% \iffalse meta-comment
%
% Copyright (C) 2023-20** by Romain NOEL <romainoel@free.fr>
% -----------------------------------------------------------
%
% This file may be distributed and/or modified under the conditions of
% the LaTeX Project Public License, either version 1.3c of this license
% or (at your option) any later version. The latest version of this
% license is in:
%
% http://www.latex-project.org/lppl.txt
%
% and version 1.3c or later is part of all distributions of LaTeX
% version 2006/05/20 or later.
%
% \fi
%
% \iffalse
%<*driver>
\ProvidesFile{tensorstyles.dtx}
%</driver>
%<*internal>
\input expl3-generic \relax
%</internal>
%<class>\NeedsTeXFormat{LaTeX3e}
%<package>\ProvidesExplPackage{tensorstyles}{2026-04-28}{1.0.1.4}{This package provides a generic customable display of tensors.}
%<author>Romain NOEL</author>
%<maintainer>Romain NOEL</maintainer>
%<url>https://gitlab.com/RomainNOEL/tensorstyles</url>
%<desc>
% This package let you display your tensors according to their order in a generic way. This let you choose and change options of display according to the context.
% </desc>
%
%<*driver>
\documentclass{l3doc}
	\usepackage[T1]{fontenc}
	\usepackage{pdfpages}
	\usepackage{standalone}
	\usepackage{tensorstyles}
	% \usepackage{readprov}
	% 	\ReadPackageInfos{tensorstyles}
	\edef\tensorstylesVersion{v1.0.1.4} %{\fileversion}
	\edef\tensorstylesDate{2026-04-28} %{\filedate}

	\usepackage{parskip}
	\usepackage{setspace}
	\usepackage{xspace}
		\onehalfspacing

	\usepackage{xcolor}
		\definecolor{tPrim}{HTML}{00707F}   % Green-Blue
		\definecolor{tSec}{HTML}{5FA4B0}    % Green-Blue light
		\definecolor{tAccent}{HTML}{F07F3C} % Orange
		\definecolor{tGrey}{HTML}{E6E6E1}   % Grey-Beige

	% \usepackage{fancyvrb}
	\usepackage{listings}
		\lstset{
			language=[LaTeX]{TeX},
			basicstyle=\ttfamily,
			keywordstyle=\color{tPrim}\bfseries,
			commentstyle=\color{tSec},
			stringstyle=\color{tSec},
			backgroundcolor=\color{white},
			numbers=none,
			numberstyle=\tiny\ttfamily,
			stepnumber=2,
			showspaces=false,
			showstringspaces=false,
			showtabs=false,
			frame=none,
			framerule=1pt,
			tabsize=2,
			rulesep=5em,
			captionpos=b,
			breaklines=true,
			breakatwhitespace=false,
			framexleftmargin=0em,
			framexrightmargin=0em,
			xleftmargin=0em,
			xrightmargin=0em,
			aboveskip=1em,
			belowskip=1em,
			morekeywords={plain,tensorsset},
		}
		\lstMakeShortInline|

	\usepackage{hyperref}
		\setlength{\fboxsep}{0pt}%
	\usepackage{subcaption} % For subfigures
	\usepackage{cleveref} % for references

		\providecommand{\defopt}[1]{\underline{#1}}%{default: #1}%
		\NewDocumentEnvironment{DescribetensorstylesOption}{ o m m m }{
			% At beginning of the environment
			\DescribeOption{#2} % from l3doc
			\IfNoValueTF{#1}{
				% true => left empty intentionally
			}{
				%false
				\DescribeOption{
					% add extra info like added or updated dates to mimic 'function' env.
					\rule[2.5ex]{\linewidth}{0.3pt}
					\\[-3.5ex]
					{\scriptsize #1 \hfill\ }
				}
			}
			\begin{minipage}[t]{\textwidth}
				\textit{\textbf{\textcolor{tSec}{#3}}}\dotfill\,\defopt{#4}\par
				\begingroup
					\vspace{0.5em}
		}{
			% At environment's end
					\par
				\endgroup
			\end{minipage}
		}


	%% =====================================================================
	\title{\textsc{ tensorstyles }\\
		This package provides a generic customable display of tensors.
	}
	\author{Romain NOEL \\ \url{romainoel@free.fr}}
	\date{\tensorstylesVersion~---~\tensorstylesDate}

	\providecommand{\pkgName}{\textbf{\textsc{tensorstyles}}\xspace}

	%% =====================================================================


	%% l3doc commands
	\EnableCrossrefs
	\CodelineIndex
	\RecordChanges
\begin{document}
\input{tensorstyles-doc.tex}
	\clearpage
%\section{A simple example}
% \includepdf[pages=-,
% 	pagecommand=\section{A simple example},
% 	width=0.7\textwidth]
% 	{tensorstyles-exampleSimple.pdf}
\section{Commands description for users}
	\EnableDocumentation
	\DisableImplementation
	\DocInput{\jobname.dtx}
	\newpage
\section{Package implementation for developers}
	\EnableImplementation
	\DisableDocumentation
	\GetFileInfo{\jobname.sty}
	\DocInput{\jobname.dtx}
	\PrintChanges
\end{document}
%</driver>
%
%<*devImpl>
\documentclass{l3doc}
	\usepackage[T1]{fontenc}
	\usepackage{pdfpages}
	\usepackage{standalone}
	\usepackage{tensorstyles}
	\providecommand{\defopt}[1]{\underline{#1}}
	% l3doc commands
	\EnableCrossrefs
	\CodelineIndex
	\RecordChanges
\begin{document}
\section{Commands description for users}
	\EnableImplementation
	\DisableDocumentation
	\DocInput{tensorstyles.dtx}
\end{document}
%</devImpl>
%
%
%<*userCmd>
\documentclass{l3doc}
	\usepackage[T1]{fontenc}
	\usepackage{pdfpages}
	\usepackage{standalone}
	%\usepackage{tensorstyles}
	\providecommand{\defopt}[1]{\underline{#1}}
	% l3doc commands
	\EnableCrossrefs
	\CodelineIndex
	\RecordChanges
\begin{document}
\section{Package implementation for developers}
	\EnableDocumentation
	\DisableImplementation
	\DocInput{tensorstyles.dtx}
\end{document}
%</userCmd>
%
% \fi
%
%
% \begin{implementation}
%    \begin{macrocode}
%<*package>
%\ProvidesExplPackage{tensorstyles}{2026-04-28}{1.0.1.4}{This package provides a generic customable display of tensors.}
\RequirePackage{expl3}
% \RequirePackage{xparse,l3keys2e}% depreciated now.
\RequirePackage{amsmath}% \overrightarrow
\RequirePackage{amssymb}% \curvearrowright
% \RequirePackage{bm}% recommended for bold math
\RequirePackage{mathtools}% for \mathmakebox
%    \end{macrocode}
% \end{implementation}
%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%   PACKAGE   %%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% \begin{implementation}
% 	\begin{variable}{\c__tensorstyles_digits_tl}
%		Constant variables containing the digits.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
%    \begin{macrocode}
\tl_const:Nn \c__tensorstyles_digits_tl {123456789-0}
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{documentation}
% 	\begin{macro}{\usepackage[options]{tensorstyles}}
%  	\begin{syntax}
% 			\cs{usepackage{}}\oarg{option1=value1, ...}\marg{tensorstyles}
% 			\textrm{where the options are (default marked as} \defopt{default}\textrm{):}
% 			\meta{footer template} = \oarg{\defopt{tensorstyles} \textbar ... }
% 		\end{syntax}
% 		Description of |usepackage{tensorstyles}| which loads the package.
% 	\end{macro}
% \end{documentation}
%%%%
% \begin{implementation}
% 	\begin{macro}{\usepackage[options]{tensorstyles} }
% 		\begin{arguments}
% 			\item |no package option| are present for now.
% 		\end{arguments}
% 		Description
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\UnitTested
% 		\TestFiles{tensorstyles-test-003}
%    \begin{macrocode}
% Define keys/options for the package.
\keys_define:nn { tensorstyles / pkg }
{
	% italic .choice:,
	% italic .usage:n = { load },
	% italic .default:n = { true },
	% italic / true .code:n =
	% {
	% 	\bool_set_true:N  \l__tensorstyles_pkg_italic_bool
	% 	\bool_set_false:N \l__tensorstyles_pkg_upright_bool
	% },
	% italic / false .code:n =
	% {
	% 	\bool_set_false:N \l__tensorstyles_pkg_italic_bool
	% 	\bool_set_true:N  \l__tensorstyles_pkg_upright_bool
	% },
	% italic / unknown .code:n = { \msg_error:nnx { tensorstyles } { boolean-values-only } \l_keys_key_str },
	% %
	% upright .choice:,
	% upright .usage:n = { load },
	% upright .default:n = { true },
	% upright / true .code:n =
	% {
	% 	\bool_set_true:N  \l__tensorstyles_pkg_upright_bool
	% 	\bool_set_false:N \l__tensorstyles_pkg_italic_bool
	% },
	% upright / false .code:n =
	% {
	% 	\bool_set_false:N \l__tensorstyles_pkg_upright_bool
	% 	\bool_set_true:N  \l__tensorstyles_pkg_italic_bool
	% },
	% upright / unknown .code:n = { \msg_error:nnx { tensorstyles } { boolean-values-only } \l_keys_key_str },
	% upright .initial:n = true,
}
% process the options.
\ProcessKeyOptions[ tensorstyles / pkg ]
%    \end{macrocode}
% 	\end{macro}
% \end{implementation}


%%%%%%  Key-val: tensorstyles %%%%%%

% \begin{implementation}
% 	\begin{variable}{\l__tensorstyles_all_all_user_keys_prop, \c__tensorstyles_all_pkg_keys_prop}
% 		Property list containing the default value for options that are share by all command groups; and a list that will receive the values given by users for these options.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-003}
%    \begin{macrocode}
\prop_const_from_keyval:Nn \c__tensorstyles_all_pkg_keys_prop {scale-auto = leftright}
\prop_new:N \l__tensorstyles_all_all_user_keys_prop
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{documentation}
% 	\begin{macro}{\tensorsset{all}[options]}
%  	\begin{syntax}
% 			\cs{nameMacro}\oarg{option1=value1, ...}\marg{tensor-cmd}
% 			\textrm{where the options are (default marked as} \defopt{default}\textrm{):}
% 			\meta{scale-auto} = \oarg{\defopt{leftright} \textbar auto }
% 		\end{syntax}
% 		The option |scale-auto| that can be set for all command groups, can take |leftright| or |mleftmright| values.
% 		This option is controlling the delimiters to use in auto mode (|\left\right| or |\mleft| |\mright| from |mleftright| package).
% 	\end{macro}
% \end{documentation}
%%%%
% \begin{implementation}
% 	\begin{macro}{\tensorsset{all}[options]}
% 		\begin{arguments}
% 			\item |width| Name of the option to add, this name should also correspond to the name of the environment followed by the suffix 'env'.
% 		\end{arguments}
% 		Option available for all command groups controlling the delimiters in automatic scale mode.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\UnitTested
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% Define the options for all group commands (package included).
\keys_define:nn { tensorstyles / all / all } {
	scale-auto .choice:,
	scale-auto / leftright .code:n =	{
		\cs_set_eq:NN \__tensorstyles_auto_left:n \left
		\cs_set_eq:NN \__tensorstyles_auto_right:n \right
	},
	scale-auto / mleftmright .code:n = {
		\cs_set_nopar:Npn \__tensorstyles_auto_left:n  { \mleft  }
		\cs_set_nopar:Npn \__tensorstyles_auto_right:n { \mright }
	}
}
%    \end{macrocode}
% 	\end{macro}
% \end{implementation}

