% \CheckSum{2469}
% \iffalse^^A meta-comment
% ======================================================================
% scrlayer-scrpage.dtx
% Copyright (c) Markus Kohm, 2012-2016
%
% This file is part of the LaTeX2e KOMA-Script bundle.
%
% This work may be distributed and/or modified under the conditions of
% the LaTeX Project Public License, version 1.3c of the license.
% 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 2005/12/01 and of this work.
%
% This work has the LPPL maintenance status "author-maintained".
%
% The Current Maintainer and author of this work is Markus Kohm.
%
% Dieses Werk besteht aus den in manifest.txt aufgefuehrten Dateien.
% ----------------------------------------------------------------------
% scrlayer-scrpage.dtx
% Copyright (c) Markus Kohm, 2012-2016
%
% Diese Datei ist Teil der LaTeX2e KOMA-Script-Sammlung.
%
% Dieses Werk darf nach den Bedingungen der LaTeX Project Public Lizenz,
% Version 1.3c.
% Die neuste Version dieser Lizenz ist
%   http://www.latex-project.org/lppl.txt
% und Version 1.3c ist Teil aller Verteilungen von LaTeX
% Version 2005/12/01 und dieses Werks.
%
% Dieses Werk hat den LPPL-Verwaltungs-Status "author-maintained"
% (allein durch den Autor verwaltet).
%
% Der Aktuelle Verwalter und Autor dieses Werkes ist Markus Kohm.
%
% Dieses Werk besteht aus den in manifest.txt aufgefuehrten Dateien.
% ======================================================================
% \fi^^A meta-comment
%
% \CharacterTable
%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%   Digits        \0\1\2\3\4\5\6\7\8\9
%   Exclamation   \!     Double quote  \"     Hash (number) \#
%   Dollar        \$     Percent       \%     Ampersand     \&
%   Acute accent  \'     Left paren    \(     Right paren   \)
%   Asterisk      \*     Plus          \+     Comma         \,
%   Minus         \-     Point         \.     Solidus       \/
%   Colon         \:     Semicolon     \;     Less than     \<
%   Equals        \=     Greater than  \>     Question mark \?
%   Commercial at \@     Left bracket  \[     Backslash     \\
%   Right bracket \]     Circumflex    \^     Underscore    \_
%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%   Right brace   \}     Tilde         \~}
%
% \iffalse^^A meta-comment
%<identify>%%% From File: $Id: scrlayer-scrpage.dtx 2429 2016-04-12 12:10:19Z kohm $ (identify)
%<init>%%% From File: $Id: scrlayer-scrpage.dtx 2429 2016-04-12 12:10:19Z kohm $ (init)
%<options>%%% From File: $Id: scrlayer-scrpage.dtx 2429 2016-04-12 12:10:19Z kohm $ (options)
%<body>%%% From File: $Id: scrlayer-scrpage.dtx 2429 2016-04-12 12:10:19Z kohm $ (body)
%<*dtx>
\ifx\ProvidesFile\undefined\def\ProvidesFile#1[#2]{}\fi
\begingroup
  \def\filedate$#1: #2-#3-#4 #5${\gdef\filedate{#2/#3/#4}}
  \filedate$Date: 2016-04-12 14:10:19 +0200 (Tue, 12 Apr 2016) $
  \def\filerevision$#1: #2 ${\gdef\filerevision{#2}}
  \filerevision$Revision: 2429 $
\endgroup
\ProvidesFile{scrlayer-scrpage.dtx}[\filedate\space r\filerevision\space
%</dtx>
%<*identify>
%<interface>\NeedsTeXFormat{LaTeX2e}[1995/12/01]
%<interface>\ProvidesPackage{scrlayer-scrpage}[%
%!KOMAScriptVersion
%<interface>  package
%</identify>
%<*dtx|identify>
  (end user interface for scrlayer)]
%</dtx|identify>
%<*dtx>
\ifx\documentclass\undefined
  \input scrdocstrip.tex
  \@@input scrkernel-version.dtx
  \@@input scrstrip.inc
  \KOMAdefVariable{COPYRIGHTFROM}{2012}
  \generate{\usepreamble\defaultpreamble
    \file{scrlayer-scrpage.sty}{%
      \from{scrlayer-scrpage.dtx}{interface,trace,scrpage,identify}%
      \from{scrlayer.dtx}{interface,trace,scrpage,init}%
      \from{scrlayer-scrpage.dtx}{interface,trace,scrpage,init}%
      \from{scrlayer.dtx}{interface,trace,scrpage,options}%
      \from{scrlayer-scrpage.dtx}{interface,trace,scrpage,options}%
      \from{scrlayer.dtx}{interface,trace,scrpage,body}%
      \from{scrlayer-scrpage.dtx}{interface,trace,scrpage,body}%
      \from{scrlogo.dtx}{logo}%
    }%
  }
  \@@input scrstrop.inc
\else
  \let\endbatchfile\relax
\fi
\endbatchfile
%</dtx>
%<*driver>
  \documentclass{scrdoc}
  \addtolength{\textwidth}{-1em}
  \addtolength{\marginparwidth}{2em}
  \addtolength{\oddsidemargin}{2em}
  \usepackage[ngerman,english]{babel}
  \usepackage{url,babelbib}\bibliographystyle{babalpha-fl}
  \usepackage{listings}
  \usepackage{scrhack}
  \usepackage{etoolbox}
  \pretocmd\DescribeMacro{\ifhmode\else\bigskip\noindent\fi}{}{}
  \pretocmd\DescribeEnv{\ifhmode\else\bigskip\noindent\fi}{}{}
  \pretocmd\DescribeOption{\ifhmode\else\bigskip\noindent\fi}{}{}

  \CodelineIndex
  \RecordChanges
  \GetFileInfo{scrlayer-scrpage.dtx}
  \title{The \texttt{scrlayer} interface \texttt{scrlayer-scrpage}%
    \footnote{This is version \fileversion\ of file \texttt{\filename}.}}
  \date{\filedate}
  \author{Markus Kohm}

  \newenvironment{Explain}{\par}{\par}
  \newcommand*{\length}{}
  \let\length\Length
  \let\endlength\endLength
  \let\Macro\cs
  \let\Length\Macro
  \let\Package\textsf
  \let\Class\Package
  \let\File\texttt
  \let\Option\texttt
  \newcommand*{\KOption}[1]{\Option{#1}\texttt{=}}
  \newcommand*{\OptionValue}[2]{\Option{#1}\texttt{=}\PValue{#2}}
  \let\Counter\texttt
  \let\Environment\texttt
  \let\ShowOutput\quote
  \let\endShowOutput\endquote
  \let\Pagestyle\texttt
  \newcommand*{\Parameter}[1]{\texttt{\marg{#1}}\linebreak[1]}
  \newcommand*{\OParameter}[1]{\texttt{\oarg{#1}}\linebreak[1]}
  \newcommand*{\MParameter}[2]{\texttt{(\meta{#1},\meta{#2})}\linebreak[1]}
  \providecommand\PParameter[1]{\mbox{\texttt{\{#1\}}}\linebreak[1]}
  \let\PName\meta
  \let\PValue\texttt
  \providecommand*{\autoref}[1]{\expandafter\AUTOREF#1:}
  \providecommand*{\AUTOREF}{}
  \makeatletter
  \def\AUTOREF#1:#2:{%
    \edef\@tempa{#1}%
    \edef\@tempb{tab}\ifx\@tempa\@tempb table~\fi
    \edef\@tempb{sec}\ifx\@tempa\@tempb section~\fi
    \ref{#1:#2}%
  }
  \providecommand*{\IndexCmd}[2][]{}
  \providecommand*{\textnote}[2][]{}
  \providecommand*\eTeX{\leavevmode\hbox{$\varepsilon$}-\TeX}
  \providecommand*\NTS{%
    \leavevmode\hbox{$\cal N\kern-0.35em\lower0.5ex\hbox{$\cal T$}%
      \kern-0.2emS$}}

  \lstnewenvironment{lstcode}{\lstset{language=[LaTeX]TeX}}{}
  \makeatother
  \sloppy% YOU SHOULD NOT DO THIS!!!

