { @@_add_type_!:w }
-  {
-    \@@_flush_m_args:
-    \bool_set_true:N \l_@@_obey_spaces_bool
-    \bool_set_true:N \l_@@_prefixed_bool
-    \@@_prepare_signature_bypass:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_>:w}
-%   When a processor is found, the processor code is stored.  It will be
-%   used by \cs{@@_args_process:} once arguments are all found. Here too
-%   the loop calls \cs{@@_prepare_signature_bypass:N} rather than
-%   \cs{@@_prepare_signature:N} so that the flag is not reset.
-%    \begin{macrocode}
-\cs_new_protected:cpn { @@_add_type_>:w } #1
-  {
-    \@@_flush_m_args:
-    \bool_set_true:N \l_@@_prefixed_bool
-    \bool_set_true:N \l_@@_process_some_bool
-    \tl_put_left:Nn \l_@@_process_one_tl { {#1} }
-    \@@_prepare_signature_bypass:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_b:w}
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_b:w
-  {
-    \@@_flush_m_args:
-    \@@_add_default:
-    \@@_add_grabber:N b
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_D:w}
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_D:w #1#2#3
-  {
-    \@@_flush_m_args:
-    \@@_add_default:n {#3}
-    \@@_add_grabber:N D
-    \tl_put_right:Nn \l_@@_signature_tl { #1 #2 }
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_E:w}
-%   The \texttt{E}-type argument needs a special handling of default
-%   values.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_E:w #1#2
-  {
-    \@@_flush_m_args:
-    \@@_add_default_E:nn {#1} {#2}
-    \@@_add_grabber:N E
-    \tl_put_right:Nn \l_@@_signature_tl { {#1} }
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
 % \begin{macro}{\@@_add_type_G:w}
 %   For the \texttt{G} type, the grabber and the default are added to the
 %   signature.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_add_type_G:w #1
   {
     \@@_flush_m_args:
@@ -2535,56 +1184,6 @@
     \@@_add_grabber:N l
     \@@_prepare_signature:N
   }
-%</package>
-%<*core>
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_m:w}
-%   The \texttt{m} type is special as short arguments which are not
-%   post-processed are simply counted at this stage. Thus there is a check
-%   to see if either of these cases apply. If so, a one-argument grabber
-%   is added to the signature. On the other hand, if a standard short
-%   argument is required it is simply counted at this stage, to be
-%   added later using \cs{@@_flush_m_args:}.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_m:w
-  {
-    \@@_add_default:
-    \bool_if:NTF \l_@@_prefixed_bool
-      { \@@_add_grabber:N m }
-      { \int_incr:N \l_@@_m_args_int }
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_R:w}
-%   The \texttt{R}-type argument is very similar to the \texttt{D}-type.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_R:w #1#2#3
-  {
-    \@@_flush_m_args:
-    \@@_add_default:n {#3}
-    \@@_add_grabber:N R
-    \tl_put_right:Nn \l_@@_signature_tl { #1 #2 }
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_t:w}
-%   Setting up a \texttt{t} argument means collecting one token for the test,
-%   and adding it along with the grabber to the signature.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_t:w #1
-  {
-    \@@_flush_m_args:
-    \@@_add_default:
-    \@@_add_grabber:N t
-    \tl_put_right:Nn \l_@@_signature_tl {#1}
-    \@@_prepare_signature:N
-  }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -2592,8 +1191,6 @@
 %   At the set up stage, the \texttt{u} type argument is identical to the
 %   \texttt{G} type except for the name of the grabber function.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_add_type_u:w #1
   {
     \@@_flush_m_args:
@@ -2602,273 +1199,18 @@
     \tl_put_right:Nn \l_@@_signature_tl { {#1} }
     \@@_prepare_signature:N
   }
-%</package>
-%<*core>
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_type_v:w}
-%   At this stage, the \texttt{v} argument is identical to \texttt{l}
-%   except that since the grabber may fail to read a verbatim argument
-%   we need a default value.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_type_v:w
-  {
-    \@@_flush_m_args:
-    \exp_args:No \@@_add_default:n \c_novalue_tl
-    \@@_add_grabber:N v
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_flush_m_args:}
-%   As \texttt{m} arguments are simply counted, there is a need to add
-%   them to the token register in a block. As this function can only
-%   be called if something other than \texttt{m} turns up, the flag can
-%   be switched here.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_flush_m_args:
-  {
-    \int_compare:nNnT \l_@@_m_args_int > 0
-      {
-        \tl_put_right:Nx \l_@@_signature_tl
-          { \exp_not:c { @@_grab_m_ \int_use:N \l_@@_m_args_int :w } }
-        \tl_put_right:Nx \l_@@_process_all_tl
-          { \prg_replicate:nn { \l_@@_m_args_int } { { } } }
-      }
-    \int_zero:N \l_@@_m_args_int
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_grabber:N}
-%   To keep the various checks needed in one place, adding the grabber
-%   to the signature is done here.  The only questions are whether the
-%   grabber should be long or not, and whether to obey spaces.  The
-%   \cs{l_@@_obey_spaces_bool} boolean can only be \texttt{true} for
-%   trailing optional arguments.  In that case spaces will not be
-%   ignored when looking for that optional argument.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_grabber:N #1
-  {
-    \tl_put_right:Nx \l_@@_signature_tl
-      {
-        \exp_not:c
-          {
-            @@_grab_ #1
-            \bool_if:NT \l_@@_long_bool { _long }
-            \bool_if:NT \l_@@_obey_spaces_bool { _obey_spaces }
-            :w
-          }
-      }
-    \bool_set_false:N \l_@@_long_bool
-    \bool_set_false:N \l_@@_obey_spaces_bool
-    \tl_put_right:Nx \l_@@_process_all_tl
-      { { \exp_not:o \l_@@_process_one_tl } }
-    \tl_clear:N \l_@@_process_one_tl
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_default:n, \@@_add_default:, \@@_add_default_E:nn}
-%   Store the default value of an argument, or rather code that gives
-%   that default value (it may involve other arguments).  This is
-%   \cs{c_novalue_tl} for arguments with no actual default or with
-%   default |-NoValue-|; and (in a brace group) \cs{prg_do_nothing:}
-%   followed by a default value for others.  For \texttt{E}-type
-%   arguments, pad the defaults |#2| with some \cs{c_novalue_tl}
-%   until there are as many as embellishments~|#1|.  These functions are
-%   also used when defining expandable commands.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_default:n #1
-  {
-    \tl_if_novalue:nTF {#1}
-      { \@@_add_default: }
-      {
-        \int_incr:N \l_@@_current_arg_int
-        \bool_set_true:N \l_@@_defaults_bool
-        \tl_put_right:Nn \l_@@_defaults_tl { { \prg_do_nothing: #1 } }
-      }
-  }
-\cs_new_protected:Npn \@@_add_default:
-  {
-    \int_incr:N \l_@@_current_arg_int
-    \tl_put_right:Nn \l_@@_defaults_tl { \c_novalue_tl }
-  }
-\cs_new_protected:Npn \@@_add_default_E:nn #1#2
-  {
-    \tl_map_function:nN {#2} \@@_add_default:n
-    \prg_replicate:nn
-      { \tl_count:n {#1} - \tl_count:n {#2} }
-      { \@@_add_default: }
-  }
 %    \end{macrocode}
 % \end{macro}
 %
 % \subsection{Setting up expandable types}
 %
-% The approach here is not dissimilar to that for standard types, but fewer types
-% are supported. There is
-% also a need to define the per-function auxiliaries: this is done here, while
-% the general grabbers are dealt with later.
-%
-% \begin{macro}{\@@_add_expandable_type_+:w}
-%   We have already checked that short arguments are before long
-%   arguments, so \cs{l_@@_long_bool} only changes from \texttt{false}
-%   to \texttt{true} once (and there is no need to reset it after each
-%   argument).  Also knock back the argument count because |+| is not an
-%   argument.  Continue the loop.
-%    \begin{macrocode}
-\cs_new_protected:cpn { @@_add_expandable_type_+:w }
-  {
-    \bool_set_true:N \l_@@_long_bool
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_expandable_type_D:w}
-% \begin{macro}{\@@_add_expandable_type_D_aux:NNNn}
-% \begin{macro}{\@@_add_expandable_type_D_aux:NNN}
-% \begin{macro}{\@@_add_expandable_type_D_aux:NN}
-%   The set up for \texttt{D}-type arguments involves constructing a
-%   rather complex auxiliary which is used
-%   repeatedly when grabbing. There is an auxiliary here so that the
-%   \texttt{R}-type can share code readily: |#1| is |D| or~|R|.
-%   The |_aux:NN| auxiliary is needed if the two delimiting tokens are
-%   identical: in contrast to the non-expandable route, the grabber here
-%   has to act differently for this case.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_expandable_type_D:w
-  { \@@_add_expandable_type_D_aux:NNNn D }
-\cs_new_protected:Npn \@@_add_expandable_type_D_aux:NNNn #1#2#3#4
-  {
-    \@@_add_default:n {#4}
-    \tl_if_eq:nnTF {#2} {#3}
-      { \@@_add_expandable_type_D_aux:NN #1 #2 }
-      { \@@_add_expandable_type_D_aux:NNN #1 #2 #3 }
-    \@@_prepare_signature:N
-  }
-\cs_new_protected:Npn \@@_add_expandable_type_D_aux:NNN #1#2#3
-  {
-    \bool_if:NTF \l_@@_long_bool
-      { \cs_set:cpx }
-      { \cs_set_nopar:cpx }
-      { \l_@@_expandable_aux_name_tl } ##1 ##2 #2 ##3 \q_@@ ##4 #3
-      { ##1 {##2} {##3} {##4} }
-    \@@_add_expandable_grabber:nn {#1}
-      {
-        \exp_not:c  { \l_@@_expandable_aux_name_tl }
-        \exp_not:n { #2 #3 }
-      }
-  }
-\cs_new_protected:Npn \@@_add_expandable_type_D_aux:NN #1#2
-  {
-    \bool_if:NTF \l_@@_long_bool
-      { \cs_set:cpx }
-      { \cs_set_nopar:cpx }
-      { \l_@@_expandable_aux_name_tl } ##1 #2 ##2 #2
-      { ##1 {##2} }
-    \@@_add_expandable_grabber:nn { #1_alt }
-      {
-        \exp_not:c  { \l_@@_expandable_aux_name_tl }
-        \exp_not:n {#2}
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_expandable_type_E:w}
-% \begin{macro}{\@@_add_expandable_type_E_aux:n}
-%   For each embellishment, use \cs{@@_get_grabber:NN} to obtain an
-%   auxiliary delimited by that token and store a pair constituted of
-%   the auxiliary and the token in \cs{l_@@_tmpb_tl}, before appending
-%   the whole set of these pairs to the signature, and an equal number
-%   of |-NoValue-| markers (regardless of the default values of
-%   arguments).  Set the current argument appropriately.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_expandable_type_E:w #1#2
-  {
-    \@@_add_default_E:nn {#1} {#2}
-    \tl_clear:N \l_@@_tmpb_tl
-    \tl_map_function:nN {#1} \@@_add_expandable_type_E_aux:n
-    \@@_add_expandable_grabber:nn
-      { E \bool_if:NT \l_@@_long_bool { _long } }
-      {
-        { \exp_not:o \l_@@_tmpb_tl }
-        {
-          \prg_replicate:nn { \tl_count:n {#1} }
-            { { \c_novalue_tl } }
-        }
-      }
-    \@@_prepare_signature:N
-  }
-\cs_new_protected:Npn \@@_add_expandable_type_E_aux:n #1
-  {
-    \@@_get_grabber:NN #1 \l_@@_tmpa_tl
-    \tl_put_right:Nx \l_@@_tmpb_tl
-      { \exp_not:o \l_@@_tmpa_tl \exp_not:N #1 }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
 % \begin{macro}{\@@_add_expandable_type_l:w}
 %   Reuse type \texttt{u}, thanks to the fact that \TeX{} macros whose
 %   parameter text ends with |#| in fact end up being delimited by an
 %   open brace.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_add_expandable_type_l:w
   { \@@_add_expandable_type_u:w ## }
-%</package>
-%<*core>
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_expandable_type_m:w}
-%   Unlike the standard case, when working expandably each argument is always
-%   grabbed separately.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_expandable_type_m:w
-  {
-    \@@_add_default:
-    \@@_add_expandable_grabber:nn
-      { m \bool_if:NT \l_@@_long_bool { _long } } { }
-    \@@_prepare_signature:N
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_expandable_type_R:w}
-%   The \texttt{R}-type is very similar to the \texttt{D}-type
-%   argument, and so the same internals are used.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_expandable_type_R:w
-  { \@@_add_expandable_type_D_aux:NNNn R }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_expandable_type_t:w}
-%   An auxiliary delimited by |#1| is built now.  It will be used to
-%   test for the presence of that token.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_expandable_type_t:w #1
-  {
-    \@@_add_default:
-    \@@_get_grabber:NN #1 \l_@@_tmpa_tl
-    \@@_add_expandable_grabber:nn { t }
-      {
-        \exp_not:o \l_@@_tmpa_tl
-        \exp_not:N #1
-      }
-    \@@_prepare_signature:N
-  }
 %    \end{macrocode}
 % \end{macro}
 %
@@ -2876,8 +1218,6 @@
 %   Define an auxiliary that will be used directly in the signature.  It
 %   grabs one argument delimited by |#1| and places it before \cs{q_@@}.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_add_expandable_type_u:w #1
   {
     \@@_add_default:
@@ -2890,403 +1230,11 @@
       { \exp_not:c  { \l_@@_expandable_aux_name_tl } }
     \@@_prepare_signature:N
   }
-%</package>
-%<*core>
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_expandable_grabber:nn}
-%   This is called for all arguments to place the right grabber in the
-%   signature.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_expandable_grabber:nn #1#2
-  {
-    \tl_put_right:Nx \l_@@_signature_tl
-      { \exp_not:c { @@_expandable_grab_ #1 :w } #2 }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_get_grabber:NN}
-% \begin{macro}{\@@_get_grabber_auxi:NN}
-% \begin{macro}{\@@_get_grabber_auxii:NN}
-%   Given a token |#1|, defines an expandable function delimited by that
-%   token and stores it in the token list~|#2|.  The function is named
-%   after the token, unless that function name is already taken by some
-%   other grabber (this can happen in the rare case where delimiters
-%   with different category codes are used in the same document): in
-%   that case use a global counter to get a unique name.  Since the
-%   grabbers are not named after \pkg{xparse} commands they should not
-%   be used to get material from the input stream.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_get_grabber:NN #1#2
-  {
-    \cs_set:Npn \@@_tmp:w ##1 #1 {##1}
-    \exp_args:Nc \@@_get_grabber_auxi:NN
-      { @@_grabber_ \token_to_str:N #1 :w } #2
-  }
-\cs_new_protected:Npn \@@_get_grabber_auxi:NN #1#2
-  {
-    \cs_if_eq:NNTF \@@_tmp:w #1
-      { \tl_set:Nn #2 {#1} }
-      {
-        \cs_if_exist:NTF #1
-          {
-            \int_gincr:N \g_@@_grabber_int
-            \exp_args:Nc \@@_get_grabber_auxi:NN
-              {
-                @@_grabber_
-                - \int_use:N \g_@@_grabber_int :w
-              }
-              #2
-          }
-          { \@@_get_grabber_auxii:NN #1 #2 }
-      }
-  }
-\cs_new_protected:Npn \@@_get_grabber_auxii:NN #1#2
-  {
-    \cs_set_eq:NN #1 \@@_tmp:w
-    \tl_set:Nn #2 {#1}
-  }
 %    \end{macrocode}
 % \end{macro}
-% \end{macro}
-% \end{macro}
 %
 % \subsection{Grabbing arguments}
 %
-% All of the grabbers follow the same basic pattern. The initial
-% function stores in \cs{l_@@_signature_tl} the code to grab further
-% arguments, defines (the function in) \cs{l_@@_fn_tl} that will grab
-% the argument, and calls it.