% \begin{implementation}
% 	\begin{variable}{\l__tensorstyles_new_var_seq}
%		Local sequence storing new variables names to create.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
%    \begin{macrocode}
\seq_new:N \l__tensorstyles_new_var_seq
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_new}
% 		\begin{arguments}
% 			\item |variable-type| eg. "tl" (token list), "dim", "seq", etc.
%  		\item |grp-cmd+variant| eg. "$tensor_tensor$"
%  		\item |variable-category| eg. "style"
%  		\item |cs-var-list| comma separated list of variable names to create.
% 		\end{arguments}
% 		This function is creating the local variables |\l__tensorstyles_'type'_'variant'_'cat'_'var'| for all the variable names given in the argument 4 (|cs-var-list|).
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\cs_new:Npn \__tensorstyles_new:nnnn #1 #2 #3 #4 {
	\seq_set_from_clist:Nn \l__tensorstyles_new_var_seq { #4 }
	\seq_map_inline:Nn \l__tensorstyles_new_var_seq
	{ \cs:w #1_new:c \cs_end: { l__tensorstyles_#2_#3_##1_#1 } }
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

%
% %%%%%  Setting keys  %%%%%
%
% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_set_default_from_keyval}
% 		\begin{arguments}
% 			\item |variable-type| eg. tl (token list), dim, seq etc.
%  		\item |preset| eg. preset
%  		\item |keyval| the option given
%  		\item |cs-var-list| comma separated list of variable names to create.
% 		\end{arguments}
% 		This function is setting the default keys/options from a list of keyval.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \__tensorstyles_set_default_from_keyval: variant, preset, keyval,  group command
\cs_new_protected:Npn \__tensorstyles_set_default_from_keyval:nnnn #1 #2 #3 #4 {
	% tensorstyles~set~default~from~keyval
	% Check if keyvalues have been given.
	\tl_if_novalue:nTF { #3 }
	{ % no user keys given so _user_keys_prop is taking pkg prop
		\prop_set_eq:cc { l__tensorstyles_#4_#1_user_keys_prop } { c__tensorstyles_#4_#2_pkg_keys_prop }
	}{ % user key given and put it in prop
		\prop_put_from_keyval:cn { l__tensorstyles_#4_#1_user_keys_prop } { #3 }
	}% end if
	%
	% prepare the map of keys
	\__tensorstyles_set_default_auxi:cnn { l__tensorstyles_#4_#1_user_keys_prop } { #1 } { #4 }
	%
	% set this map as default
	\keys_set:nn { tensorstyles/#4/#1 } { default }
}
\cs_generate_variant:Nn \__tensorstyles_set_default_from_keyval:nnnn { nVnn }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_set_default_auxi, \__tensorstyles_set_default_auxii}
% 		\begin{arguments}
% 			\item |prop-key-val| eg. tl (token list), dim, seq etc.
%  		\item |variant| eg. 'options=toto'
%  		\item |grp-cmd| eg. "style"
% 		\end{arguments}
% 		These functions are internally used to set the default keys/options.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\cs_new_protected:Npn \__tensorstyles_set_default_auxi:Nnn #1 #2 #3 {
	\__tensorstyles_set_default_auxii:fnn { \prop_to_keyval:N #1 } { #2 } { #3 }
}
\cs_generate_variant:Nn \__tensorstyles_set_default_auxi:Nnn { c }
%
% key-val, variant,  group command
\cs_new_protected:Npn \__tensorstyles_set_default_auxii:nnn #1 #2 #3 {
	\keys_define:nn { tensorstyles/#3/#2 } { default .meta:n = { #1 } }
}
\cs_generate_variant:Nn \__tensorstyles_set_default_auxii:nnn { f }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\tensorsset}
% 		\begin{arguments}
% 			\item |command| for which options will be set or reset.
%  		\item |options| input given as setting options.
% 		\end{arguments}
% 		Function to (re)set keys/options by default for a group of commands.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \tensorsset m:command:#1 o:options:#2
\DeclareDocumentCommand{\tensorsset}{ m o } {
	\str_if_eq:nnTF { #1 } { all }
	{
		% True: if the 'all' commands have to be set.
		\__tensorstyles_set_default_from_keyval:nnnn { all } {empty} { #2 } { all }
		\keys_set:nn { tensorstyles/all/all } { default }
	}{
		%False: if the command name is given then apply to it:
		% capture the command name.
		\tl_set:Nx \l__tensorstyles_tensorsset_tl { \cs_to_str:N #1 }
		% apply option to the command.
		\tensorstyles_set_keys:Vn \l__tensorstyles_tensorsset_tl { #2 }
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\tensorstyles_local_keys}
% 		\begin{arguments}
% 			\item |keyval| for which options will be set or reset.
%  		\item |grp-cmd| input given as setting options.
%  		\item |command| input given as setting options.
%  		\item |preset| of options.
% 		\end{arguments}
% 		Set options according to the keys-value given by the user locally.
% 		This command is used in the code definition of the 'command'-group, ie., is called every time the 'command' is called.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% tensorstyles_local_keys:nnnn #1=keyval, #2=group-command, #3=command, #4=preset
\cs_new_protected:Npn \tensorstyles_local_keys:nnnn #1 #2 #3 #4 {
	% in tensorstyles~local~keys
	\tl_set:Ne \l_tmpa_tl { #4 }

	\tl_if_novalue:nTF { #1 }
	{
		% keyval NOT given
		\bool_if:cT { l__tensorstyles_#2_#3_local_keys_bool }
		{
			% True
			\keys_set:nV { tensorstyles/#2/#3 } \l_tmpa_tl
			\bool_set_false:c { l__tensorstyles_#2_#3_local_keys_bool }
		}
	}{
		% keyvalue given
		\bool_if:cTF { l__tensorstyles_#2_#3_local_keys_bool }
		{
			% True
			\tl_put_right:Nn \l_tmpa_tl { , #1 }  % append #1 unexpanded
			\keys_set:nV { tensorstyles/#2/#3 } \l_tmpa_tl
		}{
			% False
			\tl_put_right:Nn \l_tmpa_tl { , #1 }  % append #1 unexpanded
			\keys_set:nV { tensorstyles/#2/#3 } \l_tmpa_tl
		}
		\bool_set_true:c { l__tensorstyles_#2_#3_local_keys_bool }
	}
}
\cs_generate_variant:Nn \keys_set:nn { nV }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\tensorstyles_local_preset }
% 		\begin{arguments}
% 			\item |keyval| for which options will be set or reset.
%  		\item |grp-cmd| input given as setting options.
%  		\item |preset| of options.
%  		\item |variant| of options.
% 		\end{arguments}
% 		Set options according to the keys-value given by the user locally.
% 		This command is used in the code definition of the 'command'-group, ie., is called every time the 'command' is called.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% tensorstyles_local_preset:nnn #1=group-command, #2=preset, #3=star-preset #4=variant
\cs_new_protected:Npn \tensorstyles_local_preset:nVVnn #1 #2 #3 #4 {
	\tl_if_eq:NnTF { #2 } { None } {
		\keys_define:nn { tensorstyles/tensor/#1 } { pres .meta:n = { default }}
	} {
		\prop_set_eq:cc { l__tensorstyles_#4_#1_user_keys_prop } { c__tensorstyles_#4_#2_pkg_keys_prop }
		\keys_define:nn { tensorstyles/tensor/#1 } {
			pres .code:n = {
				\prop_map_inline:cn { l__tensorstyles_#4_#1_user_keys_prop }
					{ \keys_set:nn { tensorstyles/tensor/#1 } { ####1 = {####2} } }
			}
		}
	}
	\tl_if_eq:NnTF { #3 } { None } {
		\keys_define:nn { tensorstyles/tensor/#1 } { pres* .meta:n = { default }}
	} {
		\prop_set_eq:cc { l__tensorstyles_#4_#1*_user_keys_prop } { c__tensorstyles_#4_#3_pkg_keys_prop }
		\keys_define:nn { tensorstyles/tensor/#1 } {
			pres* .code:n = {
				\prop_map_inline:cn { l__tensorstyles_#4_#1*_user_keys_prop }
					{ \keys_set:nn { tensorstyles/tensor/#1 } { ####1* = {####2} } }
			}
		}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\tensorstyles_addto_globalvar_and_setkeys:NNnnn}
% 		\begin{arguments}
%  		\item |tl-tensor| token list used to concatenate the name of the command.
%  		\item |macro| input given as setting options.
%  		\item |command| input given as setting options.
% 			\item |keyval| for which options will be set or reset.
%  		\item |grp-cmd| input given as setting options.
% 		\end{arguments}
% 		Set options according to the keys-value given by the user locally.
% 		This command is used in the code definition of the 'command'-group, ie., is called every time the 'command' is called.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%
% \tensorstyles_addto_globalvar_and_setkeys:NNnnn #1=tl-tensor, #2=macro, #3=inf, #4=keyval, #5=group command
\cs_new_protected:Npn \tensorstyles_addto_globalvar_and_setkeys:NNnnn #1 #2 #3 #4 #5 {
	% store
	\tl_set:Nx #1 { \cs_to_str:N #2 }

	% Check if the keyval has values.
	\tl_if_novalue:nTF { #4 }
	{
		% if empty then create the variables by default.
		\__tensorstyles_preamble_aux:Vnnnn #1 { empty } { empty } { } { #5 }
	}{
		% otherwise, create then set the variables.
		\use:c { __tensorstyles_#5_define_preset_keys:n } { #1 }
		\keys_set:nn {tensorstyles/preset/#1} { #4 }
		\tl_set:Nx \l_tmpa_tl { \tl_use:c { l__tensorstyles_tensor_#1_preset  } }
		\tl_set:Nx \l_tmpb_tl { \tl_use:c { l__tensorstyles_tensor_#1*_preset } }

		\__tensorstyles_preamble_aux:VVVnn #1 \l_tmpa_tl \l_tmpb_tl { #4 } { #5 }
		% \__tensorstyles_preamble_aux:Veenn #1 { full } { empty } { #4 } { #5 }
	}

}
%
% \__tensorstyles_preamble_aux:nnnn #1=variant, #2=preset, #3=star-preset, #4=key-value, #5=grp-cmd
\cs_new_protected:Npn \__tensorstyles_preamble_aux:nnnnn #1 #2 #3 #4 #5 {
	% Check if the command is in the global sequence
	\seq_if_in:cnF { l__tensorstyles_#5_variant_seq } { #1 }
	{