  \begin{document}
  \maketitle
  \tableofcontents
  \DocInput{\filename}
  \PrintChanges
  \PrintIndex
  \end{document}
%</driver>
%<*dtx>
% \fi^^A meta-comment
%
% \selectlanguage{english}
%
% \changes{v0.0}{2012/01/01}{start of interface}
% \let\restorechapter\chapter
% \let\chapter\section
% \let\section\subsection
% \let\subsection\subsubsection
%
%\iffalse
%</dtx>
%\fi
%
% \StopEventually{}
%
% \chapter{Implementation of \Package{scrlayer-scrpage}}
% \label{sec:scrlayer-scrpage}
%
% This section if for developers only.
%
% \iffalse
%<*interface>
%<*identify>
% \fi
%
%\iffalse
%</identify>
%\fi
%
%
% \section{Initialising some Values before the Options}
%
% \iffalse^^A meta-comment
%<*init>
% \fi^^A meta-comment
%
% Initialisation before all options (even the options from
% \File{scrlayer.dtx}).
%
% Currently nothing.
%
% \iffalse^^A meta-comment
%</init>
% \fi^^A meta-comment
%
% \section{Options}
%
% \iffalse^^A meta-comment
%<*options>
% \fi
%
% Package \Package{scrpage2} doesn't support \KOMAScript{} options but only
% regular \LaTeX{} package options.  The interface will also support those
% options, but uses \KOMAScript{} options for the implementation.  This
% results in additional features of the interface.
%
% Note, that some options are already defined before this by the common option
% parts of \File{scrlayer.dtx}. All others will follow step by step in the
% main part.
%
% Options \Option{headinclude}, \Option{headexclude}, \Option{footinclude} and
% \Option{footexclude} of package \Package{scrpage2} are deprecated since
% package version 2.3, 2008-12-08. They won't be supported by the
% \Package{scrlayer-scrpage} interface.
%
% Additional initialisation may be done here, but currently this isn't
% needed.
%
% \iffalse^^A meta-comment
%</options>
% \fi^^A meta-comment
%
%
% \section{Width of Header and Footer}
%
% \Package{scrpage2} provides to set the width of the page head or footer
% different from the width of the text area of the page using
% \Macro{setheadwidth} and \Macro{setfootwidth}. Optionally those commands
% allow to setup an horizontal offset for the head or footer. This interface
% provides the same feature but also allows to set up the widths and offsets
% with \KOMAScript{} options. Those options will become the primary interface.
%
% \begin{option}{headwidth}
%   \changes{v0.9.1757}{2014/04/09}{new: two offsets available}^^A
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{option}{footwidth}
%   \changes{v0.9.1757}{2014/04/09}{new: two offsets available}^^A
%   \changes{v3.15}{2014/12/28}{fix: missing colon in call of
%     \cs{sls@split@at@iicolons}}^^A
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
%   \begin{description}
%   \item[\texttt{=\meta{special dimensional expression}:\meta{special
%     dimensional expression}}:] see \Macro{sls@settowidthof} for information
%     about the syntax of \meta{special dimensional expression}. The width of
%     the page head or footer will be set to the result of the first on, the
%     offset to the result of the second one. If the first one\,---\,the
%     width\,---\,is omitted, the current width will be used. If the second
%     one\,---\,the offset\,---\,is omitted and the width is the width of the
%     text area plus the margin note column, the offset will be set to
%     zero. If the second one is omitted and the width is not the width of the
%     text area plus the margin note column, a special kind of centering will
%     be used.
%   \end{description}
% These options may be used to set up the widths of head and foot.
%    \begin{macrocode}
%<*options>
\KOMA@key{headwidth}{%
  \begingroup
    \sls@split@at@iicolons#1:::\@nil
    \ifx\reserved@a\@empty \let\reserved@a\sls@headwidth\fi
    \edef\reserved@a{%
      \noexpand\endgroup
      \noexpand\sls@set@hf@width{head}{\reserved@b}{\reserved@c}{\reserved@a}%
      \noexpand\FamilyKeyStateProcessed
      \noexpand\KOMA@kav@replacevalue{.scrlayer-scrpage.sty}{headwidth}{%
        \reserved@a:\reserved@b:\reserved@c
      }%
    }%
  \reserved@a
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@headwidth}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@headwidth@default}
\KOMA@key{footwidth}{%
  \begingroup
    \sls@split@at@iicolons#1:::\@nil
    \ifx\reserved@a\@empty \let\reserved@a\sls@footwidth\fi
    \edef\reserved@a{%
      \noexpand\endgroup
      \noexpand\sls@set@hf@width{foot}{\reserved@b}{\reserved@c}{\reserved@a}%
      \noexpand\FamilyKeyStateProcessed
      \noexpand\KOMA@kav@replacevalue{.scrlayer-scrpage.sty}{footwidth}{%
        \reserved@a:\reserved@b:\reserved@c
      }%
    }%
  \reserved@a
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@footwidth}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@footwidth@default}
%    \end{macrocode}
% \begin{macro}{\sls@split@at@iicolons}
%   \begin{description}
%   \item[\texttt{\meta{balanced}:^^A
%     \meta{balanced}:^^A
%     \meta{balanced}\Macro{@nil}}:] first \meta{balanced} will be stored into
%     \Macro{reserved@a}, second into \Macro{reserved@b}, third will be eaten
%     and warn about if it is neither empty and nor a colon.
%   \end{description}
% This little helper is used, e.g., by options \Option{headwidth} and
% \Option{footwidth}.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@split@at@iicolons{%
  \def\sls@split@at@iicolons#1:#2:#3:#4\@nil{%
    \ifstr{#4}{}{}{%
      \ifstr{#4}{:}{}{%
        \ifstr{#4}{::}{}{%
          \PackageWarning{scrlayer}{extra `:' found!\MessageBreak
            You've used more than two colons at the argument\MessageBreak
            of a two value option.\MessageBreak
            The extra value(s) will be ignored%
          }%
        }%
      }%
    }%
    \def\reserved@a{#1}%
    \def\reserved@b{#2}%
    \def\reserved@c{#3}%
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@split@at@iicolons
% \begin{macro}{\sls@set@hf@width}
%   \changes{v0.9.1757}{2014/04/09}{new: two offsets available}
%   \begin{description}
%   \item[\Parameter{head} or \Parameter{foot}:] to complete the macro names
%     for page head or footer.