-%
-% Defining \cs{l_@@_fn_tl} means determining whether to use
-% \cs{cs_set:Npn} or \cs{cs_set_nopar:Npn}, and for optional arguments
-% whether to skip spaces. Once the argument is found, \cs{l_@@_fn_tl}
-% calls \cs{@@_add_arg:n}, responsible for calling processors and
-% grabbing further arguments.
-%
-% \begin{macro}
-%   {
-%     \@@_grab_b:w,
-%     \@@_grab_b_long:w,
-%     \@@_grab_b_obey_spaces:w,
-%     \@@_grab_b_long_obey_spaces:w,
-%     \@@_grab_b_aux:NNw,
-%     \@@_grab_b_end:Nw
-%   }
-%   This uses the well-tested code of \texttt{D}-type arguments,
-%   skipping the peeking step because the \texttt{b}-type argument is
-%   always present, and adding a cleanup stage at the end by hijacking
-%   the signature.  The clean-up consists of properly
-%   dealing with \cs{l_@@_args_tl} and also putting back the \cs{end}
-%   that served as an end-delimiter: this \cs{end} receives the
-%   environment name as its argument and is run normally.  The
-%   \texttt{D}-type code stores the argument found (body of the
-%   environment) as a brace group in \cs{l_@@_args_tl} and depending on
-%   the presence of a prefix~|!| we trim spaces or not before adding
-%   this braced argument into the saved \cs{l_@@_args_tl}.
-%   The strange \verb*|\begin | control sequence is there for display
-%     purposes only: it has to look like |\begin| in the terminal but
-%       not to delimited arguments.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_b:w
-  { \@@_grab_b_aux:NNw \cs_set_protected_nopar:Npn \tl_trim_spaces:n }
-\cs_new_protected:Npn \@@_grab_b_long:w
-  { \@@_grab_b_aux:NNw \cs_set_protected:Npn \tl_trim_spaces:n }
-\cs_new_protected:Npn \@@_grab_b_obey_spaces:w
-  { \@@_grab_b_aux:NNw \cs_set_protected_nopar:Npn \exp_not:n }
-\cs_new_protected:Npn \@@_grab_b_long_obey_spaces:w
-  { \@@_grab_b_aux:NNw \cs_set_protected:Npn \exp_not:n }
-\cs_new_protected:Npn \@@_grab_b_aux:NNw #1#2#3 \@@_run_code:
-  {
-    \@@_grab_D_aux:NNnN \begin \end {#3} #1
-    \tl_put_left:Nn \l_@@_signature_tl { \@@_grab_b_end:Nw #2 }
-    \tl_set_eq:NN \l_@@_saved_args_tl \l_@@_args_tl
-    \tl_clear:N \l_@@_args_tl
-    \exp_args:Nc \l_@@_fn_tl { begin ~ }
-  }
-\cs_new_protected:Npn \@@_grab_b_end:Nw #1#2 \@@_run_code:
-  {
-    \tl_set:Nx \l_@@_args_tl
-      {
-        \exp_not:V \l_@@_saved_args_tl
-        { \exp_after:wN #1 \l_@@_args_tl }
-      }
-    #2
-    \@@_run_code:
-    \end
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_D:w}
-% \begin{macro}{\@@_grab_D_long:w}
-% \begin{macro}{\@@_grab_D_obey_spaces:w}
-% \begin{macro}{\@@_grab_D_long_obey_spaces:w}
-%   The generic delimited argument grabber. The auxiliary function does
-%   a peek test before calling \cs{@@_grab_D_call:Nw}, so that the
-%   optional nature of the argument works as expected.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_D:w #1#2#3 \@@_run_code:
-  {
-    \@@_grab_D_aux:NNnNN #1 #2 {#3} \cs_set_protected_nopar:Npn
-      \@@_peek_nonspace_remove:NTF
-  }
-\cs_new_protected:Npn \@@_grab_D_long:w #1#2#3 \@@_run_code:
-  {
-    \@@_grab_D_aux:NNnNN #1 #2 {#3} \cs_set_protected:Npn
-      \@@_peek_nonspace_remove:NTF
-  }
-\cs_new_protected:Npn \@@_grab_D_obey_spaces:w #1#2#3 \@@_run_code:
-  {
-    \@@_grab_D_aux:NNnNN #1 #2 {#3} \cs_set_protected_nopar:Npn
-      \@@_peek_meaning_remove:NTF
-  }
-\cs_new_protected:Npn \@@_grab_D_long_obey_spaces:w #1#2#3 \@@_run_code:
-  {
-    \@@_grab_D_aux:NNnNN #1 #2 {#3} \cs_set_protected:Npn
-      \@@_peek_meaning_remove:NTF
-  }
-%    \end{macrocode}
-% \begin{macro}{\@@_grab_D_aux:NNnNN}
-% \begin{macro}{\@@_grab_D_aux:NNnN}
-%   This is a bit complicated. The idea is that, in order to check for
-%   nested optional argument tokens (\texttt{[[...]]} and so on) the
-%   argument needs to be grabbed without removing any braces at all. If
-%   this is not done, then cases like |[{[}]| fail. So after testing for
-%   an optional argument, it is collected piece-wise. Inserting a quark
-%   prevents loss of braces, and there is then a test to see if there are
-%   nested delimiters to handle.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_D_aux:NNnNN #1#2#3#4#5
-  {
-    \@@_grab_D_aux:NNnN #1#2 {#3} #4
-    #5 #1
-      { \@@_grab_D_call:Nw #1 }
-      { \@@_add_arg:o \c_novalue_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. Also notice that a \emph{blank} argument might still contain
-%   spaces.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_D_aux:NNnN #1#2#3#4
-  {
-    \tl_set:Nn \l_@@_signature_tl {#3}
-    \exp_after:wN #4 \l_@@_fn_tl ##1 #2
-      {
-        \tl_if_in:nnTF {##1} {#1}
-          { \@@_grab_D_nested:NNnN #1 #2 {##1} #4 }
-          {
-            \tl_if_blank:oTF { \use_none:n ##1 }
-              { \@@_add_arg:o { \use_none:n ##1 } }
-              {
-                \str_if_eq:eeTF
-                  { \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 } }
-              }
-          }
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \begin{macro}{\@@_grab_D_nested:NNnN}
-% \begin{macro}{\@@_grab_D_nested:w}
-% \begin{macro}{\l_@@_nesting_a_tl}
-% \begin{macro}{\l_@@_nesting_b_tl}
-% \begin{macro}{\q_@@}
-%   Catching nested optional arguments means more work. The aim here is
-%   to collect up each pair of optional tokens without \TeX{} helping out,
-%   and without counting anything. The code above will already have
-%   removed the leading opening token and a closing token, but the
-%   wrong one. The aim is then to work through the material grabbed
-%   so far and divide it up on each opening token, grabbing a closing
-%   token to match (thus working in pairs). Once there are no opening
-%   tokens, then there is a second check to see if there are any
-%   opening tokens in the second part of the argument (for things
-%   like |[][]|). Once everything has been found, the entire collected
-%   material is added to the output as a single argument. The only tricky part
-%   here is ensuring that any grabbing function that might run away is named
-%   after the function currently being parsed and not after \pkg{xparse}. That
-%   leads to some rather complex nesting! There is also a need to prevent the
-%   loss of any braces, hence the insertion and removal of quarks along the
-%   way.
-%    \begin{macrocode}
-\tl_new:N \l_@@_nesting_a_tl
-\tl_new:N \l_@@_nesting_b_tl
-\quark_new:N \q_@@
-\cs_new_protected:Npn \@@_grab_D_nested:NNnN #1#2#3#4
-  {
-    \tl_clear:N \l_@@_nesting_a_tl
-    \tl_clear:N \l_@@_nesting_b_tl
-    \exp_after:wN #4 \l_@@_fn_tl ##1 #1 ##2 \q_@@ ##3 #2
-      {
-        \tl_put_right:No \l_@@_nesting_a_tl { \use_none:n ##1 #1 }
-        \tl_put_right:No \l_@@_nesting_b_tl { \use_i:nn #2 ##3 }
-        \tl_if_in:nnTF {##2} {#1}
-          {
-            \l_@@_fn_tl
-              \q_nil ##2 \q_@@ \ERROR
-          }
-          {
-            \tl_put_right:Nx \l_@@_nesting_a_tl
-              { \@@_grab_D_nested:w \q_nil ##2 \q_stop }
-            \tl_if_in:NnTF \l_@@_nesting_b_tl {#1}
-              {
-                \tl_set_eq:NN \l_@@_tmpa_tl \l_@@_nesting_b_tl
-                \tl_clear:N \l_@@_nesting_b_tl
-                \exp_after:wN \l_@@_fn_tl \exp_after:wN
-                  \q_nil \l_@@_tmpa_tl \q_nil \q_@@ \ERROR
-              }
-              {
-                \tl_put_right:No \l_@@_nesting_a_tl
-                  \l_@@_nesting_b_tl
-                \@@_add_arg:V \l_@@_nesting_a_tl
-              }
-          }
-      }
-    \l_@@_fn_tl #3 \q_nil \q_@@ \ERROR
-  }
-\cs_new:Npn \@@_grab_D_nested:w #1 \q_nil \q_stop
-  { \exp_not:o { \use_none:n #1 } }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \begin{macro}{\@@_grab_D_call:Nw}
-%   For \texttt{D} and \texttt{R}-type arguments, to avoid losing any
-%   braces, a token needs to be inserted before the argument to be grabbed.
-%   If the argument runs away because the closing token is missing then this
-%   inserted token shows up in the terminal. Ideally, |#1| would therefore be
-%   used directly, but that is no good as it will mess up the rest of the
-%   grabber. Instead, a copy of |#1| with an altered category code is used,
-%   as this will look right in the terminal but will not mess up the grabber.
-%   The only issue then is that the category code of |#1| is unknown. So there
-%   is a quick test to ensure that the inserted token can never be matched by
-%   the grabber. (This assumes that the open and close delimiters are not the
-%   same character with different category codes, but that really should not
-%   happen in any sensible document-level syntax.)
-%   An exception is when |#1| is a control sequence token, in which case the
-%   character-token treatment is no good because if hit with \cs{token_to_str:N}
-%   it would add sputios tokens to the argument. In this case a different
-%   branch is taken. The token inserted is then the same \meta{csname} as |#1|,
-%   but with a space appended, so that the grabber don't see it as another
-%   of the same delimiter.