		% if not present
		% add the command to the sequence
		\seq_put_left:cn { l__tensorstyles_#5_variant_seq } { #1 }
		% create new variables (tl) for the new command
		\use:c { __tensorstyles_#5_variables:n   } { #1 }
		\use:c { __tensorstyles_#5_variables:n   } { #1* }
		% define keys for this command
		\use:c { __tensorstyles_#5_define_keys:n } { #1 }
		\use:c { __tensorstyles_#5_define_keys:n } { #1* }
	}

	% Apply package options
	\prop_set_eq:cc { l__tensorstyles_#5_#1_user_keys_prop } { c__tensorstyles_#5_#2_pkg_keys_prop }
	\prop_set_eq:cc { l__tensorstyles_#5_#1*_user_keys_prop } { c__tensorstyles_#5_#3_pkg_keys_prop }
	% Apply the newly given options by default
	\__tensorstyles_set_default_from_keyval:nnnn { #1* } { #3 } { } { #5 }
	\__tensorstyles_set_default_from_keyval:nnnn { #1 } { #2 } { #4 } { #5 }
}
\cs_generate_variant:Nn \__tensorstyles_preamble_aux:nnnnn { VVVnn }
\cs_generate_variant:Nn \__tensorstyles_preamble_aux:nnnnn { V }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

%
%
%%%%%%  'TENSOR' GROUP COMMAND CODE  %%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \begin{implementation}
% 	\begin{variable}[added= 2025-02-17]{\l__tensorstyles_tensor_variant_seq, \l__tensorstyles_tensor_rank_holder_tl, \l__tensorstyles_tensor_rank_counter_int}
% 		|\l__tensorstyles_tensor_variant_seq| is a sequence to store all the command of this type.
% 		|\l__tensorstyles_tensor_rank_holder_tl| is storing the value of the tensor rank given.
% 		|\l__tensorstyles_tensor_rank_counter_int| is storing the local value of the rank counter (as Einstein indices are running for example).
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
%    \begin{macrocode}
\seq_new:N \l__tensorstyles_tensor_variant_seq
\tl_new:N \l__tensorstyles_tensor_rank_holder_tl
\int_new:N \l__tensorstyles_tensor_rank_counter_int
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_tensor_variables:n}
% 		\begin{arguments}
%  		\item |variant| for which variables have to be declared.
% 		\end{arguments}
% 		Define variables of the `tensor` command-group, according to the keys-value given by the user locally.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% Define variables for the tensor group.
% \__tensorstyles_tensor_variables:n variant
\cs_new_protected:Npn \__tensorstyles_tensor_variables:n #1 {
	%%\__tensorstyles_new:nnnn data-type, grp-cmd+variant, category, cs-var-list
	%
	% switch
	\__tensorstyles_new:nnnn { bool } {tensor_#1} { switch } { star }
	\__tensorstyles_new:nnnn { bool } {tensor_#1} { switch } { font, einstein, dirac, arrows, recursiveArrows } %
	% font
	\__tensorstyles_new:nnnn { prop } {tensor_#1} { font } { cmd }
	% Einstein
	\__tensorstyles_new:nnnn { tl } {tensor_#1} { indexstyle } { covariant, contra }
	% arrows
	\__tensorstyles_new:nnnn { prop } {tensor_#1} { arrow } { cmd }
	% recursive arrows
	\__tensorstyles_new:nnnn { tl } {tensor_#1} { recursive } { arrowCmd }
	% Dirac bra-ket
	\__tensorstyles_new:nnnn { tl } {tensor_#1} { scale  } { var }
	\__tensorstyles_new:nnnn { tl } {tensor_#1} { delims } { eval }
	% keys
	\__tensorstyles_new:nnnn { prop } {tensor_#1} { user  } { keys }
	\__tensorstyles_new:nnnn { bool } {tensor_#1} { local } { keys }
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{macro}[added= 2025-02-17]{\__tensorstyles_tensor_define_keys:n}
% 		\begin{arguments}
%  		\item |variant| for which key corresponding the command associated, have to be declared.
% 		\end{arguments}
% 		Set options for the `tensor` group-command according to the keys-value given by the user locally.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% Define keys/options for tensor group command style.
% \__tensorstyles_tensor_define_keys:n variant
\cs_new:Npn \__tensorstyles_tensor_define_keys:n #1 {
	\keys_define:nn { tensorstyles/tensor/#1 } {
		switch-* .bool_set:c = { l__tensorstyles_tensor_#1_switch_star_bool },
		preset .code:n = {},
		deduce-var .tl_set:c = { l__tensorstyles_tensor_#1_deduce_var_tl },

		% font
		font .bool_set:c = { l__tensorstyles_tensor_#1_switch_font_bool },
		font-cmd .code:n = { \prop_set_from_keyval:cn { l_tensorstyles_tensor_#1_font_cmd_prop } {##1} },

		% arrow
		arrows .bool_set:c = { l__tensorstyles_tensor_#1_switch_arrows_bool },
		arrow-cmd .code:n = { \prop_set_from_keyval:cn { l_tensorstyles_tensor_#1_arrow_cmd_prop } {##1} },

		recursive-arrows .bool_set:c = { l__tensorstyles_tensor_#1_switch_recursiveArrows_bool },
		recurs-arrows-cmd .tl_set:c  = { l__tensorstyles_tensor_#1_recursive_arrowCmd_tl },

		% bra-ket
		bra-ket .bool_set:c = { l__tensorstyles_tensor_#1_switch_dirac_bool },
		scale-var .choices:nn = { auto, none, big, Big, bigg, Bigg } { \__tensorstyles_set_scale:nnn {tensor_#1} {##1} { var } },
		scale-var .default:n = { auto },
		scale-var .initial:n = { auto },
		delims-var .tl_set:c  = { l__tensorstyles_tensor_#1_delims_var_tl },
		mix-delims .bool_set:c = { l__tensorstyles_tensor_#1_mix_delimiter_bool },

		% Einstein
		contra-variant .bool_set:c = { l__tensorstyles_tensor_#1_switch_einstein_bool },
		% \__tensorstyles_set_index_style:nnn #1= grp-cmd variant, #2= covariant or contra, #3= option selected,
		covariant-style .choices:nn = { alph, arabic, greek } { \__tensorstyles_set_index_style:nnn {#1} {covariant} {##1} },
		covariant-style .default:n = { greek },
		covariant-style .initial:n = { greek },
		contra-style .choices:nn = { alph, arabic, greek } { \__tensorstyles_set_index_style:nnn {#1} {contra} {##1} },
		contra-style .default:n = { alph },
		contra-style .initial:n = { alph },
		default-indices .choices:nn = { covariant, contra } { \__tensorstyles_set_index_type:nn {#1} { ##1 }},
		default-indices .default:n = { covariant },
		default-indices .initial:n = { covariant },
		index-marker .tl_set:c = { l__tensorstyles_tensor_#1_index_marker_tl },
		specific-indices .clist_set:c = { l__tensorstyles_tensor_#1_specific_indices_clist },
		collapsed-indices .bool_set:c = { l__tensorstyles_tensor_#1_collapsed_indices },
		index-offset .int_set:c = { l__tensorstyles_tensor_#1_index_offset },

		%%% Star Version
		%%%%%%%%%%%%%%%%

		% switch-** .bool_set:c = { l__tensorstyles_tensor_#1*_switch_star_bool },
		switch-** .code:n = { printSwitchStarStar },
		preset* .code:n   = {},
		deduce-var* .tl_set:c = { l__tensorstyles_tensor_#1*_deduce_var_tl },

		% font
		font* .bool_set:c = { l__tensorstyles_tensor_#1*_switch_font_bool },
		font-cmd* .code:n = { \prop_set_from_keyval:cn { l_tensorstyles_tensor_#1*_font_cmd_prop } {##1} },

		% arrow
		arrows* .bool_set:c = { l__tensorstyles_tensor_#1*_switch_arrows_bool },
		arrow-cmd* .code:n = { \prop_set_from_keyval:cn { l_tensorstyles_tensor_#1*_arrow_cmd_prop } {##1} },

		recursive-arrows* .bool_set:c = { l__tensorstyles_tensor_#1*_switch_recursiveArrows_bool },
		recurs-arrows-cmd* .tl_set:c  = { l__tensorstyles_tensor_#1*_recursive_arrowCmd_tl },

		% bra-ket
		bra-ket* .bool_set:c = { l__tensorstyles_tensor_#1*_switch_dirac_bool },
		scale-var* .choices:nn = { auto, none, big, Big, bigg, Bigg } { \__tensorstyles_set_scale:nnn {tensor_#1*} {##1} { var } },
		delims-var* .tl_set:c  = { l__tensorstyles_tensor_#1*_delims_var_tl },
		mix-delims* .bool_set:c = { l__tensorstyles_tensor_#1*_mix_delimiter_bool },

		% Einstein
		contra-variant* .bool_set:c = { l__tensorstyles_tensor_#1*_switch_einstein_bool },
		% \__tensorstyles_set_index_style:nnn #1= grp-cmd variant, #2= covariant or contra, #3= option selected,
		covariant-style* .choices:nn = { alph, arabic, greek } { \__tensorstyles_set_index_style:nnn {#1*} {covariant} {##1} },
		contra-style* .choices:nn = { alph, arabic, greek } { \__tensorstyles_set_index_style:nnn {#1*} {contra} {##1} },
		default-indices* .choices:nn = { covariant, contra } { \__tensorstyles_set_index_type:nn {#1*} { ##1 }},
		index-marker* .tl_set:c = { l__tensorstyles_tensor_#1*_index_marker_tl },
		specific-indices* .clist_set:c = { l__tensorstyles_tensor_#1*_specific_indices_clist },
		collapsed-indices* .bool_set:c = { l__tensorstyles_tensor_#1*_collapsed_indices },
		index-offset* .int_set:c = { l__tensorstyles_tensor_#1*_index_offset },
	}
}
%    \end{macrocode}
% 	\end{macro}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_tensor_define_preset_keys:n, \__tensorstyles_tensor_define_local_preset_keys:n}
% 		\begin{arguments}
% 			\item |variant| of the `tensor` group-command.
% 		\end{arguments}
% 		Define the keys and variables for presets.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\cs_new:Npn \__tensorstyles_tensor_define_preset_keys:n #1 {
	% Initialize variables to "empty" as baseline
	\tl_set:cn { l__tensorstyles_tensor_#1_preset  } { empty }
	\tl_set:cn { l__tensorstyles_tensor_#1*_preset } { empty }
	\keys_define:nn { tensorstyles/preset/#1 } {
		preset  .tl_set:c  = { l__tensorstyles_tensor_#1_preset  } ,
		preset* .tl_set:c  = { l__tensorstyles_tensor_#1*_preset } ,
		unknown .code:n    = {}
	}
}

