%
% Copyright (C) 1998-2023 Javier Bezos http://www.texnia.com
%
% This file may be distributed and/or modified under the conditions of
% the MIT License. A version can be found at the end of this file.
%
% Repository: https://github.com/jbezos/titlesec
%
% Notes
% ~~~~~
%
% The following tags are used:
% ttl@  : the generic tag used through the style
% ttlh@ : a shape definition
% ttlf@ : a macro containing the title format
% ttls@ : id. the title space
% ttlp@ : page key related macros
% ttll@ : level number
%
% The ttlf@ and ttls@ contains data in the form {..}{..}.
% Perhaps in future releases they should be converted
% to a prop-like list, similar to that proposed by the
% latex team.
%
% Admittedly, the current implementation seems too
% complicated, but that's necessary in order to provide
% certain compatibility with the sections as defined by the
% used class. Other packages opt for providing the sections
% as defined by standard classes ignoring the class; for
% instance sectsty which does a simple task in a simple and
% nice way. However, that was not my goal.
%
% Release
% ~~~~~~~

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{titlesec}[2023/10/27 v2.16 Sectioning titles]

% Initialization
% ~~~~~~~~~~~~~~

\newif\ifttl@ps
\ttl@psfalse

% The \ttl@label switch is used when printing the label in titles.
% A numberless variant makes it to true.
% There is a \ttl@toclabel as well, which is true iff the
% title is numbered; used in toc entries (except default part
% and chapter) and marks (only in titlesec pagestyles).

\newif\ifttl@label
\newif\ifttl@toclabel

\newbox\ttl@box

% A provision for the report style:

\@ifundefined{if@mainmatter}
  {\let\if@mainmatter\iftrue}{}

\@ifundefined{if@openright}
  {\let\if@openright\iftrue}{}

% and the ams styles as well

\@ifundefined{@chapapp}
  {\let\@chapapp\chaptername}{}

\def\ttl@trylist{\ttl@try{}}

\def\ttl@getkeys#1#2{%
  \if\expandafter @\@gobble#1@\@empty
    \edef\ttl@b{\expandafter\@gobble\string#1}%
    \let\ttl@a\ttl@b
  \else
    \ttl@keys
    \ttl@getkeys{#1}{#2}%
  \fi}

% A more meaningful error for \@notdefinable

\expandafter\AtEndOfPackage\expandafter{\expandafter
  \gdef\expandafter\@notdefinable\expandafter{\@notdefinable}}

\def\@notdefinable{%
  \PackageError{titlesec}%
    {Incompatible package}%
    {Titlesec cannot continue defining its own macros 
         because\MessageBreak
     \@backslashchar\reserved@a\space is already used by other package,
         the class\MessageBreak
     or the document.}}

%               +-----------------+
%               |  C L A S S E S  |
%               +-----------------+

\def\ttl@useclass#1#2{%
  \@ifstar
    {\ttl@labelfalse#1{#2}[]}%
    {\ttl@labeltrue\@dblarg{#1{#2}}}}

\def\ttl@straightclass{\ttl@useclass\ttl@straight@i}
\def\ttl@partclass{\ttl@useclass\ttl@part@i}
\def\ttl@topclass{\ttl@useclass\ttl@top@i}
\def\ttl@pageclass{\ttl@useclass\ttl@page@i}

% Here \scantokens is used to make sure the unescaped name
% has `letters' and no `others'. Mainly for hyperref, so there
% should be no problems.

\newcommand\titleclass[1]{%
  \edef\ttl@a{\expandafter\@gobble\string#1}%
  \ifx\scantokens\@undefined\else
    \scantokens\expandafter{\expandafter
      \def\expandafter\ttl@a\expandafter{\ttl@a}}%
  \fi
  \@ifnextchar[{\@tempswatrue\ttl@class@i{#1}}%
               {\@tempswafalse\ttl@class@ii{#1}}}

\def\ttl@class@i#1[#2]{%
  \@namedef{ttll@\ttl@a}{#2}%
  \expandafter\providecommand\csname\ttl@a title\endcsname{}%%%%
  \@ifundefined{ttl@toplevel}{}%
    {\expandafter\let\csname ttlss@\ttl@a\expandafter\endcsname
       \csname ttlss@\ttl@toplevel\endcsname}%
  \edef\ttl@toplevel{\ttl@a}%
  \ttl@class@ii{#1}}

\def\ttl@class@ii#1#2{%
  \@ifundefined{ttl@#2class}%
    {\PackageError{titlesec}{Unknown sectioning class}%
       {Valid names are top, page and straight}}%
    {\expandafter\let\csname ttl@compat\ttl@a\endcsname\relax
     \@ifundefined{\ttl@a mark}%
       {\@namedef{\ttl@a mark}{\@gobble}}%
       {}%
     \edef#1{%
       \expandafter\noexpand\csname ttl@#2class\endcsname{\ttl@a}}}%
  \if@tempswa
    \expandafter\@gobble
  \else  
    \expandafter\@firstofone
  \fi
    {\@ifnextchar[%
       {\ttl@class@iii}%
       {\@ifundefined{ttll@\ttl@a}%
          {\PackageError{titlesec}{Unknown sectioning level}%
            {\string\titleclass\space with no optional arguments\MessageBreak
             only changes the class of an *existing* level}}}}}

\def\ttl@class@iii[#1]{%
  \edef\ttl@b{\expandafter\@gobble\string#1}%
  \expandafter\let\csname ttlss@\ttl@a\expandafter\endcsname
     \csname ttlss@\ttl@b\endcsname
  \expandafter\edef\csname ttlss@\ttl@b\endcsname{\ttl@a}%
  \let\ttl@a\ttl@toplevel
  \count@\csname ttll@\ttl@toplevel\endcsname
  \ttl@class@iv}

\def\ttl@class@iv{%
  \@ifundefined{ttlss@\ttl@a}{}%
    {\advance\count@\@ne
     \edef\ttl@a{\csname ttlss@\ttl@a\endcsname}%
     \expandafter\edef\csname ttll@\ttl@a\endcsname{\the\count@}%
     \ttl@class@iv}}

% Typesetting Classes: General tools
% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
% The following command handles the *n spacing
% Some tricks are necessary to multiply a
% skip by a non integer number

\newskip\beforetitleunit
\beforetitleunit=1ex\@plus.3ex\@minus.06ex
\newskip\aftertitleunit
\aftertitleunit=1ex\@plus.1ex

\newdimen\ttl@plus
\newdimen\ttl@minus

\def\ttl@assign#1{%
  \@ifstar
    {\ttl@assign@i{#1}}%
    {\ttl@assign@d{#1}}}

\def\ttl@assign@i#1#2\relax#3{%
  \ttl@plus\z@
  \ttl@minus\z@
  \afterassignment\ttl@assign@ii
  \dimen@\the#3, % <- space 
  #1 =     #2\dimen@
     plus  #2\ttl@plus
     minus #2\ttl@minus}

\def\ttl@assign@ii#1 {% <- space
  \if#1,\else\afterassignment\ttl@assign@ii\fi
  \csname ttl@\string#1\endcsname}

\def\ttl@assign@d#1#2\relax#3{\setlength#1{#2}}

% To be used with \v/vspace to make them calc-savvy

\def\ttl@calc#1#2{%
  {\setlength\@tempskipa{#2}%
   #1\@tempskipa}}

\def\ttl@calcneg#1#2{%
  {\setlength\@tempskipa{#2}%
   #1{-\@tempskipa}}}

% Gets from ttls@ and passes the spacing parameters:

\def\ttl@startargs#1#2{% Get the first arguments, with the spacing
  \@ifundefined{ttlp@#2}%
     {\let\ttl@key@page\@empty}%
     {\ttlp@fetch{#2}}%
  \begingroup
    \def\ttl@b{ttls@#2}%
    \edef\ttl@key@numberless{\ifttl@label//\else/*\fi}%
    \def\ttl@a##1{\csname ttl@key@##1\endcsname}%  Used as elt in try
    \ttl@trylist
    \xdef\ttl@b{\ttl@c}%
  \endgroup
  \ifx\ttl@b\@empty
    \PackageError{titlesec}{Format/spacing not found}%
      {I was unable to find the format corresponding to #2.\MessageBreak
       Maybe you haven't set it with \string\titleformat\space and
       \string\titlespacing}
  \fi
  \expandafter#1\ttl@b{#2}}

% Used in ttl@select

\def\ttl@savefn#1[#2]#3{%
  \ifcase#1%
    \footnotemark[#2]%
    \gdef\ttl@fn{\footnotetext[#2]{#3}}%
  \else
    \footnotemark
    \gdef\ttl@fn{\footnotetext{#3}}%
  \fi}

\def\ttl@nest@error{%
  \PackageError{titlesec}{Nested titles}{Titles must not be nested}}

\def\ttl@hmode@error{%
  \PackageError{titlesec}{Entered in horizontal mode}
    {The <format> argument cannot contain horizontal material\MessageBreak
     such as text, \string\noindent, \string\makebox, etc.}}

% \ttl@select not only selects the right version to be
% used. It also take steps to ensure that a mark
% is not lost inside a box by saving it into \ttl@mk,
% which in turn is used by the sect and chap commands.