%   \item[\Parameter{special dimensional expression}:] the offset odd page
%   \item[\Parameter{special dimensional expression}:] the offset even page
%   \item[\Parameter{special dimensional expression}:] the width
%   \end{description}
% This helper will generally set up width an offset of either head or footer.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@set@hf@width{%
  \newcommand*{\sls@set@hf@width}[4]{%
    \sls@settowidthof{\@tempdima}{#4}%
    \ifdim\@tempdima>\paperwidth
      \PackageWarning
        {scrlayer-scrpage}%
        {You've set width of #1 to a value\MessageBreak
          greater than width of page!\MessageBreak%
          I'll reduce width of #1 to width of page}%
      \setlength{\@tempdima}{\paperwidth}%
    \else
      \ifdim\@tempdima<\z@
         \PackageWarning
           {scrlayer-scrpage}%
           {You've set width of #1 to negative value!\MessageBreak%
             I'll set it to 0pt}%
         \setlength{\@tempdima}{\z@}%
       \fi
    \fi
    \expandafter\edef\csname sls@#1width\endcsname{\the\@tempdima}%
    \setlength{\@tempdima}{\textwidth}%
    \addtolength{\@tempdima}{-\csname sls@#1width\endcsname}%
    \ifstr{#2}{}{%
      \ifdim \csname sls@#1width\endcsname
           = \dimexpr \textwidth+\marginparwidth+\marginparsep\relax
        \setlength{\@tempdimb}{\z@}
      \else
        \if@twoside
          \setlength{\@tempdimb}{.3333333333\@tempdima}%
        \else
          \setlength{\@tempdimb}{.5\@tempdima}%
        \fi
      \fi
    }{%
      \sls@settowidthof{\@tempdimb}{#2}%
    }%
    \ifstr{#3}{}{%
      \addtolength{\@tempdima}{-\@tempdimb}%
    }{%
      \sls@settowidthof{\@tempdima}{#3}%
      \setlength{\@tempdima}{-\@tempdima}%
    }%
    \ifdim\@tempdimb<\z@
      \setlength{\@tempdimb}{-\@tempdimb}%
      \expandafter\edef\csname sls@odd#1shift\endcsname{-\the\@tempdimb}%
    \else
      \expandafter\edef\csname sls@odd#1shift\endcsname{\the\@tempdimb}%
    \fi
    \ifdim\@tempdima<\z@
      \setlength{\@tempdima}{-\@tempdima}%
      \expandafter\edef\csname sls@even#1shift\endcsname{-\the\@tempdima}%
    \else
      \expandafter\edef\csname sls@even#1shift\endcsname{\the\@tempdima}%
    \fi
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@set@hf@width
% \begin{macro}{\sls@headwidth}
% \begin{macro}{\sls@oddheadshift}
% \begin{macro}{\sls@evenheadshift}
% \begin{macro}{\sls@footwidth}
% \begin{macro}{\sls@oddfootshift}
% \begin{macro}{\sls@evenfootshift}
% To store width and offset of page head an footer, we use macros. Those are
% also used by the options and therefore need to be initialised before option
% usage.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@headwidth{%
  \scr@ifundefinedorrelax{@headwidth}{%
    \newcommand*{\sls@headwidth}{\textwidth}%
    \KOMA@kav@add{.scrlayer-scrpage.sty}{headwidth}{\textwidth:0pt:0pt}%
  }{%
    \newcommand*{\sls@headwidth}{\@headwidth}%
    \KOMA@kav@xadd{.scrlayer-scrpage.sty}{headwidth}{\@headwidth:0pt:0pt}%
  }%
}
\scrlayerAddToInterface\sls@oddheadshift{\newcommand*{\sls@oddheadshift}{0pt}}
\scrlayerAddToInterface\sls@evenheadshift{\newcommand*{\sls@evenheadshift}{0pt}}
\scrlayerAddToInterface\sls@footwidth{%
  \scr@ifundefinedorrelax{@footwidth}{%
    \newcommand*{\sls@footwidth}{\textwidth}%
    \KOMA@kav@add{.scrlayer-scrpage.sty}{footwidth}{\textwidth:0pt:0pt}
  }{%
    \newcommand*{\sls@footwidth}{\@footwidth}%
    \KOMA@kav@xadd{.scrlayer-scrpage.sty}{footwidth}{\@footwidth:0pt:0pt}
  }%
}
\scrlayerAddToInterface\sls@oddfootshift{\newcommand*{\sls@oddfootshift}{0pt}}
\scrlayerAddToInterface\sls@evenfootshift{\newcommand*{\sls@evenfootshift}{0pt}}
%    \end{macrocode}
% \end{macro}^^A \sls@headwidth
% \end{macro}^^A \sls@oddheadshift
% \end{macro}^^A \sls@evenheadshift
% \end{macro}^^A \sls@footwidth
% \end{macro}^^A \sls@oddfootshift
% \end{macro}^^A \sls@evenfootshift
%
% \begin{macro}{\sls@settowidthof}
% \begin{macro}{\sls@deftowidthof}
% the special dimensional expressions may be either one of the strings
% \texttt{paper}, \texttt{text}, \texttt{marginpar},
% \texttt{textwithmarginpar}, \texttt{head}, \texttt{foot},
% \texttt{headtopline}, \texttt{headsepline}, \texttt{footsepline},
% \texttt{footbotline}, or \texttt{page} or a valid dimensional
% expression. But it cannot be both a dimensional expression using symbolic
% values!
%    \begin{macrocode}
\scrlayerAddToInterface\sls@settotwidthof{%
  \newcommand*{\sls@settowidthof}[2]{%
    \ifstr{#2}{paper}{%
      \setlength{#1}{\paperwidth}%
    }{%
      \ifstr{#2}{text}{%
        \setlength{#1}{\textwidth}%
      }{%
        \ifstr{#2}{marginpar}{%
          \setlength{#1}{\dimexpr \marginparwidth+\marginparsep\relax}%
        }{%
          \ifstr{#2}{textwithmarginpar}{%
            \setlength{#1}{\dimexpr\textwidth
                                  +\marginparwidth
                                  +\marginparsep\relax}%
          }{%
            \ifstr{#2}{head}{%
              \setlength{#1}{\sls@headwidth}%
            }{%
              \ifstr{#2}{foot}{%
                \setlength{#1}{\sls@footwidth}%
              }{%
                \ifstr{#2}{headtopline}{%
                  \setlength{#1}{\sls@headabove@linelength}%
                }{%
                  \ifstr{#2}{headsepline}{%
                    \setlength{#1}{\sls@headbelow@linelength}%
                  }{%
                    \ifstr{#2}{footsepline}{%
                      \setlength{#1}{\sls@footabove@linelength}%
                    }{%
                      \ifstr{#2}{footbotline}{%
                        \setlength{#1}{\sls@footbelow@linelength}%
                      }{%
                        \ifstr{#2}{page}{%
                          \setlength{#1}{\paperwidth}%
                          \begingroup
                          \expandafter\expandafter\expandafter\endgroup
                          \expandafter\ifx\csname ta@bcor\endcsname\relax\else
                            \addtolength{#1}{-\ta@bcor}%
                          \fi
                        }{%
                          \setlength{#1}{\dimexpr #2\relax}%
                        }%
                      }%
                    }%
                  }%
                }%
              }%
            }%
          }%
        }%
      }%
    }%
  }%
}
\scrlayerAddToInterface\sls@deftowidthof{%
  \newcommand*{\sls@deftowidthof}[2]{%
    \ifstr{#2}{autohead}{%
      \expandafter\def\csname #1\endcsname{\sls@headwidth}%
    }{%
      \ifstr{#2}{autofoot}{%
        \expandafter\def\csname #1\endcsname{\sls@footwidth}%
      }{%
        \sls@settowidthof{\@tempdima}{#2}%
        \expandafter\edef\csname #1\endcsname{\the\@tempdima}%
      }%
    }%
  }%
}
%</options>
%    \end{macrocode}
% \end{macro}^^A \sls@deftowidthof
% \end{macro}^^A \sls@settowidthof
% \end{option}^^A footwidth
% \end{option}^^A footheight
%
% \begin{macro}{\setheadwidth}
% \begin{macro}{\setfootwidth}
% For compatibility with \Package{scrpage2}, map the commands to the options:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\setheadwidth{%
  \newcommand*{\setheadwidth}[2][]{%
    \KOMAoptions{headwidth=#2:#1}%
  }%
}
\scrlayerAddToInterface\setfootwidth{%
  \newcommand*{\setfootwidth}[2][]{%
    \KOMAoptions{footwidth=#2:#1}%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \setheadwidth
% \end{macro}^^A \setfootwidth
%
%
% \section{Lines in Page Head and Footer}
%
% The interface implements the options \Option{headtopline},
% \Option{headsepline}, \Option{footsepline}, \Option{footbotline},
% \Option{plainheadtopline}, \Option{plainheadsepline},
% \Option{plainfootsepline}, \Option{plainfootbotline}, \Option{ilines},
% \Option{clines}, and \Option{olines}, the commands \Macro{setheadtopline},
% \Macro{setheadsepline}, \Macro{setfootsepline}, and \Macro{setfootbotline},
% and the corresponding \KOMAScript{} font elements of package
% \Package{scrpage2}. Some of the options are extended to understand
% values.