\cs_new:Npn \__tensorstyles_tensor_define_local_preset_keys:n #1 {
	% Initialize variables to "empty" as baseline
	\tl_set:cn { l__tensorstyles_tensor_#1_local_preset  } { None }
	\tl_set:cn { l__tensorstyles_tensor_#1*_local_preset } { None }
	\keys_define:nn { tensorstyles/preset/#1 } {
		preset  .tl_set:c  = { l__tensorstyles_tensor_#1_local_preset  } ,
		preset* .tl_set:c  = { l__tensorstyles_tensor_#1*_local_preset } ,
		unknown .code:n    = {}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{variable}[added= 2025-02-17]{\c__tensorstyles_tensor_empty_pkg_keys_prop, \c__tensorstyles_tensor_einstein_pkg_keys_prop, \c__tensorstyles_tensor_math_pkg_keys_prop, \c__tensorstyles_tensor_arrow_pkg_keys_prop, \c__tensorstyles_tensor_engineer_pkg_keys_prop, \c__tensorstyles_tensor_bra_pkg_keys_prop, \c__tensorstyles_tensor_ket_pkg_keys_prop, \c__tensorstyles_tensor_full_pkg_keys_prop}
% 		Define dictionaries of presets.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-008}
%    \begin{macrocode}
\prop_const_from_keyval:Nn \c__tensorstyles_tensor_empty_pkg_keys_prop {
	% Font
	font = false,
	% Einstein index notation
	contra-variant = false,
	% Arrows
	arrows = false,
	recursive-arrows = false,
	% Dirac bra-ket
	bra-ket = false,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_einstein_pkg_keys_prop {
	% Font
	font = false,
	% Einstein index notation
	contra-variant = true,
	contra-style = alph,
	covariant-style = alph, %greek, %, alph, arabic
	default-indices = covariant,
	index-marker = \ ,
	collapsed-indices = false,
	specific-indices = {},
	index-offset = 0,
	% covariant-indices = 1,
	% indexOffset = 0,
	% Arrows
	arrows = false,
	recursive-arrows = false,
	% Dirac bra-ket
	% bra-ket = false,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_math_pkg_keys_prop {
	% Font
	font = true,
	font-cmd = {0={}, 1=\boldsymbol, 2=\MakeUppercase, 3=\MakeUpperCal, 4=\MakeUpperBB, 5=\MakeBoldUppercase, n=\mathfrak},
	% Einstein index notation
	contra-variant = false,
	% Arrows
	arrows = false,
	recursive-arrows = false,
	% Dirac bra-ket
	bra-ket = false,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_arrow_pkg_keys_prop {
	% Font
	font = false,
	% Einstein index notation
	contra-variant = false,
	% Arrows
	arrows = true,
	arrow-cmd = {0={}, 1=\overrightarrow, 2=\overleftrightarrow, 3=\overrightleftrightarrow, 4=\overdoubleleftrightarrow, 5=\overrightdoubleleftrightarrow, n=\underleftrightarrow},
	recursive-arrows = false,
	% Dirac bra-ket
	bra-ket = false,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_engineer_pkg_keys_prop {
	% Font
	font = false,
	% Einstein index notation
	contra-variant = false,
	% Arrows
	arrows = false,
	recursive-arrows = true,
	recurs-arrows-cmd =\underline,
	% Dirac bra-ket
	bra-ket = false,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_bra_pkg_keys_prop {
	% Font
	font = false,
	% Einstein index notation
	contra-variant = false,
	% Arrows
	arrows = false,
	recursive-arrows = false,
	% Dirac bra-ket
	bra-ket = true,
	scale-var = auto,
	delims-var = \langle\rvert,
	mix-delims = true,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_ket_pkg_keys_prop {
	% Font
	font = false,
	% Einstein index notation
	contra-variant = false,
	% Arrows
	arrows = false,
	recursive-arrows = false,
	% Dirac bra-ket
	bra-ket = true,
	scale-var = auto,
	delims-var = \lvert\rangle,
	mix-delims = true,
}

\prop_const_from_keyval:Nn \c__tensorstyles_tensor_full_pkg_keys_prop {
	% style-inf=d,
	% style-var = \bold,
	% switch-* = false,
	deduce-var= xX,
	% order = 1,
	% Font
	font = true,
	font-cmd = {0={}, 1=\boldsymbol, 2=\MakeUppercase, 3=\MakeUpperCal, 4=\MakeUpperBB, 5=\MakeBoldUppercase, n=\mathfrak}, %6=\mathfrak, n=\MakeUpperFrak},
	% Einstein index notation
	contra-variant = true,
	contra-style = alph,
	covariant-style = greek, %greek, %, alph, arabic
	default-indices = covariant,
	index-marker = \ ,
	collapsed-indices = false,
	specific-indices = {},
	index-offset = 0,
	% covariant-indices = 1,
	% indexOffset = 0,
	% Arrows
	arrows = true,
	arrow-cmd = {0={}, 1=\overrightarrow, 2=\overleftrightarrow, 3=\widetilde, 4=\overdoubleleftrightarrow, 5=\widehat, n=\underline},
	recursive-arrows = false,
	recurs-arrows-cmd = \underline,
	% Dirac bra-ket
	bra-ket = true,
	scale-var = auto,
	delims-var = \lbrace\rvert,
	mix-delims = true,
	% style= Dirac(bra-ket), Einstein-contravariant, engineer (underline), physics (double-curved-arrows), mathematics (bold)
}
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\tensorstyles_tensor_define:Nnn}
% 		\begin{arguments}
%  		\item |new/declare/renew/provide| corresponding to the type of command declaration desired.
%  		\item |variant| of the command group.
%  		\item |macro| for name (given by the user) the command that will be created.
% 		\end{arguments}
% 		Generic declaration of new function from tensor-type.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \tensorstyles_tensor_define:Nnn #1=new/declare/renew/provide,  #2=variant, #3=macro
\cs_new_protected:Npn \tensorstyles_tensor_define:Nnn #1 #2 #3 {
	% define the tensor-type of command: \declare {\toto}{ o m }{ code }
	\tl_new:c  { l__tensorstyles_tensor_#2_preset_default_tl }
	\exp_args:Nne #1 { #3 }{ s o m m o !e{\char_generate:nn {`_}{8}^} } {
	%% ##1: star, ##2: options, ##3: tensor order, ##4 variable, ##5: einstein indices, ##6: subscript, ##7: superscript
	\group_begin:
		% capture and treat eventual indices given
		\tl_if_in:cnTF { l__tensorstyles_tensor_#2_deduce_var_tl } {##3} {
			% \tl_show:c l__tensorstyles_tensor_#1_deduce_var_tl
			\tl_if_novalue:nTF {##5} { \int_set:Nn \l__tensorstyles_tensor_rank_counter_int 0} {
				\tl_set:Nn \l__tensorstyles_indices_tl {##5}
				\tl_map_inline:Nn \l__tensorstyles_indices_tl {
					\tl_if_single:nTF { ####1 } {
						\token_if_eq_meaning:NNTF ####1 ^{ }{
							\token_if_eq_charcode:NNTF ####1 _{ }{
								\int_incr:N \l__tensorstyles_tensor_rank_counter_int
							}
						}
					}
					{
						\int_incr:N \l__tensorstyles_tensor_rank_counter_int
					}
				}
			}
			\tl_set:Nn \l__tensorstyles_tensor_rank_holder_tl { \int_use:N \l__tensorstyles_tensor_rank_counter_int }
		}{
			\tl_set:Nn \l__tensorstyles_tensor_rank_holder_tl { ##3 }
		}

		% Capture and store presets.
		\tl_if_novalue:nTF { ##2 } {
			\tl_set:cn { l__tensorstyles_tensor_#2_preset_default_tl } { default }
		}{
			\use:c { __tensorstyles_tensor_define_local_preset_keys:n } { #2 }
			\keys_set:nn {tensorstyles/preset/#2} { ##2 }
			\tl_set:Nx \l_tmpa_tl { \tl_use:c { l__tensorstyles_tensor_#2_local_preset  } }

			\tl_set:Nx \l_tmpb_tl { \tl_use:c { l__tensorstyles_tensor_#2*_local_preset } }
			\tensorstyles_local_preset:nVVnn {#2} \l_tmpa_tl \l_tmpb_tl { tensor }
			\tl_set:cn { l__tensorstyles_tensor_#2_preset_default_tl } { pres }
		}

		%% \__tensorstyles_evaluation_sub_sup grp-cmd_variant, sub, sup, code-for-fraction
		\__tensorstyles_evaluation_sub_sup:nnnn {#2} {##6} {##7} {
			% if star is present
			\bool_if:nTF {##1} {
				% star only
				% Capture and apply options from keys.
				\tl_if_novalue:nTF { ##2 } {
					\tensorstyles_local_keys:nnnn { } { tensor } { #2 } { \tl_use:c {l__tensorstyles_tensor_#2_preset_default_tl} }
				}{
					\tensorstyles_local_keys:nnnn { ##2 } { tensor } { #2 } { \tl_use:c {l__tensorstyles_tensor_#2_preset_default_tl} * }
				}

				\__tensorstyles_tensor_no:nnen {#2*} {##4} {\tl_use:N \l__tensorstyles_tensor_rank_holder_tl} {##5}
			}{
				% treat a first time the option as if no star will be used (ie if switch-*=false)
				\tl_if_novalue:nTF { ##2 } {
					\tensorstyles_local_keys:nnnn { } { tensor } { #2 } { \tl_use:c {l__tensorstyles_tensor_#2_preset_default_tl} }
				}{
					\tensorstyles_local_keys:nnnn { ##2 } { tensor } { #2 } { \tl_use:c {l__tensorstyles_tensor_#2_preset_default_tl} }
				}

				\bool_if:cTF {l__tensorstyles_tensor_#2_switch_star_bool}{
					% star detected => retreat the options
					\tl_if_novalue:nTF { ##2 } {
						\tensorstyles_local_keys:nnnn { } { tensor } { #2 } { \tl_use:c {l__tensorstyles_tensor_#2_preset_default_tl} }
					}{
						\tensorstyles_local_keys:nnnn { ##2 } { tensor } { #2 } { \tl_use:c {l__tensorstyles_tensor_#2_preset_default_tl} * }
					}
					\__tensorstyles_tensor_no:nnen {#2*} {##4} {\tl_use:N \l__tensorstyles_tensor_rank_holder_tl} {##5}
				}{
					% no star
					\__tensorstyles_tensor_no:nnen {#2} {##4} {\tl_use:N \l__tensorstyles_tensor_rank_holder_tl} {##5}
				}
			}
		}
	\group_end:
	}
}
\cs_generate_variant:Nn \tensorstyles_tensor_define:Nnn { NV }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_tensor_no:nnnn}
% 		\begin{arguments}
%  		\item |grp-cmd(tensor)_variant| to which the setting is related to.
%  		\item |variable| to be displayed.
%  		\item |tensor order| (integer) of the variable.
%  		\item |indices| only if it has to be specified.
% 		\end{arguments}
% 		Command to display tensor command, ie apply font, then, arrows, index and delimiters.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \__tensorstyles_tensor_no:nnn #1= grp-cmd(tensor) variant, #2=variable, #3=tensor order, #4=Indices
\cs_new_protected:Npn \__tensorstyles_tensor_no:nnnn #1 #2 #3 #4 {
	\__tensorstyles_add_delims:nnn {#1} { var } {
		\__tensorstyles_add_einsteinIndex:nnnn {#1} {
			% \__tensorstyles_add_fontCmd:nnn #1= grp-cmd(tensor) variant, #2=variable, #3=tensor order
			\__tensorstyles_add_recursiveCmd:nnn {#1} {
				\__tensorstyles_add_arrowCmd:nnn {#1} {
					\__tensorstyles_add_fontCmd:nnn {#1} {#2} {#3}
				} {#3}
			} {#3}
		} {#3} {#4}
	}
}
\cs_generate_variant:Nn \__tensorstyles_tensor_no:nnnn { nnen }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