% As of 2019 and due the LaTex
% kernel modifies \markboth, we consider two possibilities (2.13).

\newif\ifttl@explicit

\def\ttl@gmk#1{\gdef\ttl@mk{#1}}

\def\ttl@select#1#2#3#4{%
  \ttl@Hy@saveanchor
  \global\let\ttl@mk\@empty  % global because of rigidchapters
  \global\let\ttl@fn\@empty
  \begingroup
   \if@inlabel\else % Keep item's \everypar
      \everypar{\setbox\z@\lastbox\ttl@strut}%
   \fi
   \let\ttl@straight@i\ttl@nest@error
   \let\ttl@top@i     \ttl@nest@error
   \let\ttl@part@i    \ttl@nest@error
   \let\ttl@page@i    \ttl@nest@error
   \let\ttl@newpage\newpage
   \def\newpage{\ttl@savewrite\ttl@newpage}%
   \expandafter\ifx\csname markboth \endcsname\relax
     \def\markboth##1##2{\protect\ttl@gmk{\protect\markboth{##1}{##2}}}%
     \def\markright##1{\protect\ttl@gmk{\protect\markright{##1}}}%
   \else
     \@namedef{markboth }##1##2{\protect\ttl@gmk{\markboth{##1}{##2}}}%
     \@namedef{markright }##1{\protect\ttl@gmk{\markright{##1}}}%
   \fi
   \def\@mkboth##1##2{\protect\ttl@gmk{\protect\@mkboth{##1}{##2}}}%
   \protected\def\footnote{\@ifnextchar[%
     {\ttl@savefn\z@}{\ttl@savefn\@ne[]}}%
   \edef\ttl@key@numberless{\ifttl@label//\else/*\fi}%
   \def\ttl@b{ttlf@#1}%
   \def\ttl@a##1{\csname ttl@key@##1\endcsname}% Used as elt in try
   \ttl@trylist
   \ifx\ttl@c\@empty
     \PackageError{titlesec}{No format for this command}%
       {If you (re)set the class of a sectioning command, you may\MessageBreak
        you may need to (re)define its format with \string\titleformat}%
   \fi
   \ifttl@explicit
     \def\ttl@passexplicit{\ttl@case{#4}}%
     \ttl@c{#4}{#2}{#3}{}% ttl@c is returned by ttl@try with ttlf@...
   \else     
     \let\ttl@passexplicit\ttl@case
     \ttl@c{#2}{#3}{#4}% ttl@c is returned by ttl@try with ttlf@...
   \fi
  \endgroup}

\let\ttl@savewrite\@empty

\def\ttl@finmarks{%
  \ttl@savewrite
  \ttl@mk  % Contains a possible mark, returned by \ttl@select
  \ttl@fn} % And a footnote

\def\ttl@try#1{%
  \edef\ttl@c{#1}%  #1 is a list in the form \ttl@a{key}\ttl@a{key}
  \@ifundefined{\ttl@b\ttl@c}{}{%
    \edef\ttl@c{\expandafter\noexpand\csname\ttl@b\ttl@c\endcsname}%
    \def\ttl@a##1{\csname ttl@extra@##1\endcsname}%
    #1%
    \let\ttl@try\@gobble}} % locally modified to `break' testings

% \ttl@write writes marks and toc. tocdepth is taken care of when
% the toc is typesetted and not here.  Used always through
% ttl@savewrite, which is reset to \@empty to avoid duplicated
% calls. 

\def\ttl@write#1#2{%
  \ttl@blinemarks
  \csname#1mark\endcsname{#2}%
  \def\ttl@a{\protect\numberline{\@nameuse{the#1}}}%
  \@nameuse{ttl@toc#1}% eg, \ttl@tocpart modifies \ttl@a
  \ttl@addcontentsline{#1}{#2}% Depends on toctitles, uses \ttl@a
  \ttl@elinemarks
  \global\ttl@toclabelfalse
  \global\let\ttl@savewrite\@empty}

\newif\ifttl@premark % to be used in ttlps.def
\ttl@premarkfalse

% 2019-06-20. Added the \lastskip stuff, because a mark 'forgets' the
% last skip.
  
\def\ttl@premark#1#2{%
  \let\ttl@lastskip\relax
  \ifvmode
    \ifdim\lastskip=\z@\else
      \edef\ttl@lastskip{\the\lastskip}% 
      \vskip-\ttl@lastskip\relax
    \fi
  \fi
  \protected@xdef\ttl@prevmarks{\ttl@marks}%
  \ttl@blinemarks
  \csname#1mark\endcsname{#2}%
  \ttl@elinemarks
  \ifx\ttl@lastskip\relax\else
    \vskip\ttl@lastskip\relax
  \fi
  \gdef\ttl@prevmarks{\ttl@marks}}

% Must be preceded by a default \ttl@savewrite, which is used
% in starred variants--\@empty in top and straight classes.
% In straight class, it is preceded by the setting of
% prev marks to provide a "fixed" top mark. Otherwise,
% the default prev mark (= curr mark) is used (restored
% after ttl@labelling in straight). This is the command
% to be hacked if you want to change the behaviour of
% starred variants.

\def\ttl@labelling#1#2{%
  \let\ttl@Hy@saveanchor\@empty
  \ifttl@label  %  1st - if star
    \def\ttl@savewrite{\ttl@write{#1}{#2}}%
    \@nameuse{ttl@#1label}%  eg, sets if mainmatter in chapter.
    \ifttl@label  % 2nd - eg, if not main matter
      \ifnum\@nameuse{ttll@#1}>\c@secnumdepth\relax
        \ttl@labelfalse     % 3rd - if too deep
      \else
        \ttl@Hy@refstepcounter{#1}%
        \@nameuse{ttl@#1out}%
      \fi
    \fi
  \fi
  \let\ifttl@toclabel\ifttl@label
  \ifx\ttl@savewrite\@empty\else % If marks
    \ifttl@ps
      \ifttl@premark
        \global\ttl@premarkfalse
      \else % if no \pretitlemark
        \ttl@premark{#1}{#2}%
      \fi
    \fi
    \ifttl@label\else\ttl@Hy@steplink{#1}\fi
  \fi}

% Executed by ttl@labelling if the name of section is chapter:

\def\ttl@chapterlabel{\if@mainmatter\else\ttl@labelfalse\fi}

% Executed by ttl@labelling if chapter has a number. Note
% you can define messages for other sectioning levels (eg,
% \ttl@sectionout).

\def\ttl@chapterout{\typeout{\chaptertitlename\space\thechapter.}}

% Straight class
% ~~~~~~~~~~~~~
% Default for nobottomtitles. Changed by nobottomtitles*

\def\ttl@addstretch{\advance\@tempskipa-\pagestretch}

% 1:name 2:level 3:indent 4:before 5:after 6:afind [7]:cap 8:title
% The second argument of ttl@sect is the level, which
% is empty if the star version is used. In this case
% neither the toc nor the marks are written.