-%    \begin{macrocode}
-\cs_new_protected_nopar:Npn \@@_grab_D_call:Nw #1
-  {
-    \token_if_eq_catcode:NNTF + #1
-      {
-        \exp_after:wN \exp_after:wN \exp_after:wN
-          \l_@@_fn_tl \char_generate:nn { `#1 } { 11 }
-      }
-      {
-        \@@_token_if_cs:NTF #1
-          {
-            \exp_after:wN \l_@@_fn_tl
-            \cs:w \cs_to_str:N #1 ~ \cs_end:
-          }
-          {
-            \exp_after:wN \l_@@_fn_tl
-            \token_to_str:N #1
-          }
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}
-%   {
-%     \@@_grab_E:w, \@@_grab_E_long:w,
-%     \@@_grab_E_obey_spaces:w, \@@_grab_E_long_obey_spaces:w
-%   }
-% \begin{macro}{\@@_grab_E:nnNN}
-% \begin{macro}{\@@_grab_E_loop:NnN}
-% \begin{macro}{\@@_grab_E_finalise:}
-%   Everything here needs to point to a loop.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_E:w #1#2 \@@_run_code:
-  {
-    \@@_grab_E:nnNN {#1} {#2}
-      \cs_set_protected_nopar:Npn
-      \@@_peek_nonspace_remove:NTF
-  }
-\cs_new_protected:Npn \@@_grab_E_long:w #1#2 \@@_run_code:
-  {
-    \@@_grab_E:nnNN {#1} {#2}
-      \cs_set_protected:Npn
-      \@@_peek_nonspace_remove:NTF
-  }
-\cs_new_protected:Npn \@@_grab_E_obey_spaces:w #1#2 \@@_run_code:
-  {
-    \@@_grab_E:nnNN {#1} {#2}
-      \cs_set_protected_nopar:Npn
-      \@@_peek_meaning_remove:NTF
-  }
-\cs_new_protected:Npn \@@_grab_E_long_obey_spaces:w #1#2 \@@_run_code:
-  {
-    \@@_grab_E:nnNN {#1} {#2}
-      \cs_set_protected:Npn
-      \@@_peek_meaning_remove:NTF
-  }
-%    \end{macrocode}
-%   A loop is needed here to allow a random ordering of keys. These are
-%   searched for one at a time, with any not found needing to be tracked:
-%   they can appear later. The grabbed values are held in a property list
-%   which is then turned into an ordered list to be passed back to the user.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_E:nnNN #1#2#3#4
-  {
-    \exp_after:wN #3 \l_@@_fn_tl ##1##2##3
-      {
-        \prop_put:Nnn \l_@@_tmp_prop {##1} {##3}
-        \@@_grab_E_loop:NnN #4 { } ##2 \q_recursion_stop
-      }
-    \prop_clear:N \l_@@_tmp_prop
-    \tl_set:Nn \l_@@_signature_tl {#2}
-    \cs_set_protected:Npn \@@_grab_E_finalise:
-      {
-        \tl_map_inline:nn {#1}
-          {
-            \prop_get:NnNF \l_@@_tmp_prop {####1} \l_@@_tmpb_tl
-              { \tl_set_eq:NN \l_@@_tmpb_tl \c_novalue_tl }
-            \tl_put_right:Nx \l_@@_args_tl
-              { { \exp_not:V \l_@@_tmpb_tl } }
-          }
-        \l_@@_signature_tl \@@_run_code:
-      }
-    \@@_grab_E_loop:NnN #4 { } #1 \q_recursion_tail \q_recursion_stop
-  }
-\cs_new_protected:Npn \@@_grab_E_loop:NnN #1#2#3#4 \q_recursion_stop
-  {
-    \cs_if_eq:NNTF #3 \q_recursion_tail
-      { \@@_grab_E_finalise: }
-      {
-        #1 #3
-          { \l_@@_fn_tl #3 {#2#4} }
-          { \@@_grab_E_loop:NnN #1 {#2#3} #4 \q_recursion_stop }
-      }
-  }
-\cs_new_protected:Npn \@@_grab_E_finalise: { }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
 % \begin{macro}{\@@_grab_G:w}
 % \begin{macro}{\@@_grab_G_long:w}
 % \begin{macro}{\@@_grab_G_obey_spaces:w}
@@ -3295,8 +1243,6 @@
 %   Optional groups are checked by meaning, so that the same code will
 %   work with, for example, \ConTeXt{}-like input.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_grab_G:w #1 \@@_run_code:
   {
     \@@_grab_G_aux:nNN {#1} \cs_set_protected_nopar:Npn
@@ -3349,168 +1295,6 @@
       { \@@_add_arg:n {##1} }
     \l_@@_fn_tl
   }
-%</package>
-%<*core>
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_m:w}
-% \begin{macro}{\@@_grab_m_long:w}
-%   Collecting a single mandatory argument is quite easy.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_m:w #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_protected_nopar:Npn \l_@@_fn_tl ##1
-      { \@@_add_arg:n {##1} }
-    \l_@@_fn_tl
-  }
-\cs_new_protected:Npn \@@_grab_m_long:w #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_protected:Npn \l_@@_fn_tl ##1
-      { \@@_add_arg:n {##1} }
-    \l_@@_fn_tl
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_m_1:w}
-% \begin{macro}{\@@_grab_m_2:w}
-% \begin{macro}{\@@_grab_m_3:w}
-% \begin{macro}{\@@_grab_m_4:w}
-% \begin{macro}{\@@_grab_m_5:w}
-% \begin{macro}{\@@_grab_m_6:w}
-% \begin{macro}{\@@_grab_m_7:w}
-% \begin{macro}{\@@_grab_m_8:w}
-% \begin{macro}{\@@_grab_m_9:w}
-% \begin{macro}{\@@_grab_m_aux:Nnnnnnnnn}
-%   Grabbing 1--8 mandatory arguments is done by giving 8--1 known
-%   arguments to a 9-argument function that stores them in
-%   \cs{l_@@_args_tl}.  For simplicity, grabbing 9 mandatory arguments
-%   is done by grabbing 5 then 4 arguments.
-%    \begin{macrocode}
-\cs_new_protected_nopar:Npn \@@_grab_m_aux:Nnnnnnnnn #1#2#3#4#5#6#7#8#9
-  {
-    \tl_put_right:No \l_@@_args_tl
-      { #1 {#2} {#3} {#4} {#5} {#6} {#7} {#8} {#9} }
-    \l_@@_signature_tl \@@_run_code:
-  }
-\cs_new_protected:cpn { @@_grab_m_1:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:nnnnnnn { } { } { } { } { } { } { }
-  }
-\cs_new_protected:cpn { @@_grab_m_2:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:nnnnnn { } { } { } { } { } { }
-  }
-\cs_new_protected:cpn { @@_grab_m_3:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:nnnnn { } { } { } { } { }
-  }
-\cs_new_protected:cpn { @@_grab_m_4:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:nnnn { } { } { } { }
-  }
-\cs_new_protected:cpn { @@_grab_m_5:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:nnn { } { } { }
-  }
-\cs_new_protected:cpn { @@_grab_m_6:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:nn { } { }
-  }
-\cs_new_protected:cpn { @@_grab_m_7:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \use_none:n { }
-  }
-\cs_new_protected:cpn { @@_grab_m_8:w } #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \exp_after:wN \cs_set_eq:NN \l_@@_fn_tl \@@_grab_m_aux:Nnnnnnnnn
-    \l_@@_fn_tl \prg_do_nothing:
-  }
-\cs_new_protected:cpx { @@_grab_m_9:w }
-  {
-    \exp_not:c { @@_grab_m_5:w }
-    \exp_not:c { @@_grab_m_4:w }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_R:w, \@@_grab_R_long:w}
-% \begin{macro}{\@@_grab_R_aux:NNnN}
-%  The grabber for \texttt{R}-type arguments is basically the same as
-%  that for \texttt{D}-type ones, but always skips spaces (as it is mandatory)
-%  and has a hard-coded error message.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_R:w #1#2#3 \@@_run_code:
-  { \@@_grab_R_aux:NNnN #1 #2 {#3} \cs_set_protected_nopar:Npn }
-\cs_new_protected:Npn \@@_grab_R_long:w #1#2#3 \@@_run_code:
-  { \@@_grab_R_aux:NNnN #1 #2 {#3} \cs_set_protected:Npn }
-\cs_new_protected:Npn \@@_grab_R_aux:NNnN #1#2#3#4
-  {
-    \@@_grab_D_aux:NNnN #1 #2 {#3} #4
-    \@@_peek_nonspace_remove:NTF #1
-      { \@@_grab_D_call:Nw #1 }
-      {
-        \__kernel_msg_error:nnxx { xparse } { missing-required }
-          { \@@_environment_or_command: }
-          { \token_to_str:N #1 }
-        \@@_add_arg:o \c_novalue_tl
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_t:w}
-% \begin{macro}{\@@_grab_t_obey_spaces:w}
-% \begin{macro}{\@@_grab_t_aux:NNw}
-%   Dealing with a token is quite easy. Check the match, remove the
-%   token if needed and add a flag to the output.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_t:w
-  { \@@_grab_t_aux:NNw \@@_peek_nonspace_remove:NTF }
-\cs_new_protected:Npn \@@_grab_t_obey_spaces:w
-  { \@@_grab_t_aux:NNw \@@_peek_meaning_remove:NTF }
-\cs_new_protected:Npn \@@_grab_t_aux:NNw #1#2#3 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#3}
-    \exp_after:wN \cs_set_protected:Npn \l_@@_fn_tl
-      {
-        #1 #2
-          { \@@_add_arg:n { \BooleanTrue } }
-          { \@@_add_arg:n { \BooleanFalse } }
-      }
-    \l_@@_fn_tl
-  }
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
@@ -3522,8 +1306,6 @@
 %   Grabbing up to a list of tokens is quite easy: define the grabber,
 %   and then collect.
 %    \begin{macrocode}
-%</core>
-%<*package>
 \cs_new_protected:Npn \@@_grab_u:w #1#2 \@@_run_code:
   { \@@_grab_u_aux:nnN {#1} {#2} \cs_set_protected_nopar:Npn }
 \cs_new_protected:Npn \@@_grab_u_long:w #1#2 \@@_run_code:
@@ -3535,651 +1317,11 @@
       { \@@_add_arg:n {##1} }
     \l_@@_fn_tl
   }
-%</package>
-%<*core>
 %    \end{macrocode}
 % \end{macro}
 % \end{macro}
 % \end{macro}
 %
-% \begin{macro}{\@@_grab_v:w}
-% \begin{macro}{\@@_grab_v_long:w}
-% \begin{macro}{\@@_grab_v_aux:w}
-% \begin{macro}{\@@_grab_v_group_end:}
-% \begin{variable}{\l_@@_v_arg_tl}
-%   The opening delimiter is the first non-space token, and is never
-%   read verbatim.  This is required by consistency with the case where
-%   the preceding argument was optional and absent: then \TeX{} has
-%   already read and tokenized that token when looking for the optional
-%   argument.  The first thing is thus to check is that this delimiter
-%   is a character, and to distinguish the case of a left brace (in that
-%   case, \cs{group_align_safe_end:} is needed to compensate for the
-%   begin-group character that was just seen).  Then set verbatim
-%   catcodes with \cs{@@_grab_v_aux_catcodes:}.
-%
-%   The group keep catcode changes local, and
-%   \cs{group_align_safe_begin/end:} allow to use a character
-%   with category code~$4$ (normally |&|) as the delimiter.
-%   It is ended by \cs{@@_grab_v_group_end:}, which smuggles
-%   the collected argument out of the group.
-%    \begin{macrocode}
-\tl_new:N \l_@@_v_arg_tl
-\cs_new_protected:Npn \@@_grab_v:w
-  {
-    \bool_set_false:N \l_@@_long_bool
-    \@@_grab_v_aux:w
-  }
-\cs_new_protected:Npn \@@_grab_v_long:w
-  {
-    \bool_set_true:N \l_@@_long_bool
-    \@@_grab_v_aux:w
-  }
-\cs_new_protected:Npn \@@_grab_v_aux:w #1 \@@_run_code:
-  {
-    \tl_set:Nn \l_@@_signature_tl {#1}
-    \group_begin:
-      \group_align_safe_begin:
-        \tex_escapechar:D = 92 \scan_stop:
-        \tl_clear:N \l_@@_v_arg_tl
-        \peek_remove_spaces:n
-          {
-            \peek_meaning_remove:NTF \c_group_begin_token
-              {
-                \group_align_safe_end:
-                \@@_grab_v_bgroup:
-              }
-              {
-                \peek_N_type:TF
-                  { \@@_grab_v_aux_test:N }
-                  { \@@_grab_v_aux_abort:n { } }
-              }
-          }
-  }
-\cs_new_protected:Npn \@@_grab_v_group_end:
-  {
-        \group_align_safe_end:
-        \exp_args:NNNo
-      \group_end:
-    \tl_set:Nn \l_@@_v_arg_tl { \l_@@_v_arg_tl }
-  }
-%    \end{macrocode}
-% \end{variable}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_v_aux_test:N}
-% \begin{macro}
-%   {
-%     \@@_grab_v_aux_loop:N,
-%     \@@_grab_v_aux_loop:NN,
-%     \@@_grab_v_aux_loop_end:
-%   }
-%   Check that the opening delimiter is a character, setup category codes,
-%   then start reading tokens one by one, keeping the delimiter as an argument.
-%   If the verbatim was not nested, we will be grabbing one character
-%   at each step. Unfortunately, it can happen that what follows the
-%   verbatim argument is already tokenized. Thus, we check at each step
-%   that the next token is indeed a \enquote{nice}
-%   character, \emph{i.e.}, is not a character with
-%   category code $1$ (begin-group), $2$ (end-group)
-%   or $6$ (macro parameter), nor the space character,
-%   with category code~$10$ and character code~$32$,
-%   nor a control sequence.
-%   The partially built argument is stored in \cs{l_@@_v_arg_tl}.