%
% %%%%%  Command Declaration  %%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \begin{implementation}
% 	\begin{variable}[added= 2025-02-17]{\l__tensorstyles_cs_name_tl}
% 		Local and temporary variable to concatenate the name of the command as a token list.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\tl_new:N \l__tensorstyles_cs_name_tl
\seq_new:N \g__tensorstyles_existing_command_seq
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{documentation}
% 	\begin{function}[added= 2025-02-17]{\DeclareTensorsCmd}
% 		\begin{arguments}
%  		\item |command name| to be declared.
%  		\item |keyval| (option) to be given to the new command as a first (non-default) setup.
% 		\end{arguments}
% 		Command to declare a new command from a command group, with eventually options to be given to this new option.
% 		Such new definition are useful for users who would like to create their own custom command that will have the same behaviour than the ones furnished by the package.
% 	\end{function}
% \end{documentation}
%%%%
% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\DeclareTensorsCmd}
% 		\begin{arguments}
%  		\item |command name| to be defined/declared.
%  		\item |keyval| (option) to be given to the new command as a first (non-default) setup.
% 		\end{arguments}
% 		Command accessible by the users to declare a new command from a command group, with eventually options to be given to this new option.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\DeclareDocumentCommand{\DeclareTensorsCmd}{ m o } {
	% \tensorstyles_addto_globalvar_and_setkeys:NNnnnnnn tl-tensor, macro, inf, keyval, preset, star-keyval, star-preset group command
	\tensorstyles_addto_globalvar_and_setkeys:NNnnn \l__tensorstyles_cs_name_tl #1 {d} { #2 } { tensor }

	% \tensorstyles_tensor_define:NVn  declare/renew..., variant, macro
	% DeclareDocumentCommand #1 { #2 } { #3 }
	\tensorstyles_tensor_define:NVn \DeclareDocumentCommand \l__tensorstyles_cs_name_tl { #1 }

	\seq_put_right:Nn \g__tensorstyles_existing_command_seq { #1 }
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

%
% %%%%%  Rest of the Code (common)  %%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_set_scale:nnn}
% 		\begin{arguments}
%  		\item |grp-cmd_variant| for which the scaling will be set.
%  		\item |scale| the desired scale, eg, auto or none or big or Big...
%  		\item |delimiters-name| the name of the category of delimiters to scale.
% 		\end{arguments}
% 		Set the scale of a pair of delimiters.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \__tensorstyles_set_scale:nnn #1=grp-cmd_variant, #2=scale, #3=delimiter-name
\cs_new:Npn \__tensorstyles_set_scale:nnn #1 #2 #3 {
	\str_case:nnF { #2 }{
		% if the scale desired is 'auto' or 'none'
		{ auto } { \tl_set:cn { l__tensorstyles_#1_scale_#3_tl } { \__tensorstyles_scale_auto:nnn } }
		{ none } { \tl_set:cn { l__tensorstyles_#1_scale_#3_tl } { \__tensorstyles_scale_none:nnn } }
	}{
		% otherwise, applied the given scale
		\tl_set:cn { l__tensorstyles_#1_scale_#3_tl } { \__tensorstyles_scale_big:nnnn { #2 } }
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


%
% %%%%%  Scale, delimiters, evaluation  %%%%%
%
%
% \begin{implementation}
% 	\begin{variable}[added= 2025-02-12, updated= 2025-02-12]{\g__tensorstyles_last_delim, \g__tensorstyles_follow_up}
% 		|\g__tensorstyles_follow_up| is capturing if the delimiters are followed by another, in order to maybe compress them.
% 		|\g__tensorstyles_last_delim| is capturing the last delimiter seen.
% 		\changes{v1.0.1}{2025-02-12}{original version}
%    \begin{macrocode}
% counters and local variables
\bool_new:N \g__tensorstyles_follow_up
\tl_new:N \g__tensorstyles_last_delim
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_add_delims:nnn}
% 		\begin{arguments}
%  		\item |grp-cmd_variant| for which the scaling will be set.
%  		\item |delimiters-name| name of the delimiters to add.
%  		\item |inner-arg| inside value between the delimiters.
% 		\end{arguments}
% 		Apply a pair of delimiters (scaled) around an inner argument.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \__tensorstyles_add_delims:nnn #1=grp-cmd_variant, #2=delimiter-name, #3=value
\cs_new:Npn \__tensorstyles_add_delims:nnn #1 #2 #3 {
	\bool_if:cTF {l__tensorstyles_tensor_#1_switch_dirac_bool} {
		\tl_use:c { l__tensorstyles_tensor_#1_scale_#2_tl } { tensor_#1 } { #2 } { #3 }
		\tl_set:Nx \l_tmpb_tl { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 2 } }
		\bool_if:cTF {l__tensorstyles_tensor_#1_mix_delimiter_bool} {
			\seq_map_inline:Nn \g__tensorstyles_existing_command_seq {
				\bool_gset_false:N \g__tensorstyles_follow_up
				\token_if_eq_meaning:NNT \l_peek_token ##1 {
					\bool_gset_true:N \g__tensorstyles_follow_up
					\tl_gset:Nx \g__tensorstyles_last_delim { \tl_item:cn { l__tensorstyles_tensor_#1_delims_#2_tl } { 2 } }
					\seq_map_break:
				}
			}
		} {
			\bool_gset_false:N \g__tensorstyles_follow_up
		}
	}{
		#3
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_scale_auto:nnn}
% 		\begin{arguments}
%  		\item |grp-cmd_variant| for which the scaling will be set.
%  		\item |delimiters-name| name of the delimiters to add.
%  		\item |inner-code| inside value to be displayed between the delimiters.
% 		\end{arguments}
% 		Command for auto scaling delimiters (mleft and mright).
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%\__tensorstyles_scale_auto:nnn #1=grp-cmd_variant, #2=delimiters-name, #3=inner-arg
\cs_new:Npn \__tensorstyles_scale_auto:nnn #1 #2 #3 {
	\tl_set:Nx \l_tmpa_tl { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 1 } }
	\tl_set:Nx \l_tmpb_tl { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 2 } }
	\tl_if_empty:NTF \l_tmpa_tl { } {
		\bool_if:NTF \g__tensorstyles_follow_up {
			\bool_if:cTF {l__tensorstyles_#1_mix_delimiter_bool} {
				\tl_if_eq:NNTF \g__tensorstyles_last_delim \l_tmpa_tl {
					\! \__tensorstyles_auto_left:n .
				} {
					\tl_if_eq:NnTF \g__tensorstyles_last_delim { \rvert } {
						\tl_if_eq:NnTF \l_tmpa_tl { \lvert } {
							\! \__tensorstyles_auto_left:n .
						} {
							\__tensorstyles_auto_left:n \l_tmpa_tl
						}
					} {
						\__tensorstyles_auto_left:n \l_tmpa_tl
					}
				}
			}{
				\__tensorstyles_auto_left:n \l_tmpa_tl
			}
		} {
			\__tensorstyles_auto_left:n \l_tmpa_tl
		}
	}
	#3
	\tl_if_empty:NTF \l_tmpb_tl { } {
		\__tensorstyles_auto_right:n \l_tmpb_tl
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_scale_none:nnn}
% 		\begin{arguments}
%  		\item |grp-cmd_variant| for which the scaling will be set.
%  		\item |delimiters-name| name of the delimiters to add.
%  		\item |inner-code| inside value to be displayed between the delimiters.
% 		\end{arguments}
% 		Command for intentionally no-scaling delimiters.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%\__tensorstyles_scale_none:nnn #1=grp-cmd_variant, #2=delimiters-name, #3=inner-arg
\cs_new:Npn \__tensorstyles_scale_none:nnn #1 #2 #3 {
	\tl_set:Nx \l_tmpa_tl { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 1 } }
	\tl_set:Nx \l_tmpb_tl { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 2 } }
	\tl_if_empty:NTF \l_tmpa_tl { } {
		\bool_if:NTF \g__tensorstyles_follow_up {
			\bool_if:cTF {l__tensorstyles_#1_mix_delimiter_bool} {
				\tl_if_eq:NNTF \g__tensorstyles_last_delim \l_tmpa_tl { } {
					\tl_if_eq:NnTF \g__tensorstyles_last_delim { \rvert } {
						\tl_if_eq:NnTF \l_tmpa_tl { \lvert } { } {
							\__tensorstyles_dont_use_dot:x { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 1 } }
						}
					} {
						\__tensorstyles_dont_use_dot:x { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 1 } }
					}
				}
			} {
				\__tensorstyles_dont_use_dot:x { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 1 } }
			}
		} {
			\__tensorstyles_dont_use_dot:x { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 1 } }
		}
	}
	#3
	\__tensorstyles_dont_use_dot:x { \tl_item:cn { l__tensorstyles_#1_delims_#2_tl } { 2 } }
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_dont_use_dot:n}
% 		\begin{arguments}
%  		\item |delimiter-symbol| to be not scaled.
% 		\end{arguments}
% 		Command to force no scaling on the given delimiter.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \__tensorstyles_dont_use_dot:n #1=delimiter-symbol
\cs_new:Npn \__tensorstyles_dont_use_dot:n #1 {
	\str_if_eq:nnF { #1 } { . } { #1 }
}
\cs_generate_variant:Nn \__tensorstyles_dont_use_dot:n { x }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_scale_big:nnnn, \__tensorstyles_scale_big_auxi:nNn}
% 		\begin{arguments}
%  		\item |scale| the desired scale, eg, big or Big...
%  		\item |grp-cmd_variant| for which the scaling will be set.
%  		\item |delimiters-name| the name of the category of delimiters to scale.
%  		\item |inner-code| inside value to be displayed between the delimiters.
% 		\end{arguments}
% 		Apply the scale of a pair of delimiters and display what is inside.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%\__tensorstyles_scale_big:nnnn #1 #2=grp-cmd_variant, #3=delimiters-name, #4=inner-code
\cs_new:Npn \__tensorstyles_scale_big:nnnn #1 #2 #3 #4 {
	\__tensorstyles_scale_big_auxi:ncnn { #1 } {l__tensorstyles_#2_delims_#3_tl} { #4 } { #2 }
}
%
% \__tensorstyles_scale_big_auxi:nNn #1=scaling, #2=delimiters, #3=inner-code, #4=grp-cmd
\cs_new:Npn \__tensorstyles_scale_big_auxi:nNnn #1 #2 #3 #4 {
	\tl_set:Nx \l_tmpa_tl { \tl_item:Nn #2 { 1 } }
	\tl_set:Nx \l_tmpb_tl { \tl_item:Nn #2 { 2 } }
	\tl_if_empty:NTF \l_tmpa_tl { } {
		\bool_if:NTF \g__tensorstyles_follow_up {
			\bool_if:cTF {l__tensorstyles_#4_mix_delimiter_bool} {
				\tl_if_eq:NNTF \g__tensorstyles_last_delim \l_tmpa_tl { } {
					\tl_if_eq:NnTF \g__tensorstyles_last_delim { \rvert } {
						\tl_if_eq:NnTF \l_tmpa_tl { \lvert } { } {
							\tl_use:c { #1 l } { \tl_item:Nn #2 { 1 } }
						}
					}{
						\tl_use:c { #1 l } { \tl_item:Nn #2 { 1 } }
					}
				}
			}{
				\tl_use:c { #1 l } { \tl_item:Nn #2 { 1 } }
			}
		}{
			\tl_use:c { #1 l } { \tl_item:Nn #2 { 1 } }
		}
	}
	#3
	\tl_use:c { #1 r } { \tl_item:Nn #2 { 2 } }
}
\cs_generate_variant:Nn \__tensorstyles_scale_big_auxi:nNnn { nc }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\nam\__tensorstyles_evaluation_sub_sup:nnnn}
% 		\begin{arguments}
% 			\item |variant| Name of the variant grp-cmd
% 			\item |sub| subscript to add to the inner code
% 			\item |sup| superscript to add to the inner code
% 			\item |inner code| on which the sub and sup will be added
% 		\end{arguments}
% 		Function to add sub and superscript to an inner variable.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%
% \__tensorstyles_evaluation_sub_sup:nnnn #1=variant #2=sub #3=sup #4=inner part
\cs_new:Npn \__tensorstyles_evaluation_sub_sup:nnnn #1 #2 #3 #4 {
	\tl_if_novalue:nTF {#2} {
		% if no value, skip sub-point
		\tl_if_novalue:nTF {#3}	{
			% if no value skip sup-point, then add only the code-fraction
			#4
		}{
			% if value add only sup-point
			{#4}
			\sp{ #3 }
		}
	}{
		% if value, add sub-point
		{#4}
		\sb{ #2 }
		\tl_if_novalue:nTF {#3}	{
			% if no value skip sup-point
		}{
			\sp{ #3 }
		}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