%
% \begin{option}{headtopline}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{option}{headsepline}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{option}{footsepline}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{option}{footbotline}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{description}
% \item[{\texttt{=\meta{dimensional expression}:\meta{dimensional
%   expression}}:}]
% \end{description}\noindent
% Define thickness and length of the a default separation line between:
% \begin{description}
% \item[\Option{headtopline}:] the top margin of the page and the page head.
% \item[\Option{headsepline}:] the page head and the text area.
% \item[\Option{footsepline}:] the text area and the page footer.
% \item[\Option{footbotline}:] the page footer and the bottom margin.
% \end{description}
% Both values may be omitted. In that case thickness would be 0.4\,pt, and
% length would be the width of the page head or footer.  If the second
% argument, the length, has been omitted the \texttt{:} may also be omitted.
%    \begin{macrocode}
%<*options>
\KOMA@key{headtopline}[:]{%
  \sls@set@values[headtopline]{head}{above}{#1}%
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@headtopline}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@headtopline@default}
\KOMA@key{headsepline}[:]{%
  \sls@set@values[headsepline]{head}{below}{#1}%
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@headsepline}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@headsepline@default}
\KOMA@key{footsepline}[:]{%
  \sls@set@values[footsepline]{foot}{above}{#1}%
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@footsepline}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@footsepline@default}
\KOMA@key{footbotline}[:]{%
  \sls@set@values[footbotline]{foot}{below}{#1}%
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@footbotline}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@footbotline@default}
%    \end{macrocode}
% \begin{macro}{\sls@set@values}
%   \begin{description}
%   \item[\OParameter{option name}:] either empty or the name of the option
%     that sets the line,
%   \item[\Parameter{head or foot}:] either \texttt{head} or \texttt{foot},
%   \item[\Parameter{above or below}:] either \texttt{above} or
%     \texttt{below},
%   \item[\Parameter{dimension expression}\texttt{:}\Parameter{dimension
%     expression}] length an thickness of a line (both are optional).
%   \end{description}
% Helper macros for the options to set two macros by two values of one
% option. The two values are separated by a colon.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@set@values{%
  \newcommand*{\sls@set@values}[4][]{%
    \begingroup
      \ifstr{#1}{}{%
        \FamilyKeyStateUnknown
      }{%
        \KOMA@set@ifkey{#1}{@tempswa}{#4}%
      }%
      \ifx\FamilyKeyState\FamilyKeyStateProcessed
        \if@tempswa
          \edef\reserved@b{%
            \noexpand\endgroup
            \noexpand\@namedef{sls@#2#3@linethickness}{.4pt}%
            \noexpand\@namedef{sls@#2#3@linelength}{%
              \expandafter\noexpand\csname sls@#2width\endcsname
            }%
          }%
        \else
          \def\reserved@b{%
            \endgroup
            \@namedef{sls@#2#3@linethickness}{0pt}%
            \@namedef{sls@#2#3@linelength}{0pt}%
          }%
        \fi
      \else
        \let\reserved@a\@empty
        \let\reserved@b\@empty
        \sls@split@at@colon#4::\@nil
        \ifx\reserved@a\@empty
          \def\reserved@a{\endgroup\@namedef{sls@#2#3@linethickness}{.4pt}}%
        \else
          \setlength{\@tempdima}{\dimexpr\reserved@a\relax}%
          \edef\reserved@a{%
            \noexpand\endgroup
            \noexpand\@namedef{sls@#2#3@linethickness}{\the\@tempdima}%
          }%
        \fi
        \ifx\reserved@b\@empty
          \def\reserved@b{%
            \reserved@a
            \@namedef{sls@#2#3@linelength}{\@nameuse{sls@#2width}}%
          }%
        \else
          \edef\reserved@b{%
            \noexpand\reserved@a
            \noexpand\sls@deftowidthof{sls@#2#3@linelength}{\reserved@b}%
          }%
        \fi
      \fi
    \reserved@b
    \FamilyKeyStateProcessed
    \ifstr{#1}{}{}{%
      \KOMA@kav@xreplacevalue{.scrlayer-scrpage.sty}{#1}{%
        \csname sls@#2#3@linethickness\endcsname
        :\csname sls@#2#3@linelength\endcsname
      }%
    }%
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@set@values
% \begin{macro}{\sls@split@at@colon}
%   \begin{description}
%   \item[\texttt{\meta{balanced}:^^A
%     \meta{balanced}:^^A
%     \meta{balanced}\Macro{@nil}}:] first \meta{balanced} will be stored into
%     \Macro{reserved@a}, second into \Macro{reserved@b}, third will be eaten
%     and warn about if it is neither empty and nor a colon.