-%   If we ever meet a token which we cannot grab (non-N-type),
-%   or which is not a character according to
-%   \cs{@@_grab_v_token_if_char:NTF}, then we bail out with
-%   \cs{@@_grab_v_aux_abort:n}. Otherwise, we stop at the first
-%   character matching the delimiter.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_v_aux_test:N #1
-  {
-    \@@_grab_v_token_if_char:NTF #1
-      {
-        \@@_grab_v_aux_put:N #1
-        \@@_grab_v_aux_catcodes:
-        \@@_grab_v_aux_loop:N #1
-      }
-      { \@@_grab_v_aux_abort:n {#1} #1 }
-  }
-\cs_new_protected:Npn \@@_grab_v_aux_loop:N #1
-  {
-    \peek_N_type:TF
-      { \@@_grab_v_aux_loop:NN #1 }
-      { \@@_grab_v_aux_abort:n { } }
-  }
-\cs_new_protected:Npn \@@_grab_v_aux_loop:NN #1#2
-  {
-    \@@_grab_v_token_if_char:NTF #2
-      {
-        \token_if_eq_charcode:NNTF #1 #2
-          { \@@_grab_v_aux_loop_end: }
-          {
-            \@@_grab_v_aux_put:N #2
-            \@@_grab_v_aux_loop:N #1
-          }
-      }
-      { \@@_grab_v_aux_abort:n {#2} #2 }
-  }
-\cs_new_protected:Npn \@@_grab_v_aux_loop_end:
-  {
-    \@@_grab_v_group_end:
-    \@@_add_arg:x { \tl_tail:N \l_@@_v_arg_tl }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_v_bgroup:}
-% \begin{macro}{\@@_grab_v_bgroup_loop:}
-% \begin{macro}{\@@_grab_v_bgroup_loop:N}
-% \begin{variable}{\l_@@_v_nesting_int}
-%   If the opening delimiter is a left brace, we keep track of
-%   how many left and right braces were encountered so far in
-%   \cs{l_@@_v_nesting_int} (the methods used for optional
-%   arguments cannot apply here), and stop as soon as it reaches~$0$.
-%
-%   Some care was needed when removing the opening delimiter, which
-%   has already been assigned category code~$1$: using
-%   \cs{peek_meaning_remove:NTF} in the \cs{@@_grab_v_aux:w}
-%   function would break within alignments. Instead, we first
-%   convert that token to a string, and remove the result as a
-%   normal undelimited argument.
-%    \begin{macrocode}
-\int_new:N \l_@@_v_nesting_int
-\cs_new_protected:Npx \@@_grab_v_bgroup:
-  {
-    \exp_not:N \@@_grab_v_aux_catcodes:
-    \exp_not:n { \int_set:Nn \l_@@_v_nesting_int { 1 } }
-    \exp_not:N \@@_grab_v_aux_put:N \iow_char:N \{
-    \exp_not:N \@@_grab_v_bgroup_loop:
-  }
-\cs_new_protected:Npn \@@_grab_v_bgroup_loop:
-  {
-    \peek_N_type:TF
-      { \@@_grab_v_bgroup_loop:N }
-      { \@@_grab_v_aux_abort:n { } }
-  }
-\cs_new_protected:Npn \@@_grab_v_bgroup_loop:N #1
-  {
-    \@@_grab_v_token_if_char:NTF #1
-      {
-        \token_if_eq_charcode:NNTF \c_group_end_token #1
-          {
-            \int_decr:N \l_@@_v_nesting_int
-            \int_compare:nNnTF \l_@@_v_nesting_int > 0
-              {
-                \@@_grab_v_aux_put:N #1
-                \@@_grab_v_bgroup_loop:
-              }
-              { \@@_grab_v_aux_loop_end: }
-          }
-          {
-            \token_if_eq_charcode:NNT \c_group_begin_token #1
-              { \int_incr:N \l_@@_v_nesting_int }
-            \@@_grab_v_aux_put:N #1
-            \@@_grab_v_bgroup_loop:
-          }
-      }
-      { \@@_grab_v_aux_abort:n {#1} #1 }
-  }
-%    \end{macrocode}
-% \end{variable}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_v_aux_catcodes:}
-% \begin{macro}{\@@_grab_v_aux_abort:n}
-%   The approach for short verbatim arguments is to make the end-line
-%   character a macro parameter character: this is forbidden by the
-%   rest of the code. Then the error branch can check what caused the
-%   bail out and give the appropriate error message.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_v_aux_catcodes:
-  {
-    \cs_set_eq:NN \do \char_set_catcode_other:N
-    \dospecials
-    \tex_endlinechar:D = `\^^M \scan_stop:
-    \bool_if:NTF \l_@@_long_bool
-      { \char_set_catcode_other:n { \tex_endlinechar:D } }
-      { \char_set_catcode_parameter:n { \tex_endlinechar:D } }
-  }
-\cs_new_protected:Npn \@@_grab_v_aux_abort:n #1
-  {
-    \@@_grab_v_group_end:
-    \exp_after:wN \exp_after:wN \exp_after:wN
-      \peek_meaning_remove:NTF \char_generate:nn { \tex_endlinechar:D } { 6 }
-      {
-        \__kernel_msg_error:nnxxx { xparse } { verbatim-newline }
-          { \@@_environment_or_command: }
-          { \tl_to_str:N \l_@@_v_arg_tl }
-          { \tl_to_str:n {#1} }
-        \@@_add_arg:o \c_novalue_tl
-      }
-      {
-        \__kernel_msg_error:nnxxx { xparse } { verbatim-tokenized }
-          { \@@_environment_or_command: }
-          { \tl_to_str:N \l_@@_v_arg_tl }
-          { \tl_to_str:n {#1} }
-        \@@_add_arg:o \c_novalue_tl
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_v_aux_put:N}
-%   Storing one token in the collected argument. Most tokens are
-%   converted to category code $12$, with the exception of active
-%   characters, and spaces (not sure what should be done for those).
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_v_aux_put:N #1
-  {
-    \tl_put_right:Nx \l_@@_v_arg_tl
-      {
-        \token_if_active:NTF #1
-          { \exp_not:N #1 } { \token_to_str:N #1 }
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_grab_v_token_if_char:NTF}
-%   This function assumes that the escape character is printable.
-%   Then the string representation of control sequences is at least
-%   two characters, and \cs{str_tail:n} only removes the escape
-%   character. Macro parameter characters are doubled by
-%   \cs{tl_to_str:n}, and will also yield a non-empty result,
-%   hence are not considered as characters.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_grab_v_token_if_char:NTF #1
-  { \str_if_eq:eeTF { } { \str_tail:n {#1} } }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_add_arg:n, \@@_add_arg:V, \@@_add_arg:o, \@@_add_arg:x}
-%   When an argument is found it is stored, then further arguments are
-%   grabbed by calling \cs{l_@@_signature_tl}.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_add_arg:n #1
-  {
-    \tl_put_right:Nn \l_@@_args_tl { {#1} }
-    \l_@@_signature_tl \@@_run_code:
-  }
-\cs_generate_variant:Nn \@@_add_arg:n { V , o , x }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsection{Grabbing arguments expandably}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_D:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_D:NNNwNNn}
-% \begin{macro}[EXP]{\@@_expandable_grab_D:NNNwNNnnn}
-% \begin{macro}[EXP]{\@@_expandable_grab_D:Nw}
-% \begin{macro}[EXP]{\@@_expandable_grab_D:nnNNNwNN}
-%   The first step is to grab the first token or group. The generic grabbers
-%   \cs{\meta{function}}\verb*| | and \cs{\meta{function}}\verb*| | are just after \cs{q_@@}, we go and find
-%   them (and use the long one).
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_D:w #1 \q_@@ #2#3
-  { #2 { \@@_expandable_grab_D:NNNwNNn #1 \q_@@ #2 #3 } }
-%    \end{macrocode}
-%   We then wish to test whether |#7|, which we just grabbed, is exactly |#2|.
-%   A preliminary test is whether their string representations coincide, then
-%   expand the only grabber function we have, |#1|, once: the two strings below
-%   are equal if and only if |#7| matches |#2| exactly.\footnote{It is obvious
-%   that if \texttt{\#7} matches \texttt{\#2} then the strings are equal. We
-%   must check the converse. The right-hand-side of \cs{str_if_eq:onTF} does
-%   not end with \texttt{\#3}, implying that the grabber function took
-%   everything as its arguments. The first brace group can only be empty if
-%   \texttt{\#7} starts with \texttt{\#2}, otherwise the brace group preceding
-%   \texttt{\#7} would not vanish. The third brace group is empty, thus the
-%   \cs{q_@@} that was used by our grabber \texttt{\#1} must be the one
-%   that we inserted (not some token in \texttt{\#7}), hence the second brace
-%   group contains the end of \texttt{\#7} followed by \texttt{\#2}. Since this
-%   is \texttt{\#2} on the right-hand-side, and no brace can be lost there,
-%   \texttt{\#7} must contain nothing else than its leading \texttt{\#2}.}
-%   The preliminary test is needed as |#7| could validly contain
-%   \tn{par} (because a later mandatory argument could be long) and our
-%   grabber may be short.  If
-%   |#7| does not match |#2|, then the optional argument is missing, we use the
-%   default |-NoValue-|, and put back the argument |#7| in the input stream.
-%
-%   If it does match, then interesting things need to be done. We will grab the
-%   argument piece by piece, with the following pattern:
-%   \begin{quote}
-%     \meta{grabber} \Arg{tokens} \\
-%     ~~\cs{q_nil} \Arg{piece 1} \meta{piece 2} \cs{ERROR} \cs{q_@@}\\
-%     ~~\cs{q_nil} \meta{input stream}
-%   \end{quote}
-%   The \meta{grabber} will find an opening delimiter in \meta{piece 2}, take
-%   the \cs{q_@@} as a second delimiter, and find more material delimited
-%   by the closing delimiter in the \meta{input stream}. We then move the part
-%   before the opening delimiter from \meta{piece 2} to \meta{piece 1}, and the
-%   material taken from the \meta{input stream} to the \meta{piece 2}. Thus,
-%   the argument moves gradually from the \meta{input stream} to the
-%   \meta{piece 2}, then to the \meta{piece 1} when we have made sure to find
-%   all opening and closing delimiters. This two-step process ensures that
-%   nesting works: the number of opening delimiters minus closing delimiters in
-%   \meta{piece 1} is always equal to the number of closing delimiters in
-%   \meta{piece 2}. We stop grabbing arguments once the \meta{piece 2} contains
-%   no opening delimiter any more, hence the balance is reached, and the final
-%   argument is \meta{piece 1} \meta{piece 2}.
-%   The indirection via \cs{@@_tmp:w} allows to insert |-NoValue-| expanded.
-%    \begin{macrocode}
-\cs_set_protected:Npn \@@_tmp:w #1
-  {
-    \cs_new:Npn \@@_expandable_grab_D:NNNwNNn ##1##2##3##4 \q_@@ ##5##6##7
-      {
-        \str_if_eq:nnTF {##2} {##7}
-          {
-            \str_if_eq:onTF
-              { ##1 { } { } ##7 ##2 \q_@@ ##3 }
-              { { } {##2} { } }
-          }
-          { \use_ii:nn }
-          {
-            ##1
-              { \@@_expandable_grab_D:NNNwNNnnn ##1##2##3##4 \q_@@ ##5##6 }
-              \q_nil { } ##2 \ERROR \q_@@ \ERROR
-          }
-          { ##4 {#1} \q_@@ ##5 ##6 {##7} }
-      }
-  }
-\exp_args:No \@@_tmp:w { \c_novalue_tl }
-%    \end{macrocode}
-%   At this stage, |#7| is \cs{q_nil} \Arg{piece 1} \meta{more for piece 1},
-%   and we want to concatenate all that, removing \cs{q_nil}, and keeping the
-%   opening delimiter |#2|. Simply use \cs{use_ii:nn}. Also, |#8| is
-%   \meta{remainder of piece 2} \cs{ERROR}, and |#9| is \cs{ERROR} \meta{more
-%   for piece 2}. We concatenate those, replacing the two \cs{ERROR} by the
-%   closing delimiter |#3|.
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_D:NNNwNNnnn #1#2#3#4 \q_@@ #5#6#7#8#9
-  {
-    \exp_args:Nof \@@_expandable_grab_D:nnNNNwNN
-      { \use_ii:nn #7 #2 }
-      { \@@_expandable_grab_D:Nw #3 \exp_stop_f: #8 #9 }
-    #1#2#3 #4 \q_@@ #5 #6
-  }
-\cs_new:Npn \@@_expandable_grab_D:Nw #1#2 \ERROR \ERROR { #2 #1 }
-%    \end{macrocode}
-%   Armed with our two new \meta{pieces}, we are ready to loop. However, we
-%   must first see if \meta{piece 2} (here |#2|) contains any opening
-%   delimiter |#4|. Again, we expand |#3|, this time removing its whole output
-%   with \cs{use_none:nnn}. The test is similar to \cs{tl_if_in:nnTF}. The
-%   token list is empty if and only if |#2| does not contain the opening
-%   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:NNNwNNnnn}. 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:nnNNNwNN #1#2#3#4#5#6 \q_@@ #7#8
-  {
-    \exp_args:No \tl_if_empty:oTF
-      { #3 { \use_none:nnn } #2 \q_@@ #5 #4 \q_@@ #5 }
-      {
-        \tl_if_blank:oTF { \use_none:nn #1#2 }
-          { \@@_put_arg_expandable:ow { \use_none:nn #1#2 } }
-          {
-            \str_if_eq:eeTF
-              { \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 #8
-      }
-      {
-        #3
-          { \@@_expandable_grab_D:NNNwNNnnn #3#4#5#6 \q_@@ #7 #8 }
-          \q_nil {#1} #2 \ERROR \q_@@ \ERROR
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_D_alt:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_D_alt:NNwNNn}
-% \begin{macro}[EXP]{\@@_expandable_grab_D_alt:Nwn}
-%   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 but there cannot be any nesting.