% \begin{implementation}
% 	\begin{variable}[added= 2025-02-12, updated= 2025-02-12]{\l__indice_sub_bool}
% 		|\l__indice_sub_bool| is triggering either indices should be displayed
% 		\changes{v1.0.1}{2025-02-12}{original version}
%    \begin{macrocode}
% counters and local variables
\bool_new:N \l__indice_sub_bool
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{variable}[added= 2025-02-12, updated= 2025-02-12]{\l__tensorstyles_var_int_tmpa, \g__tensorstyles_offset_int_tmpa}
% 		|\l__tensorstyles_var_int_tmpa| is internal index counter
% 		|\g__tensorstyles_offset_int_tmpa| is the offset to apply on the index counter.
% 		\changes{v1.0.1}{2025-02-12}{original version}
%    \begin{macrocode}
% counters and local variables
\int_new:N \l__tensorstyles_var_int_tmpa
\int_new:N \g__tensorstyles_offset_int_tmpa
\int_gset:Nn \g__tensorstyles_offset_int_tmpa {0}
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{variable}[added= 2025-02-12, updated= 2025-02-12]{\l__tensorstyles_covariant_seq_tmpa, \l__tensorstyles_covariant_manual_seq_tmpa, \l__tensorstyles_contra_seq_tmpa, \l__tensorstyles_contra_manual_seq_tmpa, \l__tensorstyles_indices_tl, \l_tmp_covariant_tl, \l_tmp_contra_tl, \l_tmpc_dim}
% 		|\l__tensorstyles_covariant_seq_tmpa| is local sequence of covariant index
% 		|\l__tensorstyles_covariant_manual_seq_tmpa| is the local sequence of covariant index given manually
% 		|\l__tensorstyles_contra_seq_tmpa| is the local sequence of contravariant of index
% 		|\l__tensorstyles_contra_manual_seq_tmpa| is the local sequence of contravariant of index given manually
% 		|\l__tensorstyles_indices_tl| is the token list that will be decoded to create the sequence
% 		|\l_tmp_covariant_tl|
% 		|\l_tmp_contra_tl|
% 		|\l_tmpc_dim| the internal length for collapsed indices
% 		\changes{v1.0.1}{2025-02-12}{original version}
%    \begin{macrocode}
% counters and local variables
\seq_new:N \l__tensorstyles_covariant_seq_tmpa
\seq_new:N \l__tensorstyles_covariant_manual_seq_tmpa
\seq_new:N \l__tensorstyles_contra_seq_tmpa
\seq_new:N \l__tensorstyles_contra_manual_seq_tmpa

\tl_new:N \l__tensorstyles_indices_tl
\tl_new:N \l_tmp_covariant_tl
\tl_new:N \l_tmp_contra_tl

\dim_new:N \l_tmpc_dim
%    \end{macrocode}
% 	\end{variable}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_manual_indices:nn}
% 		\begin{arguments}
% 			\item |grp-cmd(tensor) variant| variant of the tensor grp-cmd that is used.
% 			\item |index list| to add manually
% 		\end{arguments}
% 		Adds indices manually (since they have been given by the user) without collapse of indices.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-006}
%    \begin{macrocode}

%\__tensorstyles_add_manual_indices:nn #1= grp-cmd(tensor) variant, #2 = index list
\cs_new_protected:Npn \__tensorstyles_add_manual_indices:nn #1 #2 {
	\tl_set:Nn \l__tensorstyles_indices_tl {#2}
	% browse the list
	\tl_map_inline:Nn \l__tensorstyles_indices_tl
	{
		\tl_if_single:nTF { ##1 } {
			\token_if_eq_meaning:NNTF ##1 ^{
				\bool_set_false:N \l__indice_sub_bool
			}{
				\token_if_eq_charcode:NNTF ##1 _{
					\bool_set_true:N \l__indice_sub_bool
				}{
					\settowidth{\l_tmpa_dim}{$##1$}
					\bool_if:NTF \l__indice_sub_bool{
						\seq_put_right:Nx \l__tensorstyles_covariant_seq_tmpa {
							\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
							{ ##1 }
						}
						\seq_put_right:Nx \l__tensorstyles_contra_seq_tmpa {
							\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
							{ \exp_not:v { l__tensorstyles_tensor_#1_index_marker_tl } }
						}
					}{
						\seq_put_right:Nx \l__tensorstyles_contra_seq_tmpa {
							\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
							{ ##1 }
						}
						\seq_put_right:Nx \l__tensorstyles_covariant_seq_tmpa {
							\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
							{ \exp_not:v { l__tensorstyles_tensor_#1_index_marker_tl } }
						}
					}
					\int_incr:N \l__tensorstyles_var_int_tmpa
				}
			}
		}{
			%Index is a group
			\settowidth{\l_tmpa_dim}{$##1$}
			\bool_if:NTF \l__indice_sub_bool{
				\seq_put_right:Nx \l__tensorstyles_covariant_seq_tmpa {
					\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
					{ \exp_not:n {##1} }
				}
				\seq_put_right:Nx \l__tensorstyles_contra_seq_tmpa {
					\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
					\exp_not:v { l__tensorstyles_tensor_#1_index_marker_tl }
				}
			}{
				\seq_put_right:Nx \l__tensorstyles_contra_seq_tmpa {
					\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
					{ \exp_not:n {##1} }
				}
				\seq_put_right:Nx \l__tensorstyles_covariant_seq_tmpa {
					\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpa_dim \exp_not:n {][c]}
					\exp_not:v { l__tensorstyles_tensor_#1_index_marker_tl }
				}
			}
			\int_incr:N \l__tensorstyles_var_int_tmpa
		}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_manual_collapsed_indices:n}
% 		\begin{arguments}
% 			\item |index list| to add manually
% 		\end{arguments}
% 		Adds indices manually (since they have been given by the user) with collapse of indices.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-006}
%    \begin{macrocode}

%\__tensorstyles_add_manual_collapsed_indices:n #1= index list
\cs_new_protected:Npn \__tensorstyles_add_manual_collapsed_indices:n #1 {
	\tl_set:Nn \l__tensorstyles_indices_tl {#1}
	\tl_map_inline:Nn \l__tensorstyles_indices_tl
	{
		\tl_if_single:nTF { ##1 } {
			\token_if_eq_meaning:NNTF ##1 ^{
				\bool_set_false:N \l__indice_sub_bool
			}{
				\token_if_eq_charcode:NNTF ##1 _{
					\bool_set_true:N \l__indice_sub_bool
				}{
					\bool_if:NTF \l__indice_sub_bool{
						\seq_put_right:Nx \l__tensorstyles_covariant_manual_seq_tmpa { ##1 }
					}{
						\seq_put_right:Nx \l__tensorstyles_contra_manual_seq_tmpa { ##1 }
					}
					\int_incr:N \l__tensorstyles_var_int_tmpa
				}
			}
		}{
			\bool_if:NTF \l__indice_sub_bool{
				\seq_put_right:Nx \l__tensorstyles_covariant_manual_seq_tmpa { ##1 }
			}{
				\seq_put_right:Nx \l__tensorstyles_contra_manual_seq_tmpa { ##1 }
			}
			\int_incr:N \l__tensorstyles_var_int_tmpa
		}
	}
	\int_step_inline:nn {
		\int_max:nn { \seq_count:N \l__tensorstyles_covariant_manual_seq_tmpa } { \seq_count:N \l__tensorstyles_contra_manual_seq_tmpa }
	}{
		\tl_set:Nx \l_tmp_covariant_tl { \seq_item:Nn \l__tensorstyles_covariant_manual_seq_tmpa { ##1 } }
		\tl_set:Nx \l_tmp_contra_tl { \seq_item:Nn \l__tensorstyles_contra_manual_seq_tmpa { ##1 } }
		\settowidth{\l_tmpa_dim}{$\l_tmp_covariant_tl$}
		\settowidth{\l_tmpb_dim}{$\l_tmp_contra_tl$}
		\dim_compare:nTF { \l_tmpa_dim > \l_tmpb_dim }{
			\dim_set_eq:NN \l_tmpc_dim \l_tmpa_dim
		}{
			\dim_set_eq:NN \l_tmpc_dim \l_tmpb_dim
		}

		\seq_put_right:Nx \l__tensorstyles_covariant_seq_tmpa {
			\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpc_dim \exp_not:n {][c]}
			{ \exp_not:V \l_tmp_covariant_tl }
		}