%   \end{description}
% This little helper is used, e.g., by options \Option{headwidth} and
% \Option{footwidth}.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@split@at@colon{%
  \def\sls@split@at@colon#1:#2:#3\@nil{%
    \ifstr{#3}{}{}{%
      \ifstr{#3}{:}{}{%
        \PackageWarning{scrlayer}{extra `:' found!\MessageBreak
          You've used more than one colon at the argument\MessageBreak
          of a two value option.\MessageBreak
          The extra value(s) will be ignored%
        }%
      }%
    }%
    \def\reserved@a{#1}%
    \def\reserved@b{#2}%
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@split@at@colon
% \begin{macro}{\sls@headabove@linelength}
% \begin{macro}{\sls@headabove@linethickness}
% \begin{macro}{\sls@headbelow@linelength}
% \begin{macro}{\sls@headbelow@linethickness}
% \begin{macro}{\sls@footabove@linelength}
% \begin{macro}{\sls@footabove@linethickness}
% \begin{macro}{\sls@footbelow@linelength}
% \begin{macro}{\sls@footbelow@linethickness}
% To store length and thickness of the lines at the page head an footer, we
% use macros. Those are also used by the options and therefore need to be
% initialised before option usage.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@headabove@linelength{%
  \newcommand*{\sls@headabove@linelength}{\sls@headwidth}%
}
\scrlayerAddToInterface\sls@headabove{%
  \newcommand*{\sls@headabove@linethickness}{0pt}%
}
\KOMA@kav@xadd{.scrlayer-scrpage.sty}{headtopline}{%
  \expandafter\noexpand\sls@headabove@linethickness:%
  \expandafter\noexpand\sls@headabove@linelength}
\scrlayerAddToInterface\sls@headbelow@linelength{%
  \newcommand*{\sls@headbelow@linelength}{\sls@headwidth}%
}
\scrlayerAddToInterface\sls@headbelow@linethickness{%
  \newcommand*{\sls@headbelow@linethickness}{0pt}%
}
\KOMA@kav@xadd{.scrlayer-scrpage.sty}{headsepline}{%
  \expandafter\noexpand\sls@headbelow@linethickness:%
  \expandafter\noexpand\sls@headbelow@linelength}
\scrlayerAddToInterface\sls@footabove@linelength{%
  \newcommand*{\sls@footabove@linelength}{\sls@footwidth}%
}
\scrlayerAddToInterface\sls@footabove@linethickness{%
  \newcommand*{\sls@footabove@linethickness}{0pt}%
}
\KOMA@kav@xadd{.scrlayer-scrpage.sty}{footsepline}{%
  \expandafter\noexpand\sls@footabove@linethickness:%
  \expandafter\noexpand\sls@footabove@linelength}
\scrlayerAddToInterface\sls@footbelow@linelength{%
  \newcommand*{\sls@footbelow@linelength}{\sls@footwidth}%
}
\scrlayerAddToInterface\sls@footbelow@linethickness{%
  \newcommand*{\sls@footbelow@linethickness}{0pt}%
}
\KOMA@kav@xadd{.scrlayer-scrpage.sty}{footbotline}{%
  \expandafter\noexpand\sls@footbelow@linethickness:%
  \expandafter\noexpand\sls@footbelow@linelength}
%</options>
%    \end{macrocode}
% \end{macro}^^A \sls@footbelow@linethickness
% \end{macro}^^A \sls@footbelow@linelength
% \end{macro}^^A \sls@footabove@linethickness
% \end{macro}^^A \sls@footabove@linelength
% \end{macro}^^A \sls@headbelow@linethickness
% \end{macro}^^A \sls@headbelow@linelength
% \end{macro}^^A \sls@headabove@linethickness
% \end{macro}^^A \sls@headabove@linelength
% \end{option}^^A footbotline
% \end{option}^^A footsepline
% \end{option}^^A headsepline
% \end{option}^^A headtopline
%
% \begin{option}{plainheadtopline}
% \begin{macro}{\ifsls@plain@head@above@line}
% \begin{option}{plainheadsepline}
% \begin{macro}{\ifsls@plain@head@below@line}
% \begin{option}{plainfootsepline}
% \begin{macro}{\ifsls@plain@foot@above@line}
% \begin{option}{plainfootbotline}
% \begin{macro}{\ifsls@plain@foot@below@line}
% \begin{description}
% \item[\texttt{=\meta{switch value}}:]
% \end{description}\noindent
% While these only switches the rule on or off, we need only some switches.
%    \begin{macrocode}
%<*options>
\scrlayerAddCsToInterface{ifsls@plain@head@above@line}{%
  \KOMA@ifkey{plainheadtopline}{sls@plain@head@above@line}%
  \scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@plainheadtopline}%
  \scrlayer@AddCsToInterface{%
    KV@KOMA.scrlayer-scrpage.sty@plainheadtopline@default}%
  \scrlayer@AddCsToInterface{sls@plain@head@above@linetrue}
  \scrlayer@AddCsToInterface{sls@plain@head@above@linefalse}
}
\scrlayerAddCsToInterface{ifsls@plain@head@sbelow@line}{%
  \KOMA@ifkey{plainheadsepline}{sls@plain@head@below@line}%
  \scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@plainheadsepline}%
  \scrlayer@AddCsToInterface{%
    KV@KOMA.scrlayer-scrpage.sty@plainheadsepline@default}%
  \scrlayer@AddCsToInterface{sls@plain@head@below@linetrue}%
  \scrlayer@AddCsToInterface{sls@plain@head@below@linefalse}%
}
\scrlayerAddCsToInterface{ifsls@plain@foot@above@line}{%
  \KOMA@ifkey{plainfootsepline}{sls@plain@foot@above@line}%
  \scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@plainfootsepline}%
  \scrlayer@AddCsToInterface{%
    KV@KOMA.scrlayer-scrpage.sty@plainfootsepline@default}%
  \scrlayer@AddCsToInterface{sls@plain@foot@above@linetrue}%
  \scrlayer@AddCsToInterface{sls@plain@foot@above@linefalse}%
}
\scrlayerAddCsToInterface{ifsls@plain@foot@below@line}{%
  \KOMA@ifkey{plainfootbotline}{sls@plain@foot@below@line}%
  \scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@plainfootbotline}%
  \scrlayer@AddCsToInterface{%
    KV@KOMA.scrlayer-scrpage.sty@plainfootbotline@default}%
  \scrlayer@AddCsToInterface{sls@plain@foot@below@linetrue}%
  \scrlayer@AddCsToInterface{sls@plain@foot@below@linefalse}%
}
%</options>
%    \end{macrocode}
% \end{macro}^^A \ifsls@plain@foot@below@line
% \end{option}^^A plainfootbotline
% \end{macro}^^A \ifsls@plain@foot@above@line
% \end{option}^^A plainfootsepline
% \end{macro}^^A \ifsls@plain@head@below@line
% \end{option}^^A plainheadsepline
% \end{macro}^^A \ifsls@plain@head@above@line
% \end{option}^^A plainheadtopline
%
% \begin{option}{ilines}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{option}{clines}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{option}{olines}
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
% \begin{macro}{\sls@hfline@adjust}
% Maybe it would be more useful to be able to adjust each line on its own or
% at most to define an offset. But \Package{scrpage2} supports only these
% options. At least we can set the options inside a layer or page style. This
% may help.
%    \begin{macrocode}
%<*options>
\scrlayerAddToInterface\sls@hfline@adjust{%
  \newcommand*{\sls@hfline@adjust}{0}%
}
\KOMA@kav@add{.scrlayer-scrpage.sty}{ilines}{}
\KOMA@key{ilines}[]{%
  \ifx\relax#1\relax
    \renewcommand*{\sls@hfline@adjust}{0}%
    \FamilyKeyStateProcessed
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{ilines}%
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{clines}%
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{olines}%
    \KOMA@kav@add{.scrlayer-scrpage.sty}{ilines}{}%
  \else
    \def\FamilyKeyStateProcessed{unexpected value}%
  \fi
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@ilines}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@ilines@default}
\KOMA@key{clines}[]{%
  \ifx\relax#1\relax
    \renewcommand*{\sls@hfline@adjust}{1}%
    \FamilyKeyStateProcessed
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{ilines}%
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{clines}%
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{olines}%
    \KOMA@kav@add{.scrlayer-scrpage.sty}{clines}{}%
  \else
    \def\FamilyKeyStateProcessed{unexpected value}%
  \fi
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@clines}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@clines@default}
\KOMA@key{olines}[]{%
  \ifx\relax#1\relax
    \renewcommand*{\sls@hfline@adjust}{2}%
    \FamilyKeyStateProcessed
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{ilines}%
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{clines}%
    \KOMA@kav@removekey{.scrlayer-scrpage.sty}{olines}%
    \KOMA@kav@add{.scrlayer-scrpage.sty}{olines}{}%
  \else
    \def\FamilyKeyStateProcessed{unexpected value}%
  \fi
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@olines}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@olines@default}
\KOMA@kav@add{.scrlayer-scrpage.sty}{ilines}{}
%</options>
%    \end{macrocode}
% \end{macro}^^A \sls@hfline@adjust
% \end{option}^^A olines
% \end{option}^^A clines
% \end{option}^^A ilines
%
% \begin{macro}{\setheadtopline}
% \begin{macro}{\setheadsepline}
% \begin{macro}{\setfootsepline}
% \begin{macro}{\setfootbotline}
%   \begin{description}
%   \item[\OParameter{extended dimensional expression}:] the length of the
%     line; if omitted the length will use the width of the page head or
%     footer while printing the line.