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_D_alt:w #1 \q_@@ #2#3
-  { #2 { \@@_expandable_grab_D_alt:NNwNNn #1 \q_@@ #2 #3 } }
-\cs_set_protected:Npn \@@_tmp:w #1
-  {
-    \cs_new:Npn \@@_expandable_grab_D_alt:NNwNNn ##1##2##3 \q_@@ ##4##5##6
-      {
-        \str_if_eq:nnTF {##6} {##2}
-          {
-            \str_if_eq:onTF
-              { ##1 { } ##6 ##2 ##2 }
-              { { } ##2 }
-          }
-          { \use_ii:nn }
-          {
-            ##1
-              { \@@_expandable_grab_D_alt:NNwn ##4 ##5 ##3 \q_@@ }
-              ##6 \ERROR
-          }
-          { ##3 {#1} \q_@@ ##4 ##5 {##6} }
-      }
-  }
-\exp_args:No \@@_tmp:w { \c_novalue_tl }
-\cs_new:Npn \@@_expandable_grab_D_alt:NNwn #1#2#3 \q_@@ #4
-  {
-    \tl_if_blank:oTF { \use_none:n #4 }
-      { \@@_put_arg_expandable:ow { \use_none:n #4 } }
-      {
-        \str_if_eq:eeTF
-          { \exp_not:o { \use_none:n #4 } }
-          { { \exp_not:o { \use_ii:nnn #4 \q_nil } } }
-          { \@@_put_arg_expandable:ow { \use_ii:nn #4 } }
-          { \@@_put_arg_expandable:ow { \use_none:n #4 } }
-      }
-        #3 \q_@@ #1 #2
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_E:w, \@@_expandable_grab_E_long:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_E_aux:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_E_test:nnw}
-% \begin{macro}[EXP]{\@@_expandable_grab_E_loop:nnnNNw}
-% \begin{macro}[EXP]{\@@_expandable_grab_E_find:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_E_find:nnw}
-% \begin{macro}[EXP]{\@@_expandable_grab_E_end:nnw}
-%   We keep track of long/short by placing the appropriate grabber as
-%   the third token after \cs{q_@@}; it is eventually removed by the
-%   \texttt{end:nnw} auxiliary.  The \texttt{aux:w} auxiliary will be
-%   called repeatedly with two arguments: the set
-%   of pairs \meta{parser} \meta{token}, and the set of arguments found
-%   so far (initially all |{-NoValue-}|).  At each step, grab what
-%   follows in the input stream then call the \texttt{loop:nnnNNw}
-%   auxiliary to compare it with each possible embellishment in turn.
-%   This auxiliary's |#1| is what was found in the input, |#2| collects
-%   \meta{parser} \meta{token} pairs that did not match, |#3| collects
-%   the corresponding arguments found previously, |#4| and |#5| is the
-%   current pair, |#6| is the remaining pairs, |#7| is empty or two
-%   \cs{q_nil}, and |#8| is the current argument.  If none of the pairs
-%   matched (determined by \cs{quark_if_nil:NTF}) then call the
-%   \texttt{end} auxiliary to stop looking for embellishments,
-%   remembering to put what was grabbed in the input back where it
-%   belongs, and storing the arguments found just before \cs{q_@@}.  If
-%   the current argument |#8| is not |-NoValue-| or if the input |#1|
-%   does not match |#5| (see \texttt{t}-type arguments below for a
-%   similar \cs{str_if_eq:onTF} test) then carry on the loop.
-%   Otherwise, we found a new embellishment: grab the corresponding
-%   argument in the input using the \texttt{find:w} auxiliary.  To avoid
-%   losing braces around that auxiliary's argument we include a
-%   space, which will be eliminated in the next loop through
-%   embellishments.
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_E:w #1 \q_@@ #2#3
-  { \@@_expandable_grab_E_aux:w #1 \q_@@ #2 #3 #3 }
-\cs_new:Npn \@@_expandable_grab_E_long:w #1 \q_@@ #2#3
-  { \@@_expandable_grab_E_aux:w #1 \q_@@ #2 #3 #2 }
-\cs_new:Npn \@@_expandable_grab_E_aux:w #1 \q_@@ #2#3#4
-  { #2 { \@@_expandable_grab_E_test:nnw #1 \q_@@ #2 #3 #4 } }
-\cs_new:Npn \@@_expandable_grab_E_test:nnw #1#2#3 \q_@@ #4#5#6#7
-  {
-    \@@_expandable_grab_E_loop:nnnNNw {#7} { } { }
-      #1 \q_nil \q_nil \q_nil \q_mark #2 \q_nil
-    #3 \q_@@ #4 #5 #6
-  }
-\cs_new:Npn \@@_expandable_grab_E_loop:nnnNNw
-    #1#2#3#4#5#6 \q_nil #7 \q_mark #8
-  {
-    \quark_if_nil:NTF #4
-      { \@@_expandable_grab_E_end:nnw {#1} {#3} }
-      {
-        \tl_if_novalue:nTF {#8}
-          { \str_if_eq:onTF { #4 { } #1 #5 } {#5} }
-          { \use_ii:nn }
-            { \@@_expandable_grab_E_find:w { #2 #4 #5 #6 } {#3} ~ }
-            {
-              \@@_expandable_grab_E_loop:nnnNNw
-                {#1} { #2 #4 #5 } { #3 {#8} }
-                #6 \q_nil #7 \q_mark
-            }
-      }
-  }
-\cs_new:Npn \@@_expandable_grab_E_find:w #1 \q_@@ #2#3#4
-  { #4 { \@@_expandable_grab_E_find:nnw #1 \q_@@ #2 #3 #4 } }
-\cs_new:Npn \@@_expandable_grab_E_find:nnw #1#2#3 \q_nil #4 \q_@@ #5#6#7#8
-  { \@@_expandable_grab_E_aux:w {#1} { #2 {#8} #3 } #4 \q_@@ #5 #6 #7 }
-\cs_new:Npn \@@_expandable_grab_E_end:nnw #1#2#3 \q_@@ #4#5#6
-  { #3 #2 \q_@@ #4 #5 {#1} }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_m:w, \@@_expandable_grab_m_long:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_m_aux:wNn}
-%   The mandatory case is easy: find the auxiliary after the \cs{q_@@},
-%   and use it directly to grab the argument, then correctly position
-%   the argument before \cs{q_@@}.
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_m:w #1 \q_@@ #2#3
-  { #3 { \@@_expandable_grab_m_aux:wNn #1 \q_@@ #2 #3 } }
-\cs_new:Npn \@@_expandable_grab_m_long:w #1 \q_@@ #2#3
-  { #2 { \@@_expandable_grab_m_aux:wNn #1 \q_@@ #2 #3 } }
-\cs_new:Npn \@@_expandable_grab_m_aux:wNn #1 \q_@@ #2#3#4
-  { #1 {#4} \q_@@ #2 #3 }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_R:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_R_aux:NNNwNNn}
-%   Much the same as for the \texttt{D}-type argument, with only the lead-off
-%   function varying.
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_R:w #1 \q_@@ #2#3
-  { #2 { \@@_expandable_grab_R_aux:NNNwNNn #1 \q_@@ #2#3 } }
-\cs_set_protected:Npn \@@_tmp:w #1
-  {
-    \cs_new:Npn \@@_expandable_grab_R_aux:NNNwNNn ##1##2##3##4 \q_@@ ##5##6##7
-      {
-        \str_if_eq:nnTF {##7} {##2}
-          {
-            \str_if_eq:onTF
-              { ##1 { } { } ##7 ##2 \q_@@ ##3 }
-              { { } {##2} { } }
-          }
-          { \use_ii:nn }
-          {
-            ##1
-              { \@@_expandable_grab_D:NNNwNNnnn ##1##2##3##4 \q_@@ ##5##6 }
-              \q_nil { } ##2 \ERROR \q_@@ \ERROR
-          }
-          {
-            \__kernel_msg_expandable_error:nnff
-              { xparse } { missing-required }
-              { \exp_args:Nf \tl_trim_spaces:n { \token_to_str:N ##5 } }
-              { \tl_to_str:n {##2} }
-            ##4 {#1} \q_@@ ##5 ##6 {##7}
-          }
-      }
-  }
-\exp_args:No \@@_tmp:w { \c_novalue_tl }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_R_alt:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_R_alt_aux:NNwNNn}
-%   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}
-\cs_new:Npn \@@_expandable_grab_R_alt:w #1 \q_@@ #2#3
-  { #2 { \@@_expandable_grab_R_alt_aux:NNwNNn #1 \q_@@ #2#3 } }
-\cs_set_protected:Npn \@@_tmp:w #1
-  {
-    \cs_new:Npn \@@_expandable_grab_R_alt_aux:NNwNNn ##1##2##3 \q_@@ ##4##5##6
-      {
-        \str_if_eq:nnTF {##6} {##2}
-          {
-            \str_if_eq:onTF
-              { ##1 { } ##6 ##2 ##2 }
-              { { } ##2 }
-          }
-          { \use_ii:nn }
-          {
-            ##1
-              { \@@_expandable_grab_D_alt:NNwn ##4 ##5 ##3 \q_@@ }
-              ##6 \ERROR
-          }
-          {
-            \__kernel_msg_expandable_error:nnff
-              { xparse } { missing-required }
-              { \exp_args:Nf \tl_trim_spaces:n { \token_to_str:N ##4 } }
-              { \tl_to_str:n {##2} }
-            ##3 {#1} \q_@@ ##4 ##5 {##6}
-          }
-      }
-  }
-\exp_args:No \@@_tmp:w { \c_novalue_tl }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}[EXP]{\@@_expandable_grab_t:w}
-% \begin{macro}[EXP]{\@@_expandable_grab_t_aux:NNwn}
-%   As for a \texttt{D}-type argument, here we compare the grabbed tokens using
-%   the only parser we have in order to work out if |#2| is exactly equal to
-%   the output of the grabber.
-%    \begin{macrocode}
-\cs_new:Npn \@@_expandable_grab_t:w #1 \q_@@ #2#3
-  { #2 { \@@_expandable_grab_t_aux:NNwn #1 \q_@@ #2 #3 } }
-\cs_new:Npn \@@_expandable_grab_t_aux:NNwn #1#2#3 \q_@@ #4#5#6
-  {
-    \str_if_eq:onTF { #1 { } #6 #2 } {#2}
-      { #3 { \BooleanTrue } \q_@@ #4 #5 }
-      { #3 { \BooleanFalse } \q_@@ #4 #5 {#6} }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
 % \begin{macro}[EXP]{\@@_expandable_grab_u:w}
 %   It turns out there is nothing to do: this is followed by an
 %   auxiliary named after the function, that does everything.
@@ -4188,991 +1330,8 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}[EXP]
-%   {\@@_put_arg_expandable:nw, \@@_put_arg_expandable:ow}
-%   A useful helper, to store arguments when they are ready.
-%    \begin{macrocode}
-\cs_new:Npn \@@_put_arg_expandable:nw #1#2 \q_@@ { #2 {#1} \q_@@ }
-\cs_generate_variant:Nn \@@_put_arg_expandable:nw { o }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsection{Argument processors}
-%
-% \begin{macro}{\@@_bool_reverse:N}
-%   A simple reversal.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_bool_reverse:N #1
-  {
-    \bool_if:NTF #1
-      { \tl_set:Nn \ProcessedArgument { \c_false_bool } }
-      { \tl_set:Nn \ProcessedArgument { \c_true_bool } }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{variable}{\l_@@_split_list_seq, \l_@@_split_list_tl}
-% \begin{macro}{\@@_split_list:nn}
-% \begin{macro}{\@@_split_list_multi:nn, \@@_split_list_multi:nV}
-% \begin{macro}{\@@_split_list_single:Nn}
-%   Splitting can take place either at a single token or at a longer
-%   identifier. To deal with single active tokens, a two-part procedure is
-%   needed.