		\seq_put_right:Nx \l__tensorstyles_contra_seq_tmpa {
			\exp_not:n { \mathmakebox[} \dim_use:N \l_tmpc_dim \exp_not:n {][c]}
			{ \exp_not:V \l_tmp_contra_tl }
		}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_one_einsteinIndex:nnn}
% 		\begin{arguments}
% 			\item |grp-cmd(tensor) variant| variant of the tensor grp-cmd that is used.
% 			\item |index-style| ie alph, greek or arabic
% 			\item |index-type| ie contra or covariant
% 		\end{arguments}
% 		Adds only one Einstein index.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-006}
%    \begin{macrocode}
% \usepackage{mathtools} % for \mathmakebox

% \__tensorstyles_add_one_einsteinIndex:nn #1= grp-cmd(tensor) variant, #2=Indice type #3=Blank Type
\cs_new_protected:Npn \__tensorstyles_add_one_einsteinIndex:nnn #1 #2 #3 {
	\settowidth{\l_tmpa_dim}{$\use:c { l__tensorstyles_tensor_#1_indexstyle_#2_tl }{\int_eval:n{\l__tensorstyles_var_int_tmpa+\g__tensorstyles_offset_int_tmpa}}$}
	\seq_put_right:cx { l__tensorstyles_#2_seq_tmpa } {
		\exp_not:n { \mathmakebox[\l_tmpa_dim][c] }
		{ \exp_not:c { l__tensorstyles_tensor_#1_indexstyle_#2_tl }
		{ \int_use:N \l__tensorstyles_var_int_tmpa }
		}
	}

	\bool_if:cTF {l__tensorstyles_tensor_#1_collapsed_indices} {
		% We do not add any marker
	}{
		\seq_put_right:cx { l__tensorstyles_#3_seq_tmpa } {
			\exp_not:n { \mathmakebox[\l_tmpa_dim][c] }
			{ \exp_not:v { l__tensorstyles_tensor_#1_index_marker_tl } }
		}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_einsteinIndex:nnnn}
% 		\begin{arguments}
% 			\item |grp-cmd(tensor) variant| variant of the tensor grp-cmd that is used.
% 			\item |variable| variable on which the indices will be added
% 			\item |tensor order| to determine the number of indices to add.
% 			\item |indices| if the list has been explicitly defined by the user.
% 		\end{arguments}
% 		Adds multiple Einstein indices
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-006}
%    \begin{macrocode}

% \__tensorstyles_add_einsteinIndex:nnnn #1= grp-cmd(tensor) variant, #2=variable, #3=tensor order #4=Indices
\cs_new_protected:Npn \__tensorstyles_add_einsteinIndex:nnnn #1 #2 #3 #4 {
	\bool_if:cTF {l__tensorstyles_tensor_#1_switch_einstein_bool} {
		% true switch einstein
		\seq_clear:N \l__tensorstyles_covariant_seq_tmpa
		\seq_clear:N \l__tensorstyles_contra_seq_tmpa
		% Do we raise an error if we do not add #3 indices?
		\tl_if_novalue:nTF {#4} {
			\tl_if_in:NnTF \c__tensorstyles_digits_tl {#3} {
				% The order is a number
				\int_set:Nn \l__tensorstyles_var_int_tmpa { \int_use:c { l__tensorstyles_tensor_#1_index_offset } }
				\int_step_inline:nn {#3} {
					% increase the counter
					\int_incr:N \l__tensorstyles_var_int_tmpa

					\tl_set:Nx \l_tmpa_tl { \int_eval:n { \l__tensorstyles_var_int_tmpa - \int_use:c { l__tensorstyles_tensor_#1_index_offset } } }
					\clist_if_in:cVTF { l__tensorstyles_tensor_#1_specific_indices_clist } \l_tmpa_tl
					{
						\exp_args:Nne \__tensorstyles_add_one_einsteinIndex:nnn {#1} { \tl_use:c { l__tensorstyles_tensor_#1_opposed_indices_tl }} { \tl_use:c { l__tensorstyles_tensor_#1_default_indices_tl } }
					}
					{
						\exp_args:Nne \__tensorstyles_add_one_einsteinIndex:nnn {#1} { \tl_use:c { l__tensorstyles_tensor_#1_default_indices_tl }} { \tl_use:c { l__tensorstyles_tensor_#1_opposed_indices_tl } }
					}
					% add this counter (+ the offset) of the sequence of index
				}
			}{
				% if the order is not a number then add it as if it a vector.
				\seq_put_right:Nx \l__tensorstyles_covariant_seq_tmpa {
					\__tensorstyles_add_fontCmd:nnn {#1} {#3} {1}
				}
			}
		}{
			%Indices were given manually
			\bool_if:cTF {l__tensorstyles_tensor_#1_collapsed_indices} {
				\__tensorstyles_add_manual_collapsed_indices:n {#4}
			}{
				\__tensorstyles_add_manual_indices:nn {#1} {#4}
			}
			\int_compare:nTF { \l__tensorstyles_var_int_tmpa = #3 } {
				%Rank and number of indices match
			}{
				%User has given too many or not enough indices
				\msg_error:nnx { tensorstyles } { rank_indices_missmatch } { \msg_line_context: }
			}
		}
		% print
		#2\sb{
			\seq_use:Nn \l__tensorstyles_covariant_seq_tmpa {}
		}\sp{
			\seq_use:Nn \l__tensorstyles_contra_seq_tmpa {}
		}
	}{
		% false switch font
		#2
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_set_index_style:nnn}
% 		\begin{arguments}
% 			\item |grp-cmd(tensor) variant| variant of the tensor grp-cmd that is used.
% 			\item |index-type| covariant or contra.
% 			\item |index-style| greek, alph or arabic.
% 		\end{arguments}
% 		Turn the index integer into a string according to the index-style to use.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-006}
%    \begin{macrocode}

% \__tensorstyles_set_index_style:nnn #1= grp-cmd variant, #2= index-type, #3= index-style,
\cs_new:Npn \__tensorstyles_set_index_style:nnn #1 #2 #3 {
	\str_case:nnF {#3} {
		{ alph  }{ \tl_set:cn { l__tensorstyles_tensor_#1_indexstyle_#2_tl } { \int_to_alph:n } }
		{ arabic }{ \tl_set:cn { l__tensorstyles_tensor_#1_indexstyle_#2_tl } { \int_to_arabic:n } }
		{ greek  }{ \tl_set:cn { l__tensorstyles_tensor_#1_indexstyle_#2_tl } { \int_to_greek:n } }
	}{
		\msg_error:nnxx { tensorstyles } { index-style-option-not-defined }
		{#3} {'#3'}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_set_index_style:nnn}
% 		\begin{arguments}
% 			\item |grp-cmd(tensor) variant| variant of the tensor grp-cmd that is used.
% 			\item |index-type| covariant or contra.
% 		\end{arguments}
% 		Set the default index type to use.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-006}
%    \begin{macrocode}

% \__tensorstyles_set_index_type:nnn #1= grp-cmd variant, #2= index-type
\cs_new:Npn \__tensorstyles_set_index_type:nn #1 #2 {
	\tl_set:cn { l__tensorstyles_tensor_#1_default_indices_tl } { #2 }
	\str_case:nnF {#2} {
		{ covariant }{
			\tl_set:cn { l__tensorstyles_tensor_#1_default_indices_tl } { covariant }
			\tl_set:cn { l__tensorstyles_tensor_#1_opposed_indices_tl } { contra }
		}{ contra }{
			\tl_set:cn { l__tensorstyles_tensor_#1_default_indices_tl } { contra }
			\tl_set:cn { l__tensorstyles_tensor_#1_opposed_indices_tl } { covariant }
		}
	}{
		\msg_error:nnxx { tensorstyles } { index-type-option-not-defined }
		{#2} {'#2'}
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_fontCmd:nnn}
% 		\begin{arguments}
% 			\item |variant| grp-cmd(tensor) variant
% 			\item |variable| on which the font command will be applied
% 			\item |tensor order| to determine which font select.
% 		\end{arguments}
% 		Apply a font on a variable according to the tensor order.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}

% \__tensorstyles_add_fontCmd:nnn #1= grp-cmd(tensor) variant, #2=variable, #3=tensor order
\cs_new_protected:Npn \__tensorstyles_add_fontCmd:nnn #1 #2 #3 {
	\bool_if:cTF {l__tensorstyles_tensor_#1_switch_font_bool}{
		% true switch font
		\prop_if_in:cnTF {l_tensorstyles_tensor_#1_font_cmd_prop} {#3} {
			% true
			%\exp_args:NNV
			\prop_item:cn {l_tensorstyles_tensor_#1_font_cmd_prop} {#3} {#2}
		}{
			% false
			false\ the\ order\ #3\ is\ not\ present\ in\ font\ option!
		}
	}{
		% false switch font
		#2
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}


% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\int_to_greek:n}
% 		\begin{arguments}
% 			\item |integer| to turn into a symbol (string).
% 		\end{arguments}
% 		Function that returns the greek symbol corresponding to the integer given.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%%
\cs_new:Npn \int_to_greek:n #1 {
	% \int_to_symbols:nnn {⟨int expr ⟩} {⟨total symbols ⟩} {⟨value to symbol mapping ⟩}
	\int_to_symbols:nnn {#1} { 23 } {
		{ 1  }{ \alpha }
		{ 2  }{ \beta }
		{ 3  }{ \gamma }
		{ 4  }{ \delta }
		{ 5  }{ \varepsilon }
		{ 6  }{ \zeta }
		{ 7  }{ \eta }
		{ 8  }{ \theta }
		{ 9  }{ \iota }
		{ 10 }{ \kappa }
		{ 11 }{ \lambda }
		{ 12 }{ \mu }
		{ 13 }{ \nu }
		{ 14 }{ \xi }
		{ 15 }{  o }
		{ 16 }{ \pi }
		{ 17 }{ \varrho }
		{ 18 }{ \sigma }
		{ 19 }{ \tau }
		{ 20 }{ \upsilon }
		{ 21 }{ \phi }
		{ 22 }{ \chi }
		{ 23 }{ \psi }
		{ 23 }{ \omega }
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\recursive_cmd:nnn}
% 		\begin{arguments}
% 			\item |cmd| to apply recursively
% 			\item |number| of occurrence to apply
% 			\item |variable| on which the recursively command will be applied
% 		\end{arguments}
% 		Apply a given number of times a command on an input variable.
% 		The input command (to apply) can only take one positional argument.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}