\def\ttl@straight@i#1[#2]#3{%
  \def\@currentlabelname{#2}% for nameref
  \gdef\ttl@savemark{\csname#1mark\endcsname{#3}}%
  \let\ttl@savewrite\@empty
  \def\ttl@savetitle{#3}%
  \gdef\thetitle{\csname the#1\endcsname}%
  \if@noskipsec \leavevmode \fi
  \par
  \ttl@labelling{#1}{#2}%
  \ttl@startargs\ttl@straight@ii{#1}{#3}}

% 1:left 2:right 3:before 4:after 5:afterindent 6:name 7:title

\def\ttl@straight@ii#1#2#3#4#5#6#7{%
  \ttl@assign\@tempskipa#3\relax\beforetitleunit
  \@ifundefined{ttl@ps@#6}{}%
    {\PackageWarning{titlesec}{Page style in straight class ignored}}%
  \if@nobreak
    \ttl@titlespace{\@tempskipa}%
  \else
    \@ifundefined{#6break}%
      {\addpenalty{\@secpenalty}}%
      {\csname#6break\endcsname}%
    \addvspace{\@tempskipa}%
    \ifdim\bottomtitlespace<\z@
    \else
      \begingroup
       \@tempskipb\pagegoal
       \@tempskipa\pagegoal
       \ttl@addstretch  % \relax if nobottomtitle*
       \advance\@tempskipa-\bottomtitlespace\relax % not a register
       \pagegoal\@tempskipa
       \def\@textbottom{\vskip\z@\@plus.0001fil}%
       \penalty9999
       \pagegoal\@tempskipb
      \endgroup
    \fi
  \fi
  \@afterindenttrue
  \ifcase#5 \@afterindentfalse\fi
  \ttl@assign\@tempskipb#4\relax\aftertitleunit
  \ttl@select{#6}{#1}{#2}{#7}%
  \ttl@finmarks
  \@ifundefined{ttlp@#6}{}{\ttlp@write{#6}}%
  \if@noskipsec
    \global\@nobreakfalse
    \everypar{%
      \if@noskipsec
        \global\@noskipsecfalse
        \clubpenalty\@M
        \hskip-\parindent
        \begingroup
          \@svsechd\unskip{\hspace{\@tempskipb}}%
        \endgroup
      \else
        \clubpenalty\@clubpenalty\everypar{}%
      \fi}%
  \else
    \par\nobreak
    \vspace{\@tempskipb}%
    \@afterheading
  \fi
  \ignorespaces}

% Part class
% ~~~~~~~~~~

\providecommand\partmark[1]{\markboth{}{}}

\def\ttl@part@i#1[#2]#3{%
  \gdef\ttl@savemark{\csname#1mark\endcsname{#3}}%
  \ifx\ttl@notocparts\@undefined
    \def\ttl@savewrite{\ttl@write{#1}{#3}}% Not #2!
  \else
    \let\ttl@savewrite\@empty
  \fi
  \def\ttl@savetitle{#3}%
  \ttl@labelling{#1}{#2}%
  \ttl@startargs\ttl@part@ii{#1}{#3}}

\def\ttl@part@ii#1#2#3#4#5#6#7{%
  \ttl@assign\@tempskipa#3\relax\beforetitleunit
  \vspace*{\@tempskipa}%
  \@ifundefined{ttl@ps@#6}{}%
    {\PackageWarning{titlesec}{Page style in part class ignored}}%
  \global\@afterindenttrue
  \ifcase#5 \global\@afterindentfalse \fi
  \ttl@assign\@tempskipb#4\relax\aftertitleunit 
  \ttl@select{#6}{#1}{#2}{#7}%
  \ttl@finmarks
  \@ifundefined{ttlp@#6}{}{\ttlp@write{#6}}%
  \par\nobreak
  \vspace{\@tempskipb}%
  \@afterheading}

% Page class
% ~~~~~~~~~~

\def\ttl@page@i#1[#2]#3{%
  \gdef\ttl@savemark{\csname#1mark\endcsname{#3}}%
  \ifx\ttl@notocparts\@undefined
    \def\ttl@savewrite{\ttl@write{#1}{#3}}% Not #2!
  \else
    \let\ttl@savewrite\@empty
  \fi
  \def\ttl@savetitle{#3}%
  \ttl@labelling{#1}{#2}%
  \ttl@startargs\ttl@page@ii{#1}{#3}}

\def\ttl@page@ii#1#2#3#4#5#6#7{%
  \ttl@assign\@tempskipa#3\relax\beforetitleunit
  \if@openright
    \cleardoublepage
  \else
    \clearpage
  \fi
  \@ifundefined{ttl@ps@#6}%
    {\thispagestyle{plain}}%
    {\thispagestyle{\@nameuse{ttl@ps@#6}}}%
  \if@twocolumn
    \onecolumn
    \@tempswatrue
  \else
    \@tempswafalse
  \fi
  \vspace*{\@tempskipa}%
  \@afterindenttrue
  \ifcase#5 \@afterindentfalse\fi
  \ttl@assign\@tempskipb#4\relax\aftertitleunit
  \ttl@select{#6}{#1}{#2}{#7}%
  \ttl@finmarks
  \@ifundefined{ttlp@#6}{}{\ttlp@write{#6}}%
  \vspace{\@tempskipb}%
  \newpage
  \if@twoside
    \if@openright
      \null
      \@ifundefined{ttl@ps@#6}%
        {\thispagestyle{empty}}%
        {\thispagestyle{\@nameuse{ttl@ps@#6}}}%
      \newpage
    \fi
  \fi
  \if@tempswa
    \twocolumn
  \fi
  \ignorespaces}

% Top class and some makechapterhead stuff
% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
%
% \ttl@mkchap is the new make(s)chapterhead.

\def\ttl@mkchap#1#2#3#4#5#6#7{%
  \gdef\ttl@savemark{\csname#6mark\endcsname{#7}}%
  \let\ttl@savewrite\@empty
  \let\ttl@Hy@saveanchor\@empty
  \@ifundefined{ttl@ps@#6}{}%
    {\thispagestyle{\@nameuse{ttl@ps@#6}}}%
  \let\ifttl@toclabel\ifttl@label
  \ttl@mkchap@i{#1}{#2}{#3}{#4}{#5}{#6}{#7}}

% But \ttl@mkchap@i is used by both makechapterhead and
% the top class.

\def\ttl@mkchap@i#1#2#3#4#5#6#7{%
  \ttl@assign\@tempskipa#3\relax\beforetitleunit
  \vspace*{\@tempskipa}%
  \global\@afterindenttrue
  \ifcase#5 \global\@afterindentfalse\fi
  \ttl@assign\@tempskipb#4\relax\aftertitleunit
  \ttl@topmode{\@tempskipb}{%
    \ttl@select{#6}{#1}{#2}{#7}}%
  \ttl@finmarks  % Outside the box!
  \@ifundefined{ttlp@#6}{}{\ttlp@write{#6}}}

\def\ttl@top@i#1[#2]#3{%
  \gdef\ttl@savemark{\csname#1mark\endcsname{#3}}%
  \let\ttl@savewrite\@empty
  \def\ttl@savetitle{#3}%
  \ttl@labelling{#1}{#2}%
  \ttl@startargs\ttl@top@ii{#1}{#3}}

\def\ttl@top@ii#1#2#3#4#5#6#7{%
  \@ifundefined{#6break}%
    {\if@openright
       \cleardoublepage
     \else
       \clearpage
     \fi}%
    {\csname#6break\endcsname}%
  \@ifundefined{ttl@ps@#6}%
    {\thispagestyle{plain}}%
    {\thispagestyle{\@nameuse{ttl@ps@#6}}}%
  \global\@topnum\z@
  \@ifundefined{#6tolists}%
    {\addtocontents{lof}{\protect\ttl@tocsep}%
     \addtocontents{lot}{\protect\ttl@tocsep}}
    {\@nameuse{#6tolists}}%
  \if@twocolumn
    \@topnewpage[\ttl@mkchap@i{#1}{#2}{#3}{#4}{#5}{#6}{#7}]%
  \else
    \ttl@mkchap@i{#1}{#2}{#3}{#4}{#5}{#6}{#7}%
    \@afterheading
  \fi
  \ignorespaces}

%     \def\ttl@noskipsectrue{%
%       \if@noskipsec
%     \PackageError{titlesec}{Invalid shape for top class}%
%        {The selected shape only makes sense when merged into\MessageBreak
%         a paragraph. That is impossible in the top class}%
%   \else

\newcommand\chaptertitlename{\@chapapp}
\def\ttl@tocsep{\addvspace{10\p@}}

%               +-----------------+
%               |   S H A P E S   |
%               +-----------------+
%               
% Reformatting Titles: Interface
% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

% The surrounding space is stored in a macro
% named \ttls@<section> whose content is
% {left}{right}{before}{after}{afterindent}.
% But if there is the page key, the name is
% \ttls@<section>/<page>