-%    \begin{macrocode}
-\seq_new:N \l_@@_split_list_seq
-\tl_new:N \l_@@_split_list_tl
-\cs_new_protected:Npn \@@_split_list:nn #1#2
-  {
-    \tl_if_single:nTF {#1}
-      {
-        \token_if_cs:NTF #1
-          { \@@_split_list_multi:nn {#1} {#2} }
-          { \@@_split_list_single:Nn #1 {#2} }
-      }
-      { \@@_split_list_multi:nn {#1} {#2} }
-  }
-\cs_new_protected:Npn \@@_split_list_multi:nn #1#2
-  {
-    \seq_set_split:Nnn \l_@@_split_list_seq {#1} {#2}
-    \tl_clear:N \ProcessedArgument
-    \seq_map_inline:Nn \l_@@_split_list_seq
-      { \tl_put_right:Nn \ProcessedArgument { {##1} } }
-  }
-\cs_generate_variant:Nn \@@_split_list_multi:nn { nV }
-\group_begin:
-\char_set_catcode_active:N \^^@
-\cs_new_protected:Npn \@@_split_list_single:Nn #1#2
-  {
-    \tl_set:Nn \l_@@_split_list_tl {#2}
-    \group_begin:
-    \char_set_lccode:nn { `\^^@ } { `#1 }
-    \tex_lowercase:D
-      {
-        \group_end:
-        \tl_replace_all:Nnn \l_@@_split_list_tl { ^^@ }
-      }   {#1}
-     \@@_split_list_multi:nV {#1} \l_@@_split_list_tl
-   }
-\group_end:
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{variable}
-%
-% \begin{macro}{\@@_split_argument:nnn}
-% \begin{macro}{\@@_split_argument_aux:nnnn}
-% \begin{macro}[EXP]{\@@_split_argument_aux:n}
-% \begin{macro}[rEXP]{\@@_split_argument_aux:wn}
-%   Splitting to a known number of items is a special version of splitting
-%   a list, in which the limit is hard-coded and where there will always be
-%   exactly the correct number of output items. An auxiliary function is
-%   used to save on working out the token list length several times.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_split_argument:nnn #1#2#3
-  {
-    \@@_split_list:nn {#2} {#3}
-    \exp_args:Nf \@@_split_argument_aux:nnnn
-      { \tl_count:N \ProcessedArgument }
-      {#1} {#2} {#3}
-  }
-\cs_new_protected:Npn \@@_split_argument_aux:nnnn #1#2#3#4
-  {
-    \int_compare:nNnF {#1} = { #2 + 1 }
-      {
-        \int_compare:nNnTF {#1} > { #2 + 1 }
-          {
-            \tl_set:Nx \ProcessedArgument
-              {
-                \exp_last_unbraced:NnNo
-                  \@@_split_argument_aux:n
-                  { #2 + 1 }
-                  \use_none_delimit_by_q_stop:w
-                  \ProcessedArgument
-                  \q_stop
-              }
-            \__kernel_msg_error:nnxxx { xparse } { split-excess-tokens }
-              { \tl_to_str:n {#3} } { \int_eval:n { #2 + 1 } }
-              { \tl_to_str:n {#4} }
-          }
-          {
-            \tl_put_right:Nx \ProcessedArgument
-              {
-                \prg_replicate:nn { #2 + 1 - (#1) }
-                  { { \exp_not:V \c_novalue_tl } }
-              }
-          }
-      }
-  }
-%    \end{macrocode}
-%   Auxiliaries to leave exactly the correct number of arguments in
-%   \cs{ProcessedArgument}.
-%    \begin{macrocode}
-\cs_new:Npn \@@_split_argument_aux:n #1
-  { \prg_replicate:nn {#1} { \@@_split_argument_aux:wn } }
-\cs_new:Npn \@@_split_argument_aux:wn #1 \use_none_delimit_by_q_stop:w #2
-  {
-    \exp_not:n { {#2} }
-    #1
-    \use_none_delimit_by_q_stop:w
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_trim_spaces:n}
-%   This one is almost trivial.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_trim_spaces:n #1
-  { \tl_set:Nx \ProcessedArgument { \tl_trim_spaces:n {#1} } }
-%    \end{macrocode}
-% \end{macro}
-%
-% \subsection{Access to the argument specification}
-%
-% \begin{macro}{\@@_get_arg_spec_error:N, \@@_get_arg_spec_error:n}
-% \begin{macro}{\@@_get_arg_spec_error_aux:n}
-%   Provide an informative error when trying to get the argument
-%   specification of a non-\pkg{xparse} command or environment.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_get_arg_spec_error:N #1
-  {
-    \bool_set_false:N \l_@@_environment_bool
-    \tl_set:Nn \l_@@_fn_tl {#1}
-    \@@_get_arg_spec_error_aux:n { \cs_if_exist:NTF #1 }
-  }
-\cs_new_protected:Npn \@@_get_arg_spec_error:n #1
-  {
-    \bool_set_true:N \l_@@_environment_bool
-    \str_set:Nx \l_@@_environment_str {#1}
-    \@@_get_arg_spec_error_aux:n
-      { \cs_if_exist:cTF { \l_@@_environment_str } }
-  }
-\cs_new_protected:Npn \@@_get_arg_spec_error_aux:n #1
-  {
-    #1
-      {
-        \__kernel_msg_error:nnx { xparse } { non-xparse }
-          { \@@_environment_or_command: }
-      }
-      {
-        \__kernel_msg_error:nnx { xparse } { unknown }
-          { \@@_environment_or_command: }
-      }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_get_arg_spec:NTF}
-%   If the command is not an \pkg{xparse} command, complain.  If it is,
-%   its second \enquote{item} is the argument specification.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_get_arg_spec:NTF #1#2#3
-  {
-    \@@_cmd_if_xparse:NTF #1
-      {
-        \tl_set:Nx \ArgumentSpecification { \tl_item:Nn #1 { 2 } }
-        #2
-      }
-      {#3}
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_get_arg_spec:N}
-% \begin{macro}{\@@_get_arg_spec:n}
-% \begin{variable}{\ArgumentSpecification}
-%   Recovering the argument specification is now trivial.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_get_arg_spec:N #1
-  {
-    \@@_get_arg_spec:NTF #1 { }
-      { \@@_get_arg_spec_error:N #1 }
-  }
-\cs_new_protected:Npn \@@_get_arg_spec:n #1
-  {
-    \exp_args:Nc \@@_get_arg_spec:NTF
-      { environment~ \tl_to_str:n {#1} }
-      { }
-      { \@@_get_arg_spec_error:n {#1} }
-  }
-\tl_new:N \ArgumentSpecification
-%    \end{macrocode}
-% \end{variable}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_show_arg_spec:N}
-% \begin{macro}{\@@_show_arg_spec:n}
-%   Showing the argument specification simply means finding it and then
-%   calling the \cs{tl_show:N} function.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_show_arg_spec:N #1
-  {
-    \@@_get_arg_spec:NTF #1
-      { \tl_show:N \ArgumentSpecification }
-      { \@@_get_arg_spec_error:N #1 }
-  }
-\cs_new_protected:Npn \@@_show_arg_spec:n #1
-  {
-    \exp_args:Nc \@@_get_arg_spec:NTF
-      { environment~ \tl_to_str:n {#1} }
-      { \tl_show:N \ArgumentSpecification }
-      { \@@_get_arg_spec_error:n {#1} }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Utilities}
-%
-% \begin{macro}{\@@_check_definable:nNT, \@@_check_definable_aux:nN}
-%   Check that a token list is appropriate as a first argument of
-%   \cs{NewDocumentCommand} and similar functions and otherwise
-%   produce an error.  First trim whitespace to allow for spaces around
-%   the actual command to be defined.  If the result has multiple
-%   tokens, it is not a valid argument.  The single token is a control
-%   sequence exactly if its string representation has more than one
-%   character (using \cs{token_to_str:N} rather than \cs{tl_to_str:n}
-%   to avoid problems with macro parameter characters, and setting
-%   \cs{tex_escapechar:D} to prevent it from being non-printable).
-%   Finally, check for an active character: this is done by lowercasing
-%   the token to fix its character code (arbitrarily to that of~|?|)
-%   and comparing the result to an active~|?|.  Both control sequences
-%   and active characters are valid arguments, and non-active character
-%   tokens are not.  In all cases, the group opened to keep assignments
-%   local must be closed.
 %    \begin{macrocode}
-\cs_new_protected:Npn \@@_check_definable:nNT #1
-  { \tl_trim_spaces_apply:nN {#1} \@@_check_definable_aux:nN }
-\group_begin:
-  \char_set_catcode_active:n { `? }
-  \cs_new_protected:Npn \@@_check_definable_aux:nN #1#2
-    {
-      \group_begin:
-      \tl_if_single_token:nTF {#1}
-        {
-          \int_set:Nn \tex_escapechar:D { 92 }
-          \exp_args:Nx \tl_if_empty:nTF
-            { \exp_args:No \str_tail:n { \token_to_str:N #1 } }
-            {
-              \exp_args:Nx \char_set_lccode:nn
-                { ` \str_head:n {#1} } { `? }
-              \tex_lowercase:D { \tl_if_eq:nnTF {#1} } { ? }
-                { \group_end: \use_iii:nnn }
-                { \group_end: \use_i:nnn }
-            }
-            { \group_end: \use_iii:nnn }
-        }
-        { \group_end: \use_ii:nnn }
-      {
-        \__kernel_msg_error:nnxx { xparse } { not-definable }
-          { \tl_to_str:n {#1} } { \token_to_str:N #2 }
-      }
-      {
-        \__kernel_msg_error:nnxx { xparse } { not-one-token }
-          { \tl_to_str:n {#1} } { \token_to_str:N #2 }
-      }
-    }
-\group_end:
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_token_if_cs:NTF}
-%   Based on the definition of \cs{@@_check_definable_aux:nN} above, but
-%   only checks for an actual control sequence (\emph{i.e.},
-%   \cs[no-index]{\meta{anything}}). \cs{tex_escapechar:D} is
-%   temporarily changed to a known value and then it checks if
-%   |\string#1| contains more than one character: if it does, it's a
-%   control sequence.  This test differs from \cs{token_if_cs:NTF} for
-%   example in \verb|\token_if_cs:NTF \c_group_begin_token {T}{F}|,
-%   where \cs{token_if_cs:NTF} returns false.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_token_if_cs:NTF #1
-  {
-    \group_begin:
-      \int_set:Nn \tex_escapechar:D { 92 }
-      \exp_args:Nx \tl_if_empty:nTF
-          { \exp_args:No \str_tail:n { \token_to_str:N #1 } }
-        { \group_end: \use_ii:nn }
-        { \group_end: \use_i:nn }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_tl_mapthread_function:NNN, \@@_tl_mapthread_function:nnN}
-% \begin{macro}{\@@_tl_mapthread_loop:w}
-%   Analogue of \cs{seq_mapthread_function:NNN} for token lists.
-%    \begin{macrocode}
-\cs_new:Npn \@@_tl_mapthread_function:NNN #1#2#3
-  {
-    \exp_after:wN \exp_after:wN
-    \exp_after:wN \@@_tl_mapthread_loop:w
-    \exp_after:wN \exp_after:wN
-    \exp_after:wN #3
-    \exp_after:wN #1
-    \exp_after:wN \q_recursion_tail
-    \exp_after:wN \q_mark
-    #2
-    \q_recursion_tail
-    \q_recursion_stop
-  }
-\cs_new:Npn \@@_tl_mapthread_function:nnN #1#2#3
-  {
-    \@@_tl_mapthread_loop:w #3
-      #1 \q_recursion_tail \q_mark
-      #2 \q_recursion_tail \q_recursion_stop
-  }
-\cs_new:Npn \@@_tl_mapthread_loop:w #1#2#3 \q_mark #4
-  {
-    \quark_if_recursion_tail_stop:n {#2}
-    \quark_if_recursion_tail_stop:n {#4}
-    #1 {#2} {#4}
-    \@@_tl_mapthread_loop:w #1#3 \q_mark
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_cmd_if_xparse:NTF}
-% \begin{macro}{\@@_cmd_if_xparse_aux:N}
-%   To determine whether the command is an \pkg{xparse} command check
-%   that its |arg_spec| is empty (this also excludes non-macros) and
-%   that its |replacement_spec| starts with either \cs{@@_start:nNNnnn}
-%   (non-expandable command) or \cs{@@_start_expandable:nNNNNn}
-%   (expandable command) or \cs{@@_start_env:nnnnn} (environment).
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_cmd_if_xparse:NTF #1
-  {
-    \exp_args:Nf \str_case_e:nnTF
-      {
-        \exp_args:Nf \tl_if_empty:nT { \cs_argument_spec:N #1 }
-          {
-            \exp_last_unbraced:Nf \@@_cmd_if_xparse_aux:w
-              { \cs_replacement_spec:N #1 } ~ \q_stop
-          }
-      }
-      {
-        { \token_to_str:N \@@_start:nNNnnn } { }
-        { \token_to_str:N \@@_start_expandable:nNNNNn } { }
-        { \token_to_str:N \@@_start_env:nnnnn } { }
-      }
-  }
-\cs_new:Npn \@@_cmd_if_xparse_aux:w #1 ~ #2 \q_stop {#1}
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\@@_peek_nonspace:NTF, \@@_peek_nonspace_remove:NTF, \@@_peek_nonspace_aux:nNNTF}
-%   Collect spaces in a loop, and put the collected spaces back in the
-%   false branch of a call to \cs{peek_meaning:NTF} or
-%   \cs{peek_meaning_remove:NTF}.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_peek_nonspace:NTF
-  { \@@_peek_nonspace_aux:nNNTF { } \@@_peek_meaning:NTF }
-\cs_new_protected:Npn \@@_peek_nonspace_remove:NTF
-  { \@@_peek_nonspace_aux:nNNTF { } \@@_peek_meaning_remove:NTF }
-\cs_new_protected:Npn \@@_peek_nonspace_aux:nNNTF #1#2#3#4#5
-  {
-    \peek_meaning_remove:NTF \c_space_token
-      { \@@_peek_nonspace_aux:nNNTF { #1 ~ } #2 #3 {#4} {#5} }
-      { #2 #3 { #4 } { #5 #1 } }
-  }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\@@_peek_meaning:NTF, \@@_peek_meaning_remove:NTF}
-% \begin{macro}{\@@_peek_cs_check_equal:NNN, \@@_peek_meaning_aux:NNTF, \@@_peek_true_remove:NNw}
-%   Peek ahead for a token with a given meaning.  In case the search
-%   token is a control sequence, also check that the \meta{csname} is
-%   the same as the control sequence peeked at.  This extra verification
-%   is necessary when the command is delimited by control sequence tokens
-%   (as opposed to character tokens), and we want the the exact same
-%   control sequence to match.