% internal variable to store the counter of occurrence
\int_new:N \g__tensorstyles_int_tmpa
%
% \recursive_cmd:nnn cmd, number, var
\cs_set:Npn \recursive_cmd:nnn #1 #2 #3 {
	\group_begin:
		%
		% all variable assignments will be constrained in this group
		\int_gset:Nn \g__tensorstyles_int_tmpa {#2}
		%
		% while the number of call is higher than 1
		\int_compare:nNnTF {#2} > {1} {
			%true	% then apply recursively the command
			\int_gdecr:N \g__tensorstyles_int_tmpa
			\exp_args:Nnx \recursive_cmd:nnV {#1} {\int_use:N \g__tensorstyles_int_tmpa} {#1{#3}}
		}{
			% false %
			\int_compare:nNnTF {#2} = {0} {
				%true
				#3
			}{
				% false % equal 1
				#1{#3}
			}
		}
	\group_end:
}
% variant command for \recursive_cmd:nnn
\cs_generate_variant:Nn \recursive_cmd:nnn { nnV, vnn }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_recursiveCmd:nnn}
% 		\begin{arguments}
% 			\item |variant| grp-cmd(tensor) variant
% 			\item |variable| on which the recursively command will be applied
% 			\item |tensor order| which will correspond to the number of occurrence to apply recursively
% 		\end{arguments}
% 		Apply (if needed) as many time as the tensor order a command on an input variable.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%
% \__tensorstyles_add_recurseCmd:nnn #1= grp-cmd(tensor) variant, #2=variable, #3=tensor order
\cs_new_protected:Npn \__tensorstyles_add_recursiveCmd:nnn #1 #2 #3 {
	\bool_if:cTF {l__tensorstyles_tensor_#1_switch_recursiveArrows_bool} {
		% true switch recursive
		\tl_if_in:NnTF \c__tensorstyles_digits_tl {#3} {
			% The order is a number
			\recursive_cmd:vnn {l__tensorstyles_tensor_#1_recursive_arrowCmd_tl} {#3} {#2}
		}{
			% else the order is a letter
			\__tensorstyles_add_arrowCmd:nnn {#1} {#2} {#3}
		}
	}{
		% false switch recursive
		#2
	}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\__tensorstyles_add_arrowCmd:nnn}
% 		\begin{arguments}
% 			\item |variant| grp-cmd(tensor) variant
% 			\item |variable| on which the arrow command will be applied
% 			\item |tensor order| to determine which arrow command apply
% 		\end{arguments}
% 		Apply an arrow-command according to the tensor-order on an input variable.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}

% \__tensorstyles_add_arrowCmd:nnn #1= grp-cmd(tensor) variant, #2=variable, #3=tensor order
\cs_new_protected:Npn \__tensorstyles_add_arrowCmd:nnn #1 #2 #3 {
	\bool_if:cTF {l__tensorstyles_tensor_#1_switch_arrows_bool} {
		% true switch arrow
		\prop_if_in:cnTF {l_tensorstyles_tensor_#1_arrow_cmd_prop} {#3} {
			% true
			\prop_item:cn {l_tensorstyles_tensor_#1_arrow_cmd_prop} {#3} {#2}
		}{
			% false
			false\ the\ order\ #3\ is\ not\ present\ in\ arrows\ option!
			\prop_show:c {l_tensorstyles_tensor_#1_arrow_cmd_prop}
		}
	}{
		% false switch arrow
		#2
	}
}

%    \end{macrocode}
% 	\end{function}
% \end{implementation}

% \begin{documentation}
% 	\begin{function}{\MakeBoldUppercase, \MakeUpperBB, \MakeUpperCal, \MakeUpperFrak, \overdoubleleftrightarrow, \overrightleftrightarrow, \overrightdoubleleftrightarrow}
%  	\begin{syntax}
% 			\cs{MakeBoldUppercase, MakeUpperBB, MakeUpperCal, MakeUpperFrak, overdoubleleftrightarrow, overrightleftrightarrow, overrightdoubleleftrightarrow}\marg{variable}
% 		\end{syntax}
% 		Commands applying a combination of font commands or glyph (arrow) commands.
% 		The combinations are quite explicit from the command names.
% 	\end{function}
% \end{documentation}
%%%%
% \begin{implementation}
% 	\begin{function}[added= 2025-02-12, updated= 2025-02-12]{\MakeBoldUppercase, \MakeUpperBB, \MakeUpperCal, \MakeUpperFrak, \overdoubleleftrightarrow, \overrightleftrightarrow, \overrightdoubleleftrightarrow}
% 		\begin{arguments}
% 			\item |cmd| to apply recursively
% 			\item |number| of occurrence to apply
% 			\item |variable| on which the recursively command will be applied
% 		\end{arguments}
% 		Apply a given number of times a command on an input variable.
% 		The input command (to apply) can only take one positional argument.
% 		\changes{v1.0.1}{2025-02-12}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
%
% \RequirePackage{amsmath}% \overrightarrow
% \RequirePackage{amssymb}% \curvearrowright
% \RequirePackage{bm} % recommended for bold math
%
\DeclareDocumentCommand{\MakeBoldUppercase}{ m }{
	\mathbf{\MakeUppercase{#1}}
}
\DeclareDocumentCommand{\MakeUpperBB}{ m }{
	\mathbb{\MakeUppercase{#1}}
}
\DeclareDocumentCommand{\MakeUpperCal}{ m }{
	\mathcal{\MakeUppercase{#1}}
}
\DeclareDocumentCommand{\MakeUpperFrak}{ m }{
	{\mathfrak{\MakeUppercase{#1}}}
}
\DeclareDocumentCommand{\overdoubleleftrightarrow}{ m }{
	{\overleftrightarrow{\overleftrightarrow{#1}}}
}
\DeclareDocumentCommand{\overrightleftrightarrow}{ m }{
	{\overrightarrow{\overleftrightarrow{#1}}}
}
\DeclareDocumentCommand{\overrightdoubleleftrightarrow}{ m }{
	{\overrightarrow{\overleftrightarrow{\overleftrightarrow{#1}}}}
}
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

%
%
% %%%%%  Generate variants  %%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{\__tensorstyles_set_scale:nnn}
% 		\begin{arguments}
%  		\item |grp-cmd_variant| for which the scaling will be set.
%  		\item |scale| the desired scale, eg, auto or none or big or Big...
%  		\item |delimiters-name| the name of the category of delimiters to scale.
% 		\end{arguments}
% 		Set the scale of a pair of delimiters .
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
% \tensorstyles_set_keys:nn #1:tensor, #2:keyval
\cs_new_protected:Npn \tensorstyles_set_keys:nn #1 #2 {
	%
	\tl_set:Nx \l_tmpa_tl { \tl_use:c { l__tensorstyles_tensor_#1_preset  } }
	\tl_set:Nx \l_tmpb_tl { \tl_use:c { l__tensorstyles_tensor_#1*_preset } }
	\use:c { __tensorstyles_tensor_define_local_preset_keys:n } { #1 }
	\keys_set:nn {tensorstyles/preset/#1} { #2 }

	\tl_if_eq:cnF { l__tensorstyles_tensor_#1_local_preset } { None } {
		\tl_set:Nx \l_tmpa_tl { \tl_use:c { l__tensorstyles_tensor_#1_local_preset } }
		\tl_set:cx { l__tensorstyles_tensor_#1_preset } { \tl_use:c { l__tensorstyles_tensor_#1_local_preset } }
	}

	\tl_if_eq:cnF { l__tensorstyles_tensor_#1*_local_preset } { None } {
		\tl_set:Nx \l_tmpb_tl { \tl_use:c { l__tensorstyles_tensor_#1*_local_preset } }
		\tl_set:cx { l__tensorstyles_tensor_#1*_preset } { \tl_use:c { l__tensorstyles_tensor_#1*_local_preset } }
	}

	\seq_if_in:NnTF \l__tensorstyles_tensor_variant_seq { #1 } {
		% True tensor
		\prop_set_eq:cc { l__tensorstyles_tensor_#1_user_keys_prop  } { c__tensorstyles_tensor_ \tl_use:N \l_tmpa_tl _pkg_keys_prop }
		\prop_set_eq:cc { l__tensorstyles_tensor_#1*_user_keys_prop } { c__tensorstyles_tensor_ \tl_use:N \l_tmpb_tl _pkg_keys_prop }

		\__tensorstyles_set_default_from_keyval:nVnn { #1  } \l_tmpa_tl { #2 } { tensor }
		\__tensorstyles_set_default_from_keyval:nVnn { #1* } \l_tmpb_tl { #2 } { tensor }
	}{
		% False tensor
		\seq_if_in:NnTF \l__tensorstyles_i_variant_seq { #1 }{
			% True I
			\prop_set_eq:cc { l__tensorstyles_tensor_#1_user_keys_prop  } { c__tensorstyles_i_ \tl_use:N \l_tmpa_tl _pkg_keys_prop }
			\prop_set_eq:cc { l__tensorstyles_tensor_#1*_user_keys_prop } { c__tensorstyles_i_ \tl_use:N \l_tmpb_tl _pkg_keys_prop }

			\__tensorstyles_set_default_from_keyval:nVnn { #1 } \l_tmpa_tl { #2 } { i }
			\__tensorstyles_set_default_from_keyval:nVnn { #1* } \l_tmpb_tl { #2 } { i }
		} {
			% False I
			\msg_error:nnxx { tensorstyles } { tensor-not-defined }
			{ \token_to_str:N #1  }
			{ \token_to_str:N \tensorsset }
		}
	}
}
\cs_generate_variant:Nn \tensorstyles_set_keys:nn { V }
% \cs_generate_variant:Nn \__tensorstyles_set_rubber_length:Nn { c }
% \cs_generate_variant:Nn \__tensorstyles_var_bool_seq:NNN { c }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

%
%
% %%%%%   Messages   %%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%
%
% \begin{implementation}
% 	\begin{function}[added= 2025-02-17]{messages}
% 		Set the messages that can be emitted.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
%    \begin{macrocode}
% \msg_new:nnnn { tensorstyles } { 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.
% }
\msg_new:nnn { tensorstyles } { rank_indices_missmatch }
	{ The~number~of~given~indices~and~rank~do~not~match~(#1) }
\msg_new:nnn { tensorstyles } { index-type-option-not-define }
	{ The~default-indices~is~only~accepting~contra~or~covariant~choice }
\msg_new:nnn { tensorstyles } { index-style-option-not-defined }
	{ Index~styles~(ie~contra-style~or~covariant-style)~on~accept~greek,~alph~or~arabic~choice }
%    \end{macrocode}
% 	\end{function}
% \end{implementation}

%
%
% %%%%%  Declaring \& Generate   %%%%%
% %%%%%  new group of commands  %%%%%
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \begin{implementation}
% 	\begin{macro}[added= 2025-02-17]{\tensorsset{all}}
% 		First setup of the options for 'all' commands.
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\@ifpackageloaded{mleftright}
{ \tensorsset{all}[scale-auto = mleftmright] }
{ \tensorsset{all}[scale-auto = leftright]   }
%    \end{macrocode}
% 	\end{macro}
% \end{implementation}
%
% \begin{implementation}
% 	\begin{macro}[added= 2025-02-17]{\DeclareTensorsCmd{\testCmd}}
% 		Declare the official commands of the package: testCmd
% 		\changes{v0.1.1.2}{2025-02-17}{original version}
% 		\TestFiles{tensorstyles-test-005}
%    \begin{macrocode}
\DeclareTensorsCmd{\tensor}[preset=full]
%    \end{macrocode}
% 	\end{macro}
% \end{implementation}

% \begin{implementation}
%    \begin{macrocode}
\endinput
%</package>
%    \end{macrocode}
% \end{implementation}

%
% \Finale