\newcommand\titlespacing{%
  \@ifstar{\ttl@spacing@i{\z@}}{\ttl@spacing@i{\@ne}}}

\def\ttl@spacing@i#1#2#3#4#5{%
  \ttl@getkeys{#2}{titlesec}%
  \@ifnextchar[{%
     \ttl@spacing@ii{#1}{#3}{#4}{#5}%
   }{%
     \ttl@spacing@ii{#1}{#3}{#4}{#5}[\z@]}}

\def\ttl@spacing@ii#1#2#3#4[#5]{%
   \expandafter\def\csname ttls@\ttl@a\endcsname
       {{#2}{#5}{#3}{#4}{#1}}}

% The section name is built in \ttl@a.
% The format is stored in a macro named \ttlf@<section>,
% or \ttlf@<section>/<page> if there is the page spec,
% or \ttlf@.../* if numberless is true
% whose content is
%  \ttl@<shape>{format}{label}{sep}{before}{after}

\newtoks\ttl@toksa

\newcommand\titleformat{%
  \@ifstar{\ttl@format@s}%
          {\ttl@format@i}}

\def\ttl@format@s#1#2{%
  \edef\ttl@a{\expandafter\@gobble\string#1}%
  \@ifundefined{ttlf@\ttl@a}%
    {\PackageError{titlesec}{Not allowed in `easy' settings}
       {The sectiong command you are trying to redefine\MessageBreak
        is not handled by the starred variant (eg, \string\part)}}{}
  \expandafter\expandafter\expandafter
  \ttl@format@si\csname ttlf@\ttl@a \endcsname
  {#2}}

\def\ttl@format@si#1#2#3#4#5#6#7{%
  \@namedef{ttlf@\ttl@a}{#1{#7}{#3}{#4}{#5}{#6}}}

\def\ttl@format@i#1{%
  \@ifnextchar[{\ttl@format@ii{#1}}{\ttl@format@ii{#1}[hang]}}

\def\ttl@format@ii#1[#2]#3#4#5#6{%
  \ttl@getkeys{#1}{titlesec}%
  \ttl@toksa{{#3}{#4}{#5}{#6}}% Save  arguments
  \@ifnextchar[{%
    \ttl@format@iii{#2}%
  }{%
    \ttl@format@iii{#2}[]}}

% First, we get the shape -- if not defined it loads
% the corresponding file.

\def\ttl@format@iii#1[#2]{%
  \@ifundefined{ttlh@#1}{%
    \begingroup
    \makeatletter
    \InputIfFileExists{#1.tss}{}{%
      \@ifundefined{ttlhx@#1}%
        {\PackageError{titlesec}{Unknown shape}%
           {Shapes are defined in files with extension tss\MessageBreak
            Either you have misspelled the shape\MessageBreak
            or there is no a #1.tss file}}%
        {\global\expandafter
         \let\csname ttlh@#1\expandafter\endcsname
           \csname ttlhx@#1\endcsname}}%
    \endgroup}{}%
  \@temptokena{#2}%
  \ifttl@explicit
    \edef\ttl@b{%
      \def\expandafter\noexpand\csname ttlf@\ttl@a\endcsname####1%
      {\expandafter\noexpand\csname ttlh@#1\endcsname
       \the\ttl@toksa{\the\@temptokena}}}%
  \else
    \edef\ttl@b{%
      \def\expandafter\noexpand\csname ttlf@\ttl@a\endcsname
      {\expandafter\noexpand\csname ttlh@#1\endcsname
       \the\ttl@toksa{\the\@temptokena}}}%
  \fi
  \ttl@b
  \csname ttl@compat\ttl@a\endcsname}

% Styles
% ~~~~~~
%
% \ttl@<shape> and \ttlh@<shape> take the following eight
% arguments:
% {format}{label}{sep}{before}{after}{left}{right}{title}
% where before and after refer to the format.
% With the option explicit, #4 contains the title and #8 is
% empty.

\def\ttl@strut{\strut}

\def\ttlh@display#1#2#3#4#5#6#7#8{%
  \gdef\ttl@makeline##1{\ttl@calc\hspace{#6}##1\ttl@calc\hspace{#7}}%
  \setlength\leftskip{#6}%
  \setlength\rightskip{#7}%
  \interlinepenalty\@M
  \ttl@changecentercr
  \ttl@defnostruts
  \ttl@beginlongest
    #1\ifhmode\ttl@hmode@error\fi
    \ttl@glcmds
    \parindent\z@
    \ifttl@label
      {#2\ttl@strut\@@par}\nobreak\ttl@calc\vspace{#3}%
    \fi
    #4{#8}%
   \kern\z@\ttl@strut\@@par
   \nobreak\ttl@midlongest#5\@@par
  \ttl@endlongest}

\def\ttlh@hang#1#2#3#4#5#6#7#8{%
  \gdef\ttl@makeline##1{\ttl@calc\hspace{#6}##1\ttl@calc\hspace{#7}}%
  \setlength\leftskip{#6}%
  \setlength\rightskip{#7}%
  \interlinepenalty\@M
  \ttl@changecentercr
  \ttl@defnostruts
  \ttl@beginlongest
  #1{\ifhmode\ttl@hmode@error\fi
     \ttl@glcmds
     \parindent\z@
     \begingroup
       \ifttl@label
          \noindent
          \sbox\z@{#2\ttl@strut\ttl@calc\hspace{#3}}%
          \hangindent\wd\z@
          \box\z@
       \fi
       #4{#8}%
       \kern\z@\ttl@strut\@@par
     \endgroup
     \nobreak\ttl@midlongest#5\@@par}%
  \ttl@endlongest}

\def\ttlh@runin#1#2#3#4#5#6#7#8{%
  \global\@noskipsectrue
  \gdef\ttl@makeline##1{##1}%
  \ttl@changecentercr
  \ttl@defnostruts
  #1{\ifhmode\ttl@hmode@error\fi
     \global\sbox\ttl@box{%
       \ttl@calc\hspace{#6}%
       \ifttl@label{\ttl@strut#2}\ttl@calc\hspace{#3}\fi
       #4{#8}#5\unskip}}%
    \gdef\@svsechd{\unhbox\ttl@box}}

% ----------

\gdef\ttlhx@block#1#2#3#4#5#6#7#8{%
  \gdef\ttl@makeline##1{\ttl@calc\hspace{#6}##1\ttl@calc\hspace{#7}}%
  \setlength\leftskip{#6}%
  \setlength\rightskip{#7}%
  \interlinepenalty\@M
  \ttl@changecentercr
  \ttl@defnostruts
  \ttl@beginlongest
    #1% \ifhmode\ttl@hmode@error\fi
    \ttl@glcmds
    \parindent\z@
    \leavevmode
    \ifttl@label
       {#2}%
       \setlength\@tempskipa{#3}%
       \ifdim\@tempskipa=\z@\else\ttl@calc\hspace{#3}\fi
    \fi
    #4{#8}%
    \kern\z@\ttl@strut\@@par
    \nobreak\ttl@midlongest#5\@@par
  \ttl@endlongest}
  

\gdef\ttlhx@frame#1#2#3#4#5#6#7#8{%
  \def\ttl@filleft##1{\hfill}%
  \def\ttl@filright##1{\hfill}%
  \gdef\ttl@makeline##1{%
    \ttl@calc\hspace{#6}##1\ttl@calc\hspace{#7}}%
  \interlinepenalty\@M
  \ttl@changecentercr
  \ttl@defnostruts
  #1\ifhmode\ttl@hmode@error\fi
  \parindent\z@
  \leavevmode
  \@tempdima\fboxrule
  \addtolength\@tempdima{#3}%
  \setlength\leftskip{#6}%
  \setlength\rightskip{#7}%
  \lower\@tempdima\hbox{%
    \everypar{}%
    \setbox\z@\hbox{#2}%  
    \addtolength\hsize{-#6}%
    \addtolength\hsize{-#7}%
    \@tempdima\dp\z@ %  2002/3/22
    \advance\@tempdima.5\ht\z@
    \vbox{%
        \hbox to \hsize{%
          \leaders\hrule\@height\fboxrule\ttl@filleft{#3}%
          \ifttl@label\lower.5\ht\z@\box\z@\fi
          \leaders\hrule\@height\fboxrule\ttl@filright{#3}}%
        \vskip-\lineskip
        \ifttl@label\vskip-\@tempdima\fi
        \hbox{%
          \vrule\@width\fboxrule
          \kern-\fboxrule
          \vbox{%
             \ttl@calc\vspace{#3}%
             \leavevmode
	         \addtolength\leftskip {#3}\addtolength\leftskip{-#6}%
	         \addtolength\rightskip{#3}\addtolength\rightskip{-#7}%
	         \ttl@strut#4{#8}\kern\z@\ttl@strut\@@par
             \ttl@calc\vspace{#3}}%
          \kern-\fboxrule
          \vrule\@width\fboxrule}%
       \hrule\@height\fboxrule}}%
	   \@@par\nobreak#5\@@par}