-%    \begin{macrocode}
-\cs_new_protected:Npn \@@_peek_meaning:NTF
-  { \@@_peek_meaning_aux:NNTF \c_false_bool }
-\cs_new_protected:Npn \@@_peek_meaning_remove:NTF
-  { \@@_peek_meaning_aux:NNTF \c_true_bool }
-\cs_new_protected:Npn \@@_peek_meaning_aux:NNTF #1#2#3#4
-  {
-    \tl_set:Nn \l_@@_tmpa_tl {#3}
-    \tl_set:Nn \l_@@_tmpb_tl {#4}
-    \peek_meaning:NTF #2
-      {
-        \token_if_eq_meaning:NNTF #2 \c_group_begin_token
-          { \@@_peek_true_remove:Nw #1 }
-          {
-            \@@_token_if_cs:NTF #2
-              { \@@_peek_cs_check_equal:NNN #1 #2 }
-              { \@@_peek_true_remove:Nw #1 }
-          }
-      }
-      { \l_@@_tmpb_tl }
-  }
-\cs_new_protected:Npn \@@_peek_cs_check_equal:NNN #1#2#3
-  {
-    \str_if_eq:nnTF {#2} {#3}
-      { \@@_peek_true_remove:Nw #1 }
-      { \l_@@_tmpb_tl }
-    #3
-  }
-\cs_new_protected:Npn \@@_peek_true_remove:Nw #1
-  {
-    \bool_if:NTF #1
-      {
-        \tex_afterassignment:D \l_@@_tmpa_tl
-        \cs_set_eq:NN \@@_tmp:w
-      }
-      { \l_@@_tmpa_tl }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \subsection{Messages}
-%
-% \begin{macro}{\@@_environment_or_command:}
-% \begin{variable}{\c_@@_ignore_def_tl}
-%   Two texts used in several messages.
-%    \begin{macrocode}
-\cs_new:Npn \@@_environment_or_command:
-  {
-    \bool_if:NTF \l_@@_environment_bool
-      { environment ~ ' \l_@@_environment_str ' }
-      {
-        command ~ '
-        \exp_args:Nf \tl_trim_spaces:n
-          { \exp_after:wN \token_to_str:N \l_@@_fn_tl }
-        '
-      }
-  }
-\tl_const:Nn \c_@@_ignore_def_tl
-  { \\ \\ LaTeX~will~ignore~this~entire~definition. }
-%    \end{macrocode}
-% \end{variable}
-% \end{macro}
-%
-% Some messages intended as errors when defining commands/environments.
-%    \begin{macrocode}
-\__kernel_msg_new:nnnn { xparse } { arg-after-body }
-  { In~the~definition~of~#1,~b~(body)~argument~must~be~last. }
-  {
-    The~'body'~argument~type~is~followed~by~'#2'~in~the~argument~
-    specification~of~the~#1.~This~is~not~allowed.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { bad-arg-spec }
-  { Bad~argument~specification~'#2'~for~#1. }
-  {
-    The~argument~specification~provided~was~not~valid:~
-    one~or~more~mandatory~pieces~of~information~were~missing.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { command-already-defined }
-  { Command~'#1'~already~defined! }
-  {
-    You~have~used~#2~
-    with~a~command~that~already~has~a~definition. \\ \\
-    The~existing~definition~of~'#1'~will~not~be~altered.
-  }
-\__kernel_msg_new:nnnn { xparse } { command-not-yet-defined }
-  { Command ~'#1'~not~yet~defined! }
-  {
-    You~have~used~#2~
-    with~a~command~that~was~never~defined.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { environment-already-defined }
-  { Environment~'#1'~already~defined! }
-  {
-    You~have~used~\NewDocumentEnvironment
-    with~an~environment~that~already~has~a~definition. \\ \\
-    The~existing~definition~of~'#1'~will~not~be~altered.
-  }
-\__kernel_msg_new:nnnn { xparse } { environment-not-yet-defined }
-  { Environment~'#1'~not~yet~defined! }
-  {
-    You~have~used~\RenewDocumentEnvironment
-    with~an~environment~that~was~never~defined.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { expandable-ending-optional }
-  {
-    Argument~specification~'#2'~for~expandable~command~'#1'~
-    ends~with~optional~argument.
-  }
-  {
-    Expandable~commands~must~have~a~final~mandatory~argument~
-    (or~no~arguments~at~all).~You~cannot~have~a~terminal~optional~
-    argument~with~expandable~commands.
-  }
-\__kernel_msg_new:nnnn { xparse } { inconsistent-long }
-  { Inconsistent~long~arguments~for~expandable~command~'#1'. }
-  {
-    The~arguments~for~an~expandable~command~must~not~involve~short~
-    arguments~after~long~arguments.~You~have~tried~to~mix~the~two~types.
-  }
-\__kernel_msg_new:nnnn { xparse } { invalid-command-arg }
-  { Argument~type~'#2'~not~available~for~#1. }
-  {
-    The~letter~'#2'~can~only~be~used~in~environment~argument~
-    specifications,~not~for~commands.
-    \\ \\
-    LaTeX~will~ignore~this~entire~definition.
-  }
-\__kernel_msg_new:nnnn { xparse } { invalid-expandable-argument-type }
-  { Argument~type~'#2'~not~available~for~expandable~command~'#1'. }
-  {
-    The~letter~'#2'~specifies~an~argument~type~which~cannot~be~used~
-    in~an~expandable~command.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { invalid-after-optional-expandably }
-  {
-    Argument~type~'#2'~not~available~after~optional~argument~
-    for~expandable~command~'#1'.
-  }
-  {
-    The~letter~'#2'~specifies~an~argument~type~which~cannot~be~used~
-    in~an~expandable~command~after~an~optional~argument.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { non-trailing-obey-spaces }
-  { Prefix~'!'~used~before~mandatory~argument~'#2'~of~#1. }
-  {
-    The~prefix~'!'~can~only~apply~to~trailing~optional~arguments.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { not-definable }
-  { First~argument~of~'#2'~must~be~a~command. }
-  {
-    The~first~argument~of~'#2'~should~be~the~document~command~that~will~
-    be~defined.~The~provided~argument~'#1'~is~a~character.~Perhaps~a~
-    backslash~is~missing?
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { not-one-token }
-  { First~argument~of~'#2'~must~be~a~command. }
-  {
-    The~first~argument~of~'#2'~should~be~the~document~command~that~will~
-    be~defined.~The~provided~argument~'#1'~contains~more~than~one~
-    token.~Perhaps~a~backslash~is~missing?
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { not-single-token }
-  {
-    Argument~delimiter~'#2'~for~the~#1~should~be~
-    a~single~non-space~token.
-  }
-  {
-    The~argument~specification~provided~was~not~valid:~in~a~place~
-    where~a~single~token~is~required,~LaTeX~found~'#2'.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { forbidden-implicit-group-token }
-  { Argument~delimiter~'#2'~for~the~#1~is~not~allowed. }
-  {
-    The~argument~specification~provided~was~not~valid:~the~implicit~
-    #3-group~token~'#2'~is~not~allowed~as~an~argument~delimiter.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { processor-in-expandable }
-  { Argument~processor~'>{#2}'~cannot~be~used~for~the~expandable~command~'#1'. }
-  {
-    The~argument~specification~for~#1~contains~a~processor~function:~
-    this~is~only~supported~for~standard~robust~commands.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { too-many-arguments }
-  { Too~many~arguments~in~argument~specification~'#2'~of~#1. }
-  {
-    The~argument~specification~provided~has~more~than~9~arguments.~
-    This~cannot~be~implemented.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { two-markers }
-  { Two~'#2'~apply~to~the~same~argument~in~argument~specification~of~#1. }
-  {
-    The~argument~specification~provided~has~two~markers~'#2'~applying~
-    to~the~same~argument;~these~are~redundant.
-  }
-\__kernel_msg_new:nnnn { xparse } { unknown-argument-type }
-  { Unknown~argument~type~'#2'~for~the~#1. }
-  {
-    The~letter~'#2'~does~not~specify~a~known~argument~type.
-    \c_@@_ignore_def_tl
-  }
-\__kernel_msg_new:nnnn { xparse } { xparse-argument-type }
-  { Deprecated~argument~type~'#2'~for~the~#1~requires~xparse. }
-  {
-    The~letter~'#2'~specifies~a~known~argument~type~that~requires~
-    the~xparse~package.
-    \c_@@_ignore_def_tl
-  }
-%    \end{macrocode}
-%
-% Errors when using commands/environments.  The \texttt{if-boolean}
-% message is always used in expandable errors.  The
-% \texttt{loop-in-defaults} and \texttt{missing-required} messages can
-% be expandable or not expandable.
-%    \begin{macrocode}
-\__kernel_msg_new:nnn { xparse } { if-boolean }
-  { Invalid~use~\iow_char:N\\IfBooleanTF~{#1} }
-\__kernel_msg_new:nnnn { xparse } { loop-in-defaults }
-  { Defaults~of~#1~have~circular~dependency. }
-  {
-    The~default~values~of~two~or~more~arguments~of~the~#1~
-    depend~on~each~other~in~a~way~that~cannot~be~resolved.
-  }
-\__kernel_msg_new:nnnn { xparse } { missing-required }
-  { Missing~required~argument~for~#1. }
-  {
-    The~current~#1~expects~an~argument~starting~with~'#2'.~
-    LaTeX~did~not~find~it,~and~will~insert~a~default~value~to~be~processed.
-  }
-\__kernel_msg_new:nnnn { xparse } { non-xparse }
-  { \str_uppercase:n #1~not~defined~using~xparse. }
-  {
-    You~have~asked~for~the~argument~specification~for~the~#1,~
-    but~this~was~not~defined~using~xparse.
-  }
-\__kernel_msg_new:nnnn { xparse } { split-excess-tokens }
-  { Too~many~'#1'~tokens~when~trying~to~split~argument. }
-  {
-    LaTeX~was~asked~to~split~the~input~'#3'~
-    at~each~occurrence~of~the~token~'#1',~up~to~a~maximum~of~#2~parts.~
-    There~were~too~many~'#1'~tokens.
-  }
-\__kernel_msg_new:nnnn { xparse } { unknown }
-  { Unknown~document~#1. }
-  {
-    You~have~asked~for~the~argument~specification~for~the~#1,~
-    but~it~is~not~defined.
-  }
-\__kernel_msg_new:nnnn { xparse } { verbatim-newline }
-  { Verbatim~argument~of~#1~ended~by~end~of~line. }
-  {
-    The~verbatim~argument~of~the~#1~cannot~contain~more~than~one~line,~
-    but~the~end~
-    of~the~current~line~has~been~reached.~You~may~have~forgotten~the~
-    closing~delimiter.
-    \\ \\
-    LaTeX~will~ignore~'#2'.
-  }
-\__kernel_msg_new:nnnn { xparse } { verbatim-tokenized }
-  { The~verbatim~#1~cannot~be~used~inside~an~argument. }
-  {
-    The~#1~takes~a~verbatim~argument.~
-    It~may~not~appear~within~the~argument~of~another~function.~
-    It~received~an~illegal~token \tl_if_empty:nF {#3} { ~'#3' } .
-    \\ \\
-    LaTeX~will~ignore~'#2'.
-  }
-%    \end{macrocode}
-%
-% Intended more for information.
-%    \begin{macrocode}
-\__kernel_msg_new:nnn { xparse } { define-command }
-  {
-    Defining~command~#1~
-    with~sig.~'#2'~\msg_line_context:.
-  }
-\__kernel_msg_new:nnn { xparse } { define-environment }
-  {
-    Defining~environment~'#1'~
-    with~sig.~'#2'~\msg_line_context:.
-  }
-\__kernel_msg_new:nnn { xparse } { redefine-command }
-  {
-    Redefining~command~#1~
-    with~sig.~'#2'~\msg_line_context:.
-  }
-\__kernel_msg_new:nnn { xparse } { redefine-environment }
-  {
-    Redefining~environment~'#1'~
-    with~sig.~'#2'~\msg_line_context:.
-  }
-\__kernel_msg_new:nnn { xparse } { optional-mandatory }
-  {
-    Since~the~mandatory~argument~'#1'~has~the~same~delimiter~'#2'~
-    as~a~previous~optional~argument,~it~will~not~be~possible~to~
-    omit~all~optional~arguments~when~calling~this~command.
-  }
-\__kernel_msg_new:nnn { xparse } { unsupported-let }
-  {
-    The~command~'#1'~was~undefined~but~not~the~associated~commands~
-    '#1~code'~and/or~'#1~defaults'.~Maybe~you~tried~using~
-    \iow_char:N\\let.~This~may~lead~to~an~infinite~loop.
-  }
-%    \end{macrocode}
-%
-% \subsection{User functions}
-%
-% The user functions are more or less just the internal functions
-% renamed.
-%
-% \begin{macro}{\BooleanFalse}
-% \begin{macro}{\BooleanTrue}
-%   Design-space names for the Boolean values.
-%    \begin{macrocode}
-\cs_new_eq:NN \BooleanFalse \c_false_bool
-\cs_new_eq:NN \BooleanTrue  \c_true_bool
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\NewDocumentCommand}
-% \begin{macro}{\RenewDocumentCommand}
-% \begin{macro}{\ProvideDocumentCommand}
-% \begin{macro}{\DeclareDocumentCommand}
-%   The user macros are pretty simple wrappers around the internal ones.