%   \item[\Parameter{dimensional expression}:] the thickness of the line.
%   \item[\OParameter{code}:] the font selection code for the line. You may
%     use it for any kind of operation, that doesn't change the position,
%     width, height, or depth, e.g., to change the colour of the line.
%   \end{description}
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\setheadtopline{%
  \newcommand*{\setheadtopline}{\sls@setline{head}{above}}%
}
\scrlayerAddToInterface\setheadsepline{%
  \newcommand*{\setheadsepline}{\sls@setline{head}{below}}%
}
\scrlayerAddToInterface\setfootsepline{%
  \newcommand*{\setfootsepline}{\sls@setline{foot}{above}}%
}
\scrlayerAddToInterface\setfootbotline{%
  \newcommand*{\setfootbotline}{\sls@setline{foot}{below}}%
}
%    \end{macrocode}
% \begin{macro}{\sls@setline}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\sls@@setline}
% \begin{macro}{\sls@@@setline}
%   \changes{v3.17}[2015/02/27]{internal use of the corresponding options}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\sls@@@@setline}
%   \changes{v3.18}{2015/06/17}{explicit reuse of the current length}^^A
% Helper to set up the line attributes processing the parameters of the
% commands above.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@setline{%
  \newcommand*\sls@setline[2]{%
    \kernel@ifnextchar[%]
    {\sls@@setline{#1}{#2}}{\sls@@@setline{#1#2}}%
  }%
}
\scrlayerAddToInterface\sls@@setline{%
  \def\sls@@setline#1#2[#3]{%
    \ifstr{#3}{auto}{%
      \sls@deftowidthof{sls@#1#2@linelength}{#3#1}%
    }{%
      \sls@deftowidthof{sls@#1#2@linelength}{#3}%
    }%
    \sls@@@setline{#1#2}%
  }%
}
\scrlayerAddToInterface\sls@@@setline{%
  \def\sls@@@setline#1#2{%
    \edef\@tempa{#2}\edef\@tempb{current}%
    \ifstr{#2}{}{}{%
      \ifstr{#2}{current}{}{%
        \setlength{\@tempdima}{#2}%
        \ifstr{#1}{headabove}{%
          \KOMAExecuteOptions[.scrlayer-scrpage.sty]%
            {headtopline=\@tempdima:\csname sls@#1@linelength\endcsname}%
        }{\ifstr{#1}{headbelow}{%
            \KOMAExecuteOptions[.scrlayer-scrpage.sty]%
              {headsepline=\@tempdima:\csname sls@#1@linelength\endcsname}%
          }{%
            \ifstr{#1}{footabove}{%
              \KOMAExecuteOptions[.scrlayer-scrpage.sty]%
                {footsepline=\@tempdima:\csname sls@#1@linelength\endcsname}%
            }{%
              \KOMAExecuteOptions[.scrlayer-scrpage.sty]%
                {footbotline=\@tempdima:\csname sls@#1@linelength\endcsname}%
            }%
          }%
        }%
      }%
    }%
    \PackageWarning{scrlayer-scrpage}{%
      Command deprecated!\MessageBreak
      Usage of `\string\setheadtopline',
      `\string\setheadsepline',\MessageBreak
      `\string\setfootsepline', and `\string\setfootbotline'\MessageBreak
      became deprecated with scrlayer-scrpage.\MessageBreak
      You should use KOMA-Script options\MessageBreak
      `headsepline', `headtopline', `footsepline',\MessageBreak
      or `footbotline' with values\MessageBreak
      `<line thickness>:<line length>' to setup\MessageBreak
      the line length and thickness, and\MessageBreak
      `\string\setkomafont' or `\string\addtokomafont' to\MessageBreak
      setup the colour%
    }%
    \kernel@ifnextchar[%]
    {%
      \sls@@@@setline{#1}%
    }{%
    }%
  }%
}
\scrlayerAddToInterface\sls@@@@setline{%
  \def\sls@@@@setline#1[#2]{%
    \ifstr{#1}{headabove}{\setkomafont{headtopline}{#2}}{%
      \ifstr{#1}{headbelow}{\setkomafont{headsepline}{#2}}{%
        \ifstr{#1}{footabove}{\setkomafont{footsepline}{#2}}{%
          \setkomafont{footbotline}{#2}%
        }%
      }%
    }%
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@setline
% \end{macro}^^A \sls@@setline
% \end{macro}^^A \sls@@@setline
% \end{macro}^^A \sls@@@@setline
% \begin{KOMAfont}{headtopline}
% \begin{KOMAfont}{headsepline}
% \begin{KOMAfont}{footsepline}
% \begin{KOMAfont}{footbotline}
% These are the font elements used in \Macro{sls@hf@rule} to set the rules
% with, i.e., another colour. Note, that those may already be defined and
% become only part of the interface if they are not.
%    \begin{macrocode}
\@ifundefined{scr@fnt@headtopline}{%
  \@ifundefined{@headtoplinefont}{%
    \scrlayer@AddCsToInterface{@headtoplinefont}%
  }{}%
  \newkomafont{headtopline}{}%
  \scrlayer@AddCsToInterface{scr@fnt@headtopline}%
}{}
\@ifundefined{scr@fnt@headsepline}{%
  \@ifundefined{@headseplinefont}{%
    \scrlayer@AddCsToInterface{@headseplinefont}%
  }{}%
  \newkomafont{headsepline}{}%
  \scrlayer@AddCsToInterface{scr@fnt@headsepline}%
}{}
\@ifundefined{scr@fnt@footsepline}{%
  \@ifundefined{@footseplinefont}{%
    \scrlayer@AddCsToInterface{@footseplinefont}%
  }{}%
  \newkomafont{footsepline}{}%
  \scrlayer@AddCsToInterface{scr@fnt@footsepline}%
}{}
\@ifundefined{scr@fnt@footbotline}{%
  \@ifundefined{@footbotlinefont}{%
    \scrlayer@AddCsToInterface{@footbotlinefont}%
  }{}%
  \newkomafont{footbotline}{}%
  \scrlayer@AddCsToInterface{scr@fnt@footbotline}%
}{}
%</body>
%    \end{macrocode}
% \end{KOMAfont}^^A footbotline
% \end{KOMAfont}^^A footsepline
% \end{KOMAfont}^^A headsepline
% \end{KOMAfont}^^A headtopline
% \end{macro}^^A \setfootbotline
% \end{macro}^^A \setfootsepline
% \end{macro}^^A \setheadsepline
% \end{macro}^^A \setheadtopline
%
% \begin{length}{\headheight}
% Some classes set \Length{headheight} to a very, very small value. We'll
% warn about that:
%    \begin{macrocode}
%<*body>
\AtBeginDocument{%
  \ifdim \headheight <\baselineskip
    \PackageWarningNoLine{scrlayer-scrpage}{Very small head height
      detected!\MessageBreak
      Using scrlayer-scrpage the head height\MessageBreak
      should be at least \string\baselineskip, which is\MessageBreak
      \the\baselineskip\space currently.\MessageBreak
      But head height is currently
      \the\headheight\space only.\MessageBreak
      You may use\MessageBreak
      \@ifpackageloaded{geometry}{%
        geometry option `head=\the\baselineskip'%
      }{%
        \@ifpackageloaded{typearea}{%
          typearea option `headheight=\the\baselineskip'%
        }{%
          \string\setlength{\string\headheight}{\the\baselineskip}%
        }%
      }\MessageBreak
      to avoid this warning%
    }%
  \fi
}
%</body>
%    \end{macrocode}
% \end{length}
%
%
% \section{Style of Running Heads}
%
% This implements not only options \Option{komastyle} and
% \Option{standardstyle} of \Package{scrpage2}, but also activates the default
% style at the end of the package and takes care for the correct overwrite
% behaviour of option \Option{markcase}.