\gdef\ttlhx@leftmargin#1#2#3#4#5#6#7#8{%
  \global\@noskipsectrue
  \addtolength\@tempskipb{#6}%
  \xdef\ttl@makeline##1{\hskip-\the\@tempskipb\relax##1}%
  \leftskip\z@skip
  \rightskip\z@skip
  \ttl@changecentercr
  \ttl@defnostruts
  #1\ifhmode\ttl@hmode@error\fi
  \parindent\z@
  \global\setbox\ttl@box\vtop{%
    \setlength\hsize{#6}%
    \linewidth\hsize
    \everypar{}%
    \color@begingroup
    \ifttl@label{\ttl@strut#2\ttl@strut}\ttl@calc\hspace{#3}\fi
	   \ttl@strut#4{#8}\kern\z@\ttl@strut\@@par
    \color@endgroup}%
  \advance\@tempskipa\ht\ttl@box
  \advance\@tempskipa\dp\ttl@box
  \advance\@tempskipa-\pagegoal
  \advance\@tempskipa\pagestretch
  \@tempskipb\pagegoal
  \pagegoal-\@tempskipa
  \ifdim\bottomtitlespace<\z@\else
    \def\@textbottom{\vskip\z@\@plus.0001fil}%
  \fi
  \penalty9999
  \pagegoal\@tempskipb
  \dp\ttl@box=\z@
  \gdef\@svsechd##1##2{%   
    \llap{\box\ttl@box##2}%
    \if@afterindent\hskip\parindent\fi
    #5}}

\let\ttlhx@margin\ttlhx@leftmargin

\gdef\ttlhx@rightmargin#1#2#3#4#5#6#7#8{%
  \global\@noskipsectrue
  \addtolength\@tempskipb{#6}%
  \xdef\ttl@makeline##1{##1\hskip-\the\@tempskipb}%
  \leftskip\z@skip
  \rightskip\z@skip
  \ttl@changecentercr
  \ttl@defnostruts
  #1\ifhmode\ttl@hmode@error\fi
  \parindent\z@
  \global\setbox\ttl@box\vtop{%
     \setlength\hsize{#6}%
     \linewidth\hsize
     \everypar{}%
     \color@begingroup
     \ifttl@label{\ttl@strut#2\ttl@strut}\ttl@calc\hspace{#3}\fi
	    \ttl@strut#4{#8}\kern\z@\ttl@strut\@@par
     \color@endgroup}%
  \advance\@tempskipa\ht\ttl@box
  \advance\@tempskipa\dp\ttl@box
  \advance\@tempskipa-\pagegoal
  \advance\@tempskipa\pagestretch
  \@tempskipb\pagegoal
  \pagegoal-\@tempskipa
  \ifdim\bottomtitlespace<\z@\else
    \def\@textbottom{\vskip\z@\@plus.0001fil}%
  \fi
  \penalty9999
  \pagegoal\@tempskipb
  \dp\ttl@box=\z@  
  \gdef\@svsechd##1##2{%
    \rlap{\hskip\textwidth##2\box\ttl@box}%
    \if@afterindent\hskip\parindent\fi}}

\gdef\ttlhx@wrap#1#2#3#4#5#6#7#8{%
  \global\@noskipsectrue
  \gdef\ttl@makeline##1{##1}%
  \ttl@changecentercr
  \ttl@defnostruts
  \begingroup
    #1\ifhmode\ttl@hmode@error\fi
    \titlewidth\z@
    \def\\{\@ifstar{\@ifnextchar[{\ttl@bs}{\newline}}%
                   {\@ifnextchar[{\ttl@bs}{\newline}}}%
    \def\ttl@bs[##1]{\newline}%
    \let\@centercr\\%
    \advance\rightskip 1\leftskip plus 1fil
    \leftskip=\z@
    \parindent\z@
    \let\iftitlemeasuring\@firstoftwo
    \global\setbox\ttl@box\vtop{\setlength\hsize{#6}%
      \color@begingroup
      \ifttl@label{#2}\ttl@calc\hspace{#3}\fi
      #4{#8}\kern\z@\ttl@strut
      \@@par
      \color@endgroup}%
    \let\iftitlemeasuring\@secondoftwo
    \ttl@boxprocess
    \global\titlewidth\titlewidth
    \global\titlewidthfirst\titlewidthfirst
    \global\titlewidthlast\titlewidthlast
  \endgroup
  \edef\ttl@maxdimen{\the\titlewidth}%
  #1\ifhmode\ttl@hmode@error\fi
  \global\setbox\ttl@box\vtop{\setlength\hsize{\ttl@maxdimen}%
    \color@begingroup
    \ifttl@label{#2}\ttl@calc\hspace{#3}\fi#4{#8}\kern\z@\ttl@strut
    \@@par
    \color@endgroup}%
  \advance\@tempskipa1.5\baselineskip
  \advance\@tempskipa\ht\ttl@box
  \advance\@tempskipa\dp\ttl@box
  \advance\@tempskipa-\pagegoal
  \advance\@tempskipa\pagestretch
  \@tempskipb\pagegoal
  \pagegoal-\@tempskipa
  \ifdim\bottomtitlespace<\z@\else
    \def\@textbottom{\vskip\z@\@plus.0001fil}%
  \fi
  \penalty9999
  \pagegoal\@tempskipb
  \@tempdima\ht\ttl@box \advance\@tempdima\dp\ttl@box
  \@tempdimb\@tempdima
  \divide\@tempdima\baselineskip \count@\@tempdima
  \advance\count@
    \ifdim\@tempdimb<\the\count@.5\baselineskip\@ne\else\tw@\fi
  \dp\ttl@box=\z@
  \xdef\@svsechd##1##2{%
    \noexpand\llap{\box\ttl@box##2}%
    \setbox\z@\hbox{\hskip\ttl@maxdimen\relax##2}%
    \global\hangindent\wd\z@
    \global\hangafter-\the\count@\relax}}

\gdef\ttlhx@drop#1#2#3#4#5#6#7#8{%
  \global\@noskipsectrue
  \gdef\ttl@makeline##1{##1}%
  \ttl@changecentercr
  \ttl@defnostruts
  #1\ifhmode\ttl@hmode@error\fi
  \parindent\z@
  \global\setbox\ttl@box\vtop{\setlength\hsize{#6}%
    \color@begingroup
    \ifttl@label{#2}\ttl@calc\hspace{#3}\fi
    #4{#8}\kern\z@\ttl@strut
    \@@par
    \color@endgroup}%
  \advance\@tempskipa1.5\baselineskip
  \advance\@tempskipa\ht\ttl@box
  \advance\@tempskipa\dp\ttl@box
  \advance\@tempskipa-\pagegoal
  \advance\@tempskipa\pagestretch
  \@tempskipb\pagegoal
  \pagegoal-\@tempskipa
  \ifdim\bottomtitlespace<\z@\else
    \def\@textbottom{\vskip\z@\@plus.0001fil}%
  \fi
  \penalty9999
  \pagegoal\@tempskipb
  \@tempdima\ht\ttl@box \advance\@tempdima\dp\ttl@box
  \@tempdimb\@tempdima
  \divide\@tempdima\baselineskip \count@\@tempdima
  \advance\count@
  \ifdim\@tempdimb<\the\count@.5\baselineskip\@ne\else\tw@\fi
  \dp\ttl@box=\z@
  \xdef\@svsechd##1##2{%
    \noexpand\llap{\box\ttl@box##2}%
    \setbox\z@\hbox{\noexpand\ttl@calc\noexpand\hspace{#6}\relax##2}%
    \global\hangindent\wd\z@
    \global\hangafter-\the\count@\relax}}

%               +-----------------+
%               |    T O O L S    |
%               +-----------------+
%
% calcwidth
% ~~~~~~~~~
% Implemented after code from soul (but much modified...)