-%   There is however a check that the first argument is a single token,
-%   possibly surrounded by spaces (hence the strange \cs{use:nnn}), and
-%   is definable.
-%    \begin{macrocode}
-\cs_new_protected:Npn \NewDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \NewDocumentCommand
-      {
-        \cs_if_exist:NTF #1
-          {
-            \__kernel_msg_error:nnxx { xparse } { command-already-defined }
-              { \use:nnn \token_to_str:N #1 { } }
-              { \token_to_str:N \NewDocumentCommand }
-          }
-          { \@@_declare_cmd:Nnn #1 {#2} {#3} }
-      }
-  }
-\cs_new_protected:Npn \RenewDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \RenewDocumentCommand
-      {
-        \cs_if_exist:NTF #1
-          { \@@_declare_cmd:Nnn #1 {#2} {#3} }
-          {
-            \__kernel_msg_error:nnxx { xparse } { command-not-yet-defined }
-              { \use:nnn \token_to_str:N #1 { } }
-              { \token_to_str:N \RenewDocumentCommand }
-          }
-      }
-  }
-\cs_new_protected:Npn \ProvideDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \ProvideDocumentCommand
-      { \cs_if_exist:NF #1 { \@@_declare_cmd:Nnn #1 {#2} {#3} } }
- }
-\cs_new_protected:Npn \DeclareDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \DeclareDocumentCommand
-      { \@@_declare_cmd:Nnn #1 {#2} {#3} }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\NewDocumentEnvironment}
-% \begin{macro}{\RenewDocumentEnvironment}
-% \begin{macro}{\ProvideDocumentEnvironment}
-% \begin{macro}{\DeclareDocumentEnvironment}
-%   Very similar for environments.
-%    \begin{macrocode}
-\cs_new_protected:Npn \NewDocumentEnvironment #1#2#3#4
-  {
-    \cs_if_exist:cTF {#1}
-      { \__kernel_msg_error:nnx { xparse } { environment-already-defined } {#1} }
-      { \@@_declare_env:nnnn {#1} {#2} {#3} {#4} }
-  }
-\cs_new_protected:Npn \RenewDocumentEnvironment #1#2#3#4
-  {
-    \cs_if_exist:cTF {#1}
-      { \@@_declare_env:nnnn {#1} {#2} {#3} {#4} }
-      { \__kernel_msg_error:nnx { xparse } { environment-not-yet-defined } {#1} }
-  }
-\cs_new_protected:Npn \ProvideDocumentEnvironment #1#2#3#4
-  { \cs_if_exist:cF {#1} { \@@_declare_env:nnnn {#1} {#2} {#3} {#4} } }
-\cs_new_protected:Npn \DeclareDocumentEnvironment #1#2#3#4
-  { \@@_declare_env:nnnn {#1} {#2} {#3} {#4} }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\NewExpandableDocumentCommand}
-% \begin{macro}{\RenewExpandableDocumentCommand}
-% \begin{macro}{\ProvideExpandableDocumentCommand}
-% \begin{macro}{\DeclareExpandableDocumentCommand}
-%   The expandable versions are essentially the same as the basic
-%   functions.  The strange \cs{use:nnn} is there in case |#1| is
-%   surrounded with spaces, as can happen with usual document catcodes
-%   in \cs{RenewExpandableDocumentCommand} |{| |\!| |}| \ldots{}
-%    \begin{macrocode}
-\cs_new_protected:Npn \NewExpandableDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \NewExpandableDocumentCommand
-      {
-        \cs_if_exist:NTF #1
-          {
-            \__kernel_msg_error:nnxx { xparse } { command-already-defined }
-              { \use:nnn \token_to_str:N #1 { } }
-              { \token_to_str:N \NewExpandableDocumentCommand }
-          }
-          { \@@_declare_expandable_cmd:Nnn #1 {#2} {#3} }
-      }
-  }
-\cs_new_protected:Npn \RenewExpandableDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \RenewExpandableDocumentCommand
-      {
-        \cs_if_exist:NTF #1
-          { \@@_declare_expandable_cmd:Nnn #1 {#2} {#3} }
-          {
-            \__kernel_msg_error:nnxx { xparse } { command-not-yet-defined }
-              { \use:nnn \token_to_str:N #1 { } }
-              { \token_to_str:N \RenewExpandableDocumentCommand }
-          }
-      }
-  }
-\cs_new_protected:Npn \ProvideExpandableDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \ProvideExpandableDocumentCommand
-      {
-        \cs_if_exist:NF #1
-          { \@@_declare_expandable_cmd:Nnn #1 {#2} {#3} }
-      }
- }
-\cs_new_protected:Npn \DeclareExpandableDocumentCommand #1#2#3
-  {
-    \@@_check_definable:nNT {#1} \DeclareExpandableDocumentCommand
-      { \@@_declare_expandable_cmd:Nnn #1 {#2} {#3} }
-  }
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-% \begin{macro}{\IfBooleanT, \IfBooleanF, \IfBooleanTF}
-%   The logical \meta{true} and \meta{false} statements are just the
-%   normal \cs{c_true_bool} and \cs{c_false_bool} so \cs{bool_if:NTF} is
-%   almost enough.  However, this code-level function blows up badly
-%   when passed invalid input.  We want \cs{IfBooleanTF} to accept a
-%   single (non-space) token equal to \cs{c_true_bool} or
-%   \cs{c_false_bool}, possibly surrounded by spaces.  If the input is
-%   blank or multiple items, jump to the error and pick the false
-%   branch.  If the input, ignoring spaces (we do this by omitting
-%   braces in the \cs{tl_if_single_token:nF} test), is not a single
-%   token then jump to the error as well.  It is then safe to compare
-%   the token to the two booleans, picking the appropriate branch.  If
-%   neither matches, we jump to the error as well.
-%    \begin{macrocode}
-\cs_new:Npn \IfBooleanTF #1
-  {
-    \tl_if_single:nF {#1}
-      { \prg_break:n { \use:n } }
-    \tl_if_single_token:nF #1
-      { \prg_break:n { \use:n } }
-    \token_if_eq_meaning:NNT #1 \c_true_bool
-      { \prg_break:n { \use_ii:nnn } }
-    \token_if_eq_meaning:NNT #1 \c_false_bool
-      { \prg_break:n { \use_iii:nnn } }
-    \prg_break:n { \use:n }
-    \prg_break_point:
-    {
-      \__kernel_msg_expandable_error:nnn { xparse } { if-boolean } {#1}
-      \use_ii:nn
-    }
-  }
-\cs_new:Npn \IfBooleanT #1#2 { \IfBooleanTF {#1} {#2} { } }
-\cs_new:Npn \IfBooleanF #1 { \IfBooleanTF {#1} { } }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\IfNoValueT, \IfNoValueF, \IfNoValueTF}
-%   Simple re-naming.
-%    \begin{macrocode}
-\cs_new_eq:NN \IfNoValueF  \tl_if_novalue:nF
-\cs_new_eq:NN \IfNoValueT  \tl_if_novalue:nT
-\cs_new_eq:NN \IfNoValueTF \tl_if_novalue:nTF
-%    \end{macrocode}
-% \end{macro}
-% \begin{macro}{\IfValueT, \IfValueF, \IfValueTF}
-%   Inverted logic.
-%    \begin{macrocode}
-\cs_new:Npn \IfValueF { \tl_if_novalue:nT }
-\cs_new:Npn \IfValueT { \tl_if_novalue:nF }
-\cs_new:Npn \IfValueTF #1#2#3 { \tl_if_novalue:nTF {#1} {#3} {#2} }
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\ProcessedArgument}
-%   Processed arguments are returned using this name, which is reserved
-%   here although the definition will change.
-%    \begin{macrocode}
-\tl_new:N \ProcessedArgument
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\ReverseBoolean, \SplitArgument, \SplitList, \TrimSpaces}
-%   Simple copies.
-%    \begin{macrocode}
-\cs_new_eq:NN \ReverseBoolean \@@_bool_reverse:N
-\cs_new_eq:NN \SplitArgument  \@@_split_argument:nnn
-\cs_new_eq:NN \SplitList      \@@_split_list:nn
-\cs_new_eq:NN \TrimSpaces     \@@_trim_spaces:n
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\ProcessList}
-%   To support \cs{SplitList}.
-%    \begin{macrocode}
-\cs_new_eq:NN \ProcessList \tl_map_function:nN
-%    \end{macrocode}
-% \end{macro}
-%
-% \begin{macro}{\GetDocumentCommandArgSpec}
-% \begin{macro}{\GetDocumentEnvironmentArgSpec}
-% \begin{macro}{\ShowDocumentCommandArgSpec}
-% \begin{macro}{\ShowDocumentEnvironmentArgSpec}
-%   More simple mappings, with a check that the argument is a single
-%   control sequence or active character.
-%    \begin{macrocode}
-\cs_new_protected:Npn \GetDocumentCommandArgSpec #1
-  {
-    \@@_check_definable:nNT {#1} \GetDocumentCommandArgSpec
-      { \@@_get_arg_spec:N #1 }
-  }
-\cs_new_eq:NN \GetDocumentEnvironmentArgSpec \@@_get_arg_spec:n
-\cs_new_protected:Npn \ShowDocumentCommandArgSpec #1
-  {
-    \@@_check_definable:nNT {#1} \ShowDocumentCommandArgSpec
-      { \@@_show_arg_spec:N #1 }
-  }
-\cs_new_eq:NN \ShowDocumentEnvironmentArgSpec \@@_show_arg_spec:n
-%    \end{macrocode}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-% \end{macro}
-%
-%    \begin{macrocode}
-\@@_file_end_hook:
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%</core>
-%    \end{macrocode}
-%
-%    \begin{macrocode}
-%<*2ekernel>
-\ExplSyntaxOff
-%</2ekernel>
+%</package>
 %    \end{macrocode}
 %
 % \end{implementation}
diff --git a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.ins b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.ins
index 17a94782a46..da55996744b 100644
--- a/Master/texmf-dist/source/latex/l3packages/xparse/xparse.ins
+++ b/Master/texmf-dist/source/latex/l3packages/xparse/xparse.ins
@@ -2,7 +2,7 @@
 
 File: xparse.ins
 
-Copyright (C) 2000-2012,2016,2017,2019,2020 The LaTeX3 Project
+Copyright (C) 2000-2012,2016,2017,2019-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of the
 LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -23,7 +23,7 @@ The released version of this bundle is available from CTAN.
 
 \preamble
 
-Copyright (C) 2009-2020 The LaTeX3 Project
+Copyright (C) 2009-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of
 the LaTeX Project Public License (LPPL), either version 1.3c of
@@ -42,8 +42,7 @@ and all files in that bundle must be distributed together.
 
 \keepsilent
 
-\generate{\file{xparse-generic.tex}{\from{xparse.dtx}{core}}
-          \file{xparse.sty}{\from{xparse.dtx}{package}}
+\generate{\file{xparse.sty}{\from{xparse.dtx}{package}}
           \file{xparse.ltx}{\from{xparse.dtx}{2ekernel}}}
 
 \endbatchfile
diff --git a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
index 7ea561b199e..a20b55892e2 100644
--- a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
+++ b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.dtx
@@ -3,8 +3,8 @@
 %% File: xtemplate.dtx
 %
 % Copyright (C) 1999 Frank Mittelbach, Chris Rowley, David Carlisle
-%           (C) 2004-2010 Frank Mittelbach, The LaTeX3 Project
-%           (C) 2011-2020 The LaTeX3 Project
+%           (C) 2004-2010 Frank Mittelbach, The LaTeX Project
+%           (C) 2011-2021 The LaTeX Project
 %
 % It may be distributed and/or modified under the conditions of the
 % LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -55,7 +55,7 @@
 % }
 %
 % \author{^^A
-%  The \LaTeX3 Project\thanks
+%  The \LaTeX{} Project\thanks
 %    {^^A
 %      E-mail:
 %        \href{mailto:latex-team@latex-project.org}
@@ -63,7 +63,7 @@
 %    }^^A
 % }
 %
-% \date{Released 2020-10-27}
+% \date{Released 2021-02-02}
 %
 % \maketitle
 %
@@ -682,7 +682,7 @@
 %    \end{macrocode}
 %
 %    \begin{macrocode}
-\ProvidesExplPackage{xtemplate}{2020-10-27}{}
+\ProvidesExplPackage{xtemplate}{2021-02-02}{}
   {L3 Experimental prototype document functions}
 %    \end{macrocode}
 %
diff --git a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.ins b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.ins
index 43dfb266206..3e88b5e52c4 100644
--- a/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.ins
+++ b/Master/texmf-dist/source/latex/l3packages/xtemplate/xtemplate.ins
@@ -2,7 +2,7 @@
 
 File: xtemplate.ins
 
-Copyright (C) 2000-2012,2016,2017,2019,2020 The LaTeX3 Project
+Copyright (C) 2000-2012,2016,2017,2019-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of the
 LaTeX Project Public License (LPPL), either version 1.3c of this
@@ -34,7 +34,7 @@ license information is placed in the derived files.
 
 \preamble
 
-Copyright (C) 2011-2020 The LaTeX3 Project
+Copyright (C) 2011-2021 The LaTeX Project
 
 It may be distributed and/or modified under the conditions of
 the LaTeX Project Public License (LPPL), either version 1.3c of