%
% \begin{option}{pagestyleset}
%   \begin{description}
%   \item[\texttt{=\meta{string}}:] a valid name of a predefined
%     style-set. Currently only \texttt{KOMA-Script} and \texttt{standard} are
%     supported. Maybe more will follow.
%   \end{description}
% Note, that the following automatic style activation must be before the
% first option usage:
%    \begin{macrocode}
%<*init>
\AtEndOfPackage{%
  \sls@auto@pagestyleset%
}
%    \end{macrocode}
% \begin{macro}{\sls@auto@pagestyleset}
%   \changes{v0.9}{2014/01/22}{new (internal) macro}%^^A
%    \begin{macrocode}
\newcommand*{\sls@auto@pagestyleset}{%
  \scr@ifundefinedorrelax{KOMAClassName}{%
%<trace>    \PackageInfoNoLine{scrlayer-scrpage}{%
%<trace>      auto-selection of `pagestyleset=standard'}%
    \FamilyExecuteOptions[.scrlayer-scrpage.sty]{KOMA}{pagestyleset=standard}%
  }{%
%<trace>    \PackageInfoNoLine{scrlayer-scrpage}{%
%<trace>      auto-selection of `pagestyleset=KOMA-Script'}%
    \FamilyExecuteOptions[.scrlayer-scrpage.sty]{KOMA}%
    {pagestyleset=KOMA-Script}%
  }%
}
%</init>
%    \end{macrocode}
% \end{macro}%^^A \sls@auto@pagestyleset
%   \changes{v3.17}{2015/02/25}{new: store the values}^^A
%    \begin{macrocode}
%<*options>
\KOMA@key{pagestyleset}{%
  \scr@ifundefinedorrelax{sls@ps@style@#1}{%
    \FamilyKeyStateUnknownValue
  }{%
    \let\sls@auto@pagestyleset\relax
    \@nameuse{sls@ps@style@#1}%
    \FamilyKeyStateProcessed
    \KOMA@kav@replacevalue{.scrlayer-scrpage.sty}{pagestyleset}{#1}%
  }%
}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@pagestyleset}
%    \end{macrocode}
% \begin{macro}{\sls@ps@style@standard}
% \begin{macro}{\sls@ps@style@KOMA-Script}
% These are the predefined page style sets.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@ps@style@standard{%
  \newcommand*{\sls@ps@style@standard}{%
    \let\MakeMarkcase\MakeUppercase
    \scrlayer@AtEndOfPackage{%
      \pagestyle{scrheadings}%
      \clearpairofpagestyles
      \ihead{\headmark}%
      \ohead{\pagemark}%
      \cfoot[\if@twoside\else\pagemark\fi]{}%
    }%
  }%
}
\scrlayerAddCsToInterface{sls@ps@style@KOMA-Script}{%
  \@namedef{sls@ps@style@KOMA-Script}{%
    \let\MakeMarkcase\@firstofone
    \scrlayer@AtEndOfPackage{%
      \pagestyle{scrheadings}%
      \clearpairofpagestyles
      \ohead{\if@twoside\headmark\fi}%
      \chead{\if@twoside\else\headmark\fi}%
      \ofoot[\if@twoside\pagemark\fi]{\if@twoside\pagemark\fi}%
      \cfoot[\if@twoside\else\pagemark\fi]{\if@twoside\else\pagemark\fi}%
      \scr@ifundefinedorrelax{KOMAClassName}{}{%
        \ifstr{\KOMAClassName}{scrlttr2}{%
%    \end{macrocode}
% We are using \Class{scrlttr2}, so we have to initialise the page style
% different:
%   \changes{v3.18}{2015/06/24}{missing \cs{lofoot} and \cs{rofoot} added}^^A
%    \begin{macrocode}
          \clearpairofpagestyles
          \lehead[\ifnum\@pageat=\z@\pagemark\fi]
                 {\ifnum\@pageat=\z@\pagemark\else\leftmark\fi}%
          \lohead[\ifnum\@pageat=\z@\pagemark\fi]
                 {\ifnum\@pageat=\z@\pagemark\else\leftmark\fi}%
          \chead[\ifnum\@pageat=\@ne\pagemark\fi]
                {\ifcase\@pageat \rightmark\or \pagemark\or \rightmark\fi}%
          \rehead[\ifnum\@pageat=\tw@\pagemark\fi]
                 {\ifcase\@pageat \leftmark\or \rightmark\or \pagemark
                   \else \rightmark\fi}%
          \rohead[\ifnum\@pageat=\tw@\pagemark\fi]
                 {\ifcase\@pageat \leftmark\or \rightmark\or \pagemark
                   \else \rightmark\fi}%
          \lefoot[\ifnum\@pageat=\thr@@\pagemark\fi]
                 {\ifnum\@pageat=\thr@@\pagemark\fi}%
          \lofoot[\ifnum\@pageat=\thr@@\pagemark\fi]
                 {\ifnum\@pageat=\thr@@\pagemark\fi}%
          \cfoot[\ifnum\@pageat=4 \pagemark\fi]
                {\ifnum\@pageat=4 \pagemark\fi}%
          \refoot[\ifnum\@pageat=5 \pagemark\fi]
                 {\ifnum\@pageat=5 \pagemark\fi}%
          \rofoot[\ifnum\@pageat=5 \pagemark\fi]
                 {\ifnum\@pageat=5 \pagemark\fi}%
        }{}%
      }%
    }%
  }%
}
%</options>
%    \end{macrocode}
% \end{macro}^^A \sls@ps@style@KOMA-Script
% \end{macro}^^A \sls@ps@style@standard
% \end{option}^^A pagestyleset
%
% \begin{option}{komastyle}
% \begin{option}{standardstyle}
% These options are deprecated, but defined for compatibility with
% \Package{scrpage2}:
%    \begin{macrocode}
%<*options>
\KOMA@DeclareDeprecatedOption[scrlayer-scrpage]{komastyle}{%
  pagestyleset=KOMA-Script}
\KOMA@DeclareDeprecatedOption[scrlayer-scrpage]{standardstyle}{%
  pagestyleset=standard}
%</options>
%    \end{macrocode}
% \end{option}^^A standardstyle
% \end{option}^^A komastyle
%
%
% \section{Extended Mark Mechanisms}
%
% Package options \Option{markuppercase}, \Option{markusedcase}, and
% \Option{nouppercase} of package \Package{scrpage2} will be mapped to
% \KOMAScript{} option \Option{markcase}.
%
% \begin{option}{markuppercase}
% \begin{option}{markusedcase}
% \begin{option}{nouppercase}
% For compatibility with \Package{scrpage2}.