\newdimen\titlewidth
\newdimen\titlewidthlast
\newdimen\titlewidthfirst

\let\ttl@glcmds\relax
\let\ttl@beginlongest\@empty
\let\ttl@midlongest\@empty
\let\ttl@endlongest\@empty
\let\iftitlemeasuring\@secondoftwo

\def\ttl@xbeginlongest#1\ttl@endlongest{%
  \titlewidth\z@
  \titlewidthlast\z@
  \let\iftitlemeasuring\@firstoftwo
  \setbox\ttl@box\vbox{%
    \def\ttl@glcmds{%
      \def\\{\@ifstar{\@ifnextchar[{\ttl@bs}{\newline}}%
                     {\@ifnextchar[{\ttl@bs}{\newline}}}%
      \def\ttl@bs[####1]{\newline}%
      \let\@centercr\\%
      \def\ttl@midlongest####1\@@par{}% Very dirty...
      \advance\rightskip 1\leftskip plus 1fil
      \leftskip=\z@}%
    #1}%
  \let\iftitlemeasuring\@secondoftwo
  \ttl@boxprocess
  #1}

\def\ttl@boxprocess{%
  \setbox\ttl@box=\vbox{%
    \unvcopy\ttl@box
    \unskip\unpenalty
    \global\setbox\@ne=\lastbox}%
  \ifvoid\@ne
  \else
    \setbox\tw@=\hbox{\hskip-\leftskip\unhbox\@ne\hskip-\rightskip}%
    \titlewidthfirst\wd\tw@
    \ifdim\titlewidth<\titlewidthfirst
	  \titlewidth\titlewidthfirst
	\fi
    \ifdim\titlewidthlast=\z@
      \titlewidthlast\titlewidthfirst
    \fi
    \expandafter\ttl@boxprocess
  \fi}

% Rules
% ~~~~~

\providecommand\titleline{%
  \@ifstar{\ttl@line@i{\hb@xt@\titlewidth}}%
          {\ttl@line@i{}}}

\def\ttl@line@i#1{%
  \@ifnextchar[{\ttl@line{#1}}{\ttl@line{#1}[s]}}

\def\ttl@line#1[#2]#3{%
  \vskip\topskip
  \hrule \@height \z@
  \nobreak
  \vskip-\topskip
  \begingroup
    \parindent\z@
    \everypar{}%
    \leftskip\z@
    \rightskip\z@   %  #1 is either \hb@xt@\titlewidth or empty:
    \@makebox[\hsize][#2]{\ttl@makeline{#1{#3}}}%
    \par
  \endgroup
  \hrule height \z@
  \nobreak}

\providecommand\titlerule{\@ifstar{\ttl@row}{\ttl@rule}}

\let\ttl@leaders\xleaders % For titletoc compatibility

\def\ttl@row{\@ifnextchar[{\ttl@row@i}{\ttl@row@i[\wd\z@]}}
\def\ttl@row@i[#1]#2{%
  \ifvmode\expandafter\titleline\fi
  {\sbox\z@{#2}%
   \ttl@calcneg\hspace{#1}%
   \hskip\wd\z@
   \ttl@leaders\hb@xt@#1{\hss\box\z@}%
   \hfill\kern\z@}}

\def\ttl@rule{\@ifnextchar[{\ttl@rule@i}{\ttl@rule@i[.4\p@]}}
\def\ttl@rule@i[#1]{%
  \ifvmode\expandafter\titleline\fi
  {\leaders\hrule height #1\hfill\kern\z@}}

% Par shapes and space
% ~~~~~~~~~~~~~~~~~~~~

\providecommand\filright{%
  \gdef\ttl@filleft##1{\hskip##1}%
  \gdef\ttl@filright##1{\hfill}%
  \let\\\@centercr
  \advance\rightskip\z@ \@plus 1fil\relax}
\providecommand\filleft{%
  \gdef\ttl@filleft##1{\hfill}%
  \gdef\ttl@filright##1{\hskip##1}%
  \let\\\@centercr
  \advance\leftskip\z@ \@plus 1fil
  \parfillskip\z@}
\providecommand\filcenter{\filleft\filright
  \gdef\ttl@filleft##1{\hfill}}
\providecommand\fillast{%
  \gdef\ttl@filleft##1{\hfill}%
  \gdef\ttl@filright##1{\hfill}%
  \let\\\@centercr
  \filleft\advance\rightskip\z@ \@plus -1fil
  \parfillskip\z@ \@plus 2fil\relax}
\newcommand\filinner{%
  \if@twoside
    \ifodd\count\z@\filleft\else\filright\fi
  \else
    \filleft
  \fi}
\newcommand\filouter{%
  \if@twoside
    \ifodd\count\z@\filright\else\filleft\fi
  \else
    \filright
  \fi}

\newcommand\wordsep{\fontdimen\tw@\font \@plus
  \fontdimen\thr@@\font \@minus \fontdimen4\font}

% Struts.
% ~~~~~~
% A way to remove the struts added by styles. May be redefined below
% with option nostruts.

\def\ttl@defnostruts{\def\nostruts{\let\ttl@strut\@empty}}

%               +-----------------+
%               |  O P T I O N S  |
%               +-----------------+

\DeclareOption{pagestyles}{\let\sectiontitle\@empty}
\DeclareOption{extramarks}{\let\ttl@fetchmark\@empty}
\DeclareOption{floatps}{%
  \ifx\sectiontitle\@empty
    \let\ttl@replace\space
  \else
    \PackageWarning{titlesec}{Ignoring `floatps' without 
      `pagestyles'. This option is now deprecated.}%
  \fi}
\DeclareOption{psfloats}{%
  \ifx\sectiontitle\@empty
    \let\ttl@replace\@empty
  \else
    \PackageWarning{titlesec}{Ignoring `psfloats' without 
      `pagestyles'}%
  \fi}

\DeclareOption{loadonly}{\let\ttl@extract\@empty}

\DeclareOption{outermarks}{%
  \def\ttl@titlemarks{\outertitlemarks}}
\DeclareOption{topmarks}{
  \def\ttl@titlemarks{\toptitlemarks}}
\DeclareOption{botmarks}{%
  \def\ttl@titlemarks{\bottitlemarks}}
\DeclareOption{innermarks}{%
  \def\ttl@titlemarks{\innertitlemarks}}

\DeclareOption{footmarks}{} % Backward compat

\DeclareOption{explicit}{\ttl@explicittrue}

\DeclareOption{clearempty}{%
  \def\cleardoublepage{%
    \clearpage{\ps@empty\if@twoside\ifodd\c@page\else
    \hbox{}\newpage\if@twocolumn\hbox{}\newpage\fi\fi\fi}}}

\DeclareOption{rigidchapters}{%
  \def\ttl@topmode#1#2{\vbox to #1{#2\vfil}}%
  \def\ttl@chapafter{.26\textheight}}
\DeclareOption{rubberchapters}{%
  \def\ttl@topmode#1#2{{#2}\ttl@calc\vspace{#1}}%
  \def\ttl@chapafter{40\p@}}

\DeclareOption{bottomtitles}{%
  \def\bottomtitlespace{-1\p@}}
\DeclareOption{nobottomtitles}{%
  \def\bottomtitlespace{.2\textheight}}
\DeclareOption{nobottomtitles*}{%
  \let\ttl@addstretch\relax
  \def\bottomtitlespace{.2\textheight}}

\DeclareOption{calcwidth}{%
  \let\ttl@beginlongest\ttl@xbeginlongest}

\DeclareOption{aftersep}{%
  \let\ttl@titlespace\@gobble}
\DeclareOption{largestsep}{%
  \let\ttl@titlespace\addvspace}

\DeclareOption{oldparttoc}{%
  \def\ttl@tocpart{\def\ttl@a{\thepart\hspace{1em}}}}
\DeclareOption{newparttoc}{%
  \let\ttl@tocpart\relax}
\DeclareOption{notocpart*}{%
  \let\ttl@notocparts\@empty}

\DeclareOption{rm}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\rmfamily}}
\DeclareOption{sf}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\sffamily}}
\DeclareOption{tt}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\ttfamily}}
\DeclareOption{md}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\mdseries}}
\DeclareOption{bf}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\bfseries}}
\DeclareOption{up}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\upshape}}
\DeclareOption{it}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\itshape}}
\DeclareOption{sl}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\slshape}}
\DeclareOption{sc}{%
  \protected@xdef\ttl@fonts{\ttl@fonts\protect\scshape}}

\DeclareOption{big}{%
  \gdef\ttl@sizes#1{\ifcase#1\relax\Huge\or\Large\or\large
       \or\normalsize\or\or\or\huge\fi}}
\DeclareOption{medium}{%
  \gdef\ttl@sizes#1{\ifcase#1\relax\huge\or\Large\or\large
       \or\normalsize\or\or\or\LARGE\fi}}
\DeclareOption{small}{%
  \gdef\ttl@sizes#1{\ifcase#1\relax\LARGE\or\large
       \or\normalsize\or\normalsize\or\or\or\Large\fi}}
\DeclareOption{tiny}{%
  \gdef\ttl@sizes#1{\ifcase#1\relax\large\or\normalsize\or
    \normalsize\or\normalsize\or\or\or\normalsize\fi}}

\DeclareOption{raggedleft}{%
  \gdef\ttl@fil{\filleft}}
\DeclareOption{center}{%
  \gdef\ttl@fil{\filcenter}}
\DeclareOption{raggedright}{%
  \gdef\ttl@fil{\filright}}

\DeclareOption{uppercase}{%
  \gdef\ttl@case{\MakeUppercase}}

\DeclareOption{compact}{%
  \gdef\ttl@space{1}%
  \gdef\ttl@chapafter{30\p@}}

% Deprecated. To be remmoved in a major upgrade (3.0)
\DeclareOption{indentfirst}{%
  \gdef\@afterindentfalse{\let\if@afterindent\iftrue}%
  \@afterindenttrue
  \def\titlespacing{%
    \@ifstar{\ttl@spacing@i{\@ne}}{\ttl@spacing@i{\@ne}}}}
\DeclareOption{nonindentfirst}{%
  \def\titlespacing{%
    \@ifstar{\ttl@spacing@i{\z@}}{\ttl@spacing@i{\z@}}}}

% New names
\DeclareOption{indentafter}{%
  \gdef\@afterindentfalse{\let\if@afterindent\iftrue}%
  \@afterindenttrue
  \def\titlespacing{%
    \@ifstar{\ttl@spacing@i{\@ne}}{\ttl@spacing@i{\@ne}}}}
\DeclareOption{noindentafter}{%
  \def\titlespacing{%
    \@ifstar{\ttl@spacing@i{\z@}}{\ttl@spacing@i{\z@}}}}

% newlinetospace
\let\ttl@blinemarks\relax
\let\ttl@elinemarks\relax

\DeclareRobustCommand\ttl@linetosp{%
  \@ifstar{\ttl@linetosp@i}{\ttl@linetosp@i}}%

\def\ttl@linetosp@i{%
  \ifdim\lastskip>\z@\else\space\fi
  \ignorespaces}

\DeclareOption{newlinetospace}{%
  \def\ttl@blinemarks{%
    \let\ttl@e\\%
    \def\\{\ttl@linetosp}}%
  \def\ttl@elinemarks{\let\\\ttl@e}}%

% toctitles
\def\ttl@addcontentsline#1#2{%
  \addcontentsline{toc}{#1}{\ifttl@toclabel\ttl@a\fi#2}%
  \nobreak}

\DeclareOption{toctitles}{%
  \def\ttl@addcontentsline#1#2{%
    \addcontentsline{toc}{#1}{\ifttl@toclabel\ttl@a\fi\ttl@savetitle}%
    \nobreak}}

% pageatnewline

\def\ttl@changecentercr{%
  \let\ttl@centercr\@centercr
  \def\@centercr{\@ifstar{\ttl@centercr*}{\ttl@centercr*}}}

\DeclareOption{pageatnewline}{\let\ttl@changecentercr\relax}

\def\ttl@fonts{}

% nostruts

\DeclareOption{nostruts}{%
  \let\ttl@strut\@empty
  \def\ttl@defnostruts{%
    \let\ttl@strut\@empty
    \def\nostruts{\let\ttl@strut\@empty}}}

\ExecuteOptions{rubberchapters,bottomtitles,aftersep,oldparttoc,%
  innermarks}

\ProcessOptions

%               +-----------------+
%               | H Y P E R R E F |
%               +-----------------+
%
% These two commands are provided by hyperref. But if they
% are not defined at \begin{document} hyperref has not been
% loaded or it is an old version.

\AtBeginDocument{%
  \ifx\ttl@Hy@steplink\@undefined
    \let\ttl@Hy@steplink\@gobble
    \let\ttl@Hy@refstepcounter\refstepcounter
  \fi}

%               +-----------------+
%               |   PAGE STYLES   |
%               +-----------------+
%
% This is generic:

\newcommand\assignpagestyle[2]{%
  \@namedef{ttl@ps@\expandafter\@gobble\string#1}{#2}}

% Old pagestyles
% ~~~~~~~~~~~~~~

\providecommand\newpagestyle{%
  \let\ttl@compatps\@empty % marks the ``old interface''
  \let\ttl@coreps\@empty
  \makeatletter
  \edef\ttl@d{%
    \noexpand\input{titleps.sty}%
    \catcode`\noexpand\@=\the\catcode`\@}%
  \ttl@d
  \newpagestyle}
  
\providecommand\renewpagestyle{%
  \let\ttl@compatps\@empty % marks the ``old interface''
  \let\ttl@coreps\@empty
  \makeatletter
  \edef\ttl@d{%
    \noexpand\input{titleps.sty}%
    \catcode`\noexpand\@=\the\catcode`\@}%
  \ttl@d
  \renewpagestyle}

\providecommand\widenhead{%
  \let\ttl@compatps\@empty % marks the ``old interface''
  \let\ttl@coreps\@empty
  \makeatletter
  \edef\ttl@d{%
    \noexpand\input{titleps.sty}%
    \catcode`\noexpand\@=\the\catcode`\@}%
  \ttl@d
  \widenhead}

% New pagestyles
% ~~~~~~~~~~~~~~

\@ifundefined{sectiontitle}{}{%
  \let\ttl@coreps\@empty
  \input{titleps.sty}}

%               +-----------------+
%               |     K E Y S     |
%               +-----------------+

\def\ttl@keys{%
  \let\ttl@keys\relax
  \@ifundefined{define@key}{\RequirePackage{keyval}}{}%
  \def\ttl@getkeys##1##2{%
    \let\ttl@a\@empty
    \if\expandafter @\@gobble##1@\@empty % if there is a single token
      \edef\ttl@b{\expandafter\@gobble\string##1}%
      \let\ttl@a\ttl@b
    \else
      \ttl@labelfalse  %  A temporary flag: true if there is page key
      \setkeys{##2}{##1}%
      \ifttl@label
        \@ifundefined{ttlp@\ttl@b}{%
          \expandafter\let\csname ttlp@\ttl@b\endcsname\@empty}{}%
      \fi
      \edef\ttl@a{\ttl@b\ttl@a}%
    \fi}%
  %
  \define@key{titlesec}{name}{%
    \edef\ttl@b{\expandafter\@gobble\string##1}}%
  \define@key{titlesec}{numberless}[true]{%
    \csname @tempswa##1\endcsname
    \if@tempswa
      \edef\ttl@a{\ttl@a/*}%
    \fi}%
  \define@key{titlesec}{page}{%
    \ttl@labeltrue  % Used as flag
    \edef\ttl@a{/##1\ttl@a}}%
  %
  \def\ttl@extra@numberless{\ttl@labeltrue}% The actual meaning
  \let\ttl@key@numberless\@empty
  %\let\ttl@key@matter\@empty
  \let\ttlp@append\@gobbletwo
  \def\ttl@setkeys##1{%
    \def\ttl@trylist{\ttl@try{}}%
    \@for\ttl@b:=##1\do{%
      \begingroup
        \let\ttl@a\relax
        \def\ttl@try####1{%
          \noexpand\ttl@try{####1\ttl@a{\ttl@b}}%
          \noexpand\ttl@try{####1}}%
        \xdef\ttl@trylist{\ttl@trylist}%
      \endgroup}}%
  \ttl@setkeys{page,numberless}% matter
  %
  \if@twoside
    \newcounter{ttlp@side}%
    \newcount\ttlp@side
    \def\ttlp@theside{\ifodd\c@page o\else e\fi}%
    \def\ttlp@append##1##2{%
     {\let\@elt\relax
      \expandafter\xdef\csname ttlp@##1\endcsname{%
         \csname ttlp@##1\endcsname\@elt ##2}}}%
    \def\ttlp@write##1{%
      {\let\ttlp@theside\relax
       \protected@write\@auxout{}%
         {\string\ttlp@append{##1}{\ttlp@theside}}}}%
    \def\ttlp@fetch##1{%
       \stepcounter{ttlp@side}%
       \global\advance\ttlp@side\@ne
       \@whilenum\ttlp@side<\c@ttlp@side\do{%
          \expandafter\@next\expandafter\@tempa\csname ttlp@##1\endcsname{}{}%
          \global\advance\ttlp@side\@ne}%
       \expandafter\@next\expandafter\ttl@b\csname ttlp@##1\endcsname{%
          \xdef\ttl@key@page{/\if\ttl@b oodd\else even\fi}%
       }{%
          \xdef\ttl@key@page{/\ifodd\c@page odd\else even\fi}%
       \@@warning{Unsynchronized `##1' title on page \thepage}}}%
  \else
    \let\ttlp@write\@gobble
    \def\ttlp@fetch##1{\gdef\ttl@key@page{/odd}}%
  \fi}