%    \begin{macrocode}
%<*options>
\KOMA@DeclareDeprecatedOption[scrlayer-scrpage]{markuppercase}{markcase=upper}
\KOMA@DeclareDeprecatedOption[scrlayer-scrpage]{markusedcase}{markcase=used}
\KOMA@DeclareDeprecatedOption[scrlayer-scrpage]{nouppercase}{%
  markcase=ignoreuppercase%
}
%</options>
%    \end{macrocode}
% \end{option}^^A nouppercase
% \end{option}^^A markusedcase
% \end{option}^^A markuppercase
%
%
% \section{Expert Page Style Definition Interface}
%
% This is the low level interface of \Package{scrpage2} with
% \Macro{defpagestyle}, \Macro{newpagestyle}, \Macro{renewpagestyle}, and
% \Macro{providepagestyle}. We will also define is. In difference to
% \Package{scrpage2} layers are used. Following layers will be defined for
% each page style:
% \begin{description}
% \item[\texttt{\meta{page style name}.head.above.line}] line above the head
% \item[\texttt{\meta{page style name}.head.odd}] odd page head (only twoside)
% \item[\texttt{\meta{page style name}.head.even}] even page head (only
%   twoside)
% \item[\texttt{\meta{page style name}.head.oneside}] single-side head (only
%   oneside)
% \item[\texttt{\meta{page style name}.head.below}] line below the head
% \item[\texttt{\meta{page style name}.foot.above.line}] line above the footer
% \item[\texttt{\meta{page style name}.foot.odd}] odd page footer (only
%   twoside)
% \item[\texttt{\meta{page style name}.foot.even}] even side footer (only
%   twoside)
% \item[\texttt{\meta{page style name}.foot.oneside}] single-side footer (only
%   oneside)
% \item[\texttt{\meta{page style name}.foot.below.line}] line below the footer
%   (only oneside)
% \end{description}
% Note: \Package{scrpage2} also provides starred versions of the page style
% definition commands, doing the same like the starless versions. This has
% been done for compatibility reasons with deprecated \Package{scrpage2} and
% may be removed some times. The layer interface doesn't support this.
%
% \begin{macro}{\defpagestyle}
%   \begin{description}
%   \item[\Parameter{string}:] the name of the page style to be defined (must
%     be fully expandable and expand to a string only).
%   \item[\Parameter{head/foot definition}:] will be used to define the
%     head (see \Macro{sls@defhead}).
%   \item[\Parameter{head/foot definition}:] will be used to define the
%     foot (see \Macro{sls@deffoot}).
%   \end{description}
% See \Package{scrpage2} implementation.
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\defpagestyle{%
  \newcommand*{\defpagestyle}[3]{%
    \sls@defhead{#1}#2\@empty\@empty\@empty
    \sls@deffoot{#1}#3\@empty\@empty\@empty 
    \DeclarePageStyleByLayers{#1}{%
      #1.head.odd,#1.head.even,#1.head.oneside,%
      #1.head.above.line,#1.head.below.line,%
      #1.foot.odd,#1.foot.even,#1.foot.oneside,%
      #1.foot.above.line,#1.foot.below.line%
    }%
    \edef\reserved@a{%
      \noexpand\scrlayerOnAutoRemoveInterface[scrlayer-scrpage.sty]{%
        \noexpand\DestroyLayer{#1.head.odd}%
        \noexpand\DestroyLayer{#1.head.even}%
        \noexpand\DestroyLayer{#1.head.oneside}%
        \noexpand\DestroyLayer{#1.head.above.line}%
        \noexpand\DestroyLayer{#1.head.below.line}%
        \noexpand\DestroyLayer{#1.foot.odd}%
        \noexpand\DestroyLayer{#1.foot.even}%
        \noexpand\DestroyLayer{#1.foot.oneside}%
        \noexpand\DestroyLayer{#1.foot.above.line}%
        \noexpand\DestroyLayer{#1.foot.below.line}%
        \noexpand\ifstr{\noexpand\currentpagestyle}{#1}{%
          \noexpand\PackageWarning{scrlayer-scrpage}{%
            page style `#1' not longer valid.\noexpand\MessageBreak
            The page style has been defined using\noexpand\MessageBreak
            interface `scrlayer-scrpage.sty', that\noexpand\MessageBreak
            has been removed%
          }%
        }{}%
        \noexpand\DestroyRealLayerPageStyle{#1}%
      }%
    }\reserved@a
  }%
}
%    \end{macrocode}
% \begin{macro}{\sls@defhead}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\sls@@defhead}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\sls@@@defhead}
%   \changes{v0.9}{2014/08/18}{fix names of layers \texttt{\dots head.odd} and
%     \texttt{\dots head.even}}%^^A
%   \begin{description}
%   \item[\MParameter{dimensional expression}{dimensional expression}:] length
%     and thickness of a line (ruler) above the page head. May be omitted and
%     if so the values from option \Option{headtopline} will be used.
%   \item[\Parameter{code}:] will be executed on even pages; used to define
%     the contents of layer \texttt{\meta{page style name}.head.even}.
%   \item[\Parameter{code}:] will be executed on odd pages within two-side
%     layout; used to define the contents of layer \texttt{\meta{page style
%     name}.head.odd}.
%   \item[\Parameter{code}:] will be executed on single-side pages; used to
%     define the contents of layer \texttt{\meta{page style
%     name}.head.oneside}.
%   \item[\MParameter{dimensional expression}{dimensional expression}:] length
%     and thickness of a line (ruler) below the page head. May be omitted and
%     if so the values from option \Option{headsepline} will be used.
%   \end{description}
% Helper to define the head layers.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@defhead{%
  \newcommand*\sls@defhead[1]{%
    \kernel@ifnextchar(%)
    {\sls@@defhead{#1}}%
    {\sls@@defhead{#1}(\sls@headabove@linelength,\sls@headabove@linethickness)}%
  }%
}
\scrlayerAddToInterface\sls@@defhead{%
  \def\sls@@defhead#1(#2,#3)#4#5#6{%
    \kernel@ifnextchar(%)
    {\sls@@@defhead{#1}({#2},{#3}){#4}{#5}{#6}}%
    {\sls@@@defhead{#1}%
                   ({#2},{#3})%
                   {#4}{#5}{#6}%
                   (\sls@headbelow@linelength,\sls@headbelow@linethickness)}%
  }%
}
\scrlayerAddToInterface\sls@@@defhead{%
  \def\sls@@@defhead#1(#2,#3)#4#5#6(#7,#8){%
%    \end{macrocode}
% The lines:
%    \begin{macrocode}
    \DeclareLayer[%
      background,%
      hoffset=\sls@leftmargin{head},%
      voffset=\sls@topmargin+\dp\strutbox,%
      width=\sls@headwidth,%
      height=0pt,%
      align=bl,%
      contents={%
        {\normalfont\usekomafont{pageheadfoot}{\usekomafont{pagehead}{%
              \sls@hf@rule{headtop}{#2}{#3}}}}%
      }%
    ]{#1.head.above.line}%
    \DeclareLayer[%
      background,%
      hoffset=\sls@leftmargin{head},%
      voffset=\sls@topmargin+\headheight-\ht\strutbox+#8,%
      width=\sls@headwidth,%
      height=0pt,%
      align=tl,%
      contents={%
        {\normalfont\usekomafont{pageheadfoot}{\usekomafont{pagehead}{%
              \sls@hf@rule{headsep}{#7}{#8}}}}%
      }%
    ]{#1.head.below.line}%
%    \end{macrocode}
% The odd side, even side and one side:
% \changes{v3.13b}{2014/10/16}{workaround: additional group added to avoid
%   pdf\TeX{} color stack warnings}%^^A
%    \begin{macrocode}
    \DeclareLayer[%
      background,evenpage,twoside,%
      head,%
      hoffset=\sls@leftmargin{head},%
      width=\sls@headwidth,%
      contents={%
        \sls@secure@box\headheight{%
          \normalfont{\usekomafont{pageheadfoot}{\usekomafont{pagehead}{#4}}}}}%
    ]{#1.head.even}%
    \DeclareLayer[%
      background,oddpage,twoside,%
      head,%
      hoffset=\sls@leftmargin{head},%
      width=\sls@headwidth,%
      contents={%
        \sls@secure@box\headheight{%
          \normalfont{\usekomafont{pageheadfoot}{\usekomafont{pagehead}{#5}}}}}%
    ]{#1.head.odd}%
    \DeclareLayer[