%               +-----------------+
%               |   C O M P A T   |
%               +-----------------+
% Easy setup, i.e., that of package options, is
% taken care of, if necessary.

\renewcommand\secdef[2]{%
  \@ifstar
    {\ttl@labelfalse
     #2}
    {\ttl@labeltrue
     \ifx#1\@chapter
       \if@mainmatter\else\ttl@labelfalse\fi
       \ifnum\ttll@chapter>\c@secnumdepth\ttl@labelfalse\fi
     \else\ifx#1\@part
       \ifnum\ttll@part>\c@secnumdepth\ttl@labelfalse\fi
     \fi\fi
     \let\ifttl@toclabel\ifttl@label
     \@dblarg{#1}}}

\@ifundefined{ttl@extract}{}{\endinput}

\newcommand\titlelabel[1]{%
  \def\@seccntformat##1{#1}}

\@ifundefined{chapter}%
  {\def\ttl@compatpart{\titleclass{\part}{part}\relax}}%
  {\def\ttl@compatchapter{%
     \def\@makechapterhead{%
       \ttl@labeltrue
       \if@mainmatter\else\ttl@labelfalse\fi
       \ifnum\ttll@chapter>\c@secnumdepth\ttl@labelfalse\fi
       \ttl@startargs\ttl@mkchap{chapter}}%
     \def\@makeschapterhead{%
       \ttl@labelfalse
       \if@mainmatter\else\ttl@labelfalse\fi
       \ifnum\ttll@chapter>\c@secnumdepth\ttl@labelfalse\fi
       \ttl@startargs\ttl@mkchap{chapter}}}%
   \def\ttl@compatpart{\titleclass{\part}{page}\relax}}
   
\def\ttl@@extract#1\@startsection#2#3#4#5#6#7#8{%
  \@tempskipa=#5
  \@tempskipb=#6
  \ifdim\@tempskipa<\z@
    \toks@{\titlespacing*#8{#4}}%
    \@tempskipa-\@tempskipa
  \else
    \toks@{\titlespacing#8{#4}}%
  \fi
  \@ifundefined{ttl@space}{}{%
    \ttl@assign\@tempskipa*\ttl@space\relax\beforetitleunit}%
  \ifdim\@tempskipb<\z@
    \if@tempswa
      \titleformat#8[runin]%
         {\ttl@fonts\ttl@sizes{#3}}{\@seccntformat{#2}}%
         {\z@}\ttl@passexplicit
    \else
      \titleformat#8[runin]%
         {#7}{\@seccntformat{#2}}%
         {\z@}\ttl@passexplicit
    \fi
    \@tempskipb-\@tempskipb
  \else
    \if@tempswa
      \titleformat#8%
        {\ttl@fil\ttl@fonts\ttl@sizes{#3}}{\@seccntformat{#2}}%
        {\z@}\ttl@passexplicit 
    \else
      \titleformat#8%
        {#7}{\@seccntformat{#2}}%
        {\z@}\ttl@passexplicit
    \fi
    \@ifundefined{ttl@space}{}{%
      \ttl@assign\@tempskipb*\ttl@space\relax\aftertitleunit}%
  \fi
  \edef\ttl@a{\the\toks@{\the\@tempskipa}{\the\@tempskipb}}
  \ttl@a}

\def\ttl@extract#1{%
  \ifx#1\@undefined
    \let#1\relax % Avoid error if undefined
  \fi
  \expandafter\in@\expandafter\@startsection\expandafter{#1}%
  \ifin@
    \expandafter\ttl@@extract#1#1%
  \else
    \PackageWarningNoLine{titlesec}%
      {Non standard sectioning command \string#1\MessageBreak
       detected. Using default spacing and no format}%
    \titlespacing*#1{\z@}{*3}{*2}%
  \fi}

\@tempswafalse

\ifx\ttl@fonts\@empty
  \def\ttl@fonts{\bfseries}
\else
  \@tempswatrue
\fi

\expandafter\ifx\csname ttl@sizes\endcsname\relax
  \gdef\ttl@sizes#1{\ifcase#1\relax\Huge\or\Large\or\large
       \or\normalsize\or\or\or\huge\fi}
\else
  \@tempswatrue
\fi

\expandafter\ifx\csname ttl@fil\endcsname\relax
  \let\ttl@fil\@empty
\else
  \@tempswatrue
\fi

\expandafter\ifx\csname ttl@case\endcsname\relax
  \let\ttl@case\@firstofone
\else
  \@tempswatrue
\fi

\if@tempswa

  \@ifundefined{chapter}{}%
    {\titleformat\chapter[display]%
      {\@ifundefined{ttl@fil}{\raggedright}{\ttl@fil}\ttl@fonts\ttl@sizes6}%
      {\@chapapp\space\thechapter}%
      {.8\baselineskip}%
      {\ttl@sizes\z@\ttl@passexplicit}}

\fi

\ttl@extract\section
\ttl@extract\subsection
\ttl@extract\subsubsection
\ttl@extract\paragraph
\ttl@extract\subparagraph

\let\ttl@extract\@undefined
\let\ttl@@extract\@undefined

\def\ttl@toplevel{part}

\@ifundefined{chapter}%
  {\@namedef{ttll@part}{0}%
   \titleclass{\section}{straight}[\part]%
   \titlespacing*{\part}%
     {\z@}%
     {4ex}%
     {3ex}}%
  {\let\ttl@save@mkchap\@makechapterhead
   \let\ttl@save@mkschap\@makeschapterhead
   %
   \def\@makechapterhead#1{%
     \gdef\ttl@savemark{\chaptermark{#1}}%
     \ttl@save@mkchap{#1}%
     \@ifundefined{ttl@ps@chapter}{}%
       {\thispagestyle{\@nameuse{ttl@ps@chapter}}}}%
   %
   \def\@makeschapterhead#1{%
     \gdef\ttl@savemark{\chaptermark{#1}}%
     \ttl@save@mkschap{#1}%
     \@ifundefined{ttl@ps@chapter}{}%
       {\thispagestyle{\@nameuse{ttl@ps@chapter}}}}%
   %
   \@namedef{ttll@part}{-1}%
   \@namedef{ttlss@part}{chapter}%
   \@namedef{ttll@chapter}{0}%
   \titleclass{\section}{straight}[\chapter]%
% The following is unoperant, unless when \chapter / \part
% format is redefined
   \titlespacing*{\part}%
     {\z@}%
     {\z@\@plus1fil}%
     {\z@\@plus1fil}% 
   \titlespacing*\chapter
     {\z@}%
     {50\p@}%
     {\ttl@chapafter}}

\titleclass{\subsection}   {straight}[\section]
\titleclass{\subsubsection}{straight}[\subsection]
\titleclass{\paragraph}    {straight}[\subsubsection]
\titleclass{\subparagraph} {straight}[\paragraph]

\endinput

MIT License
-----------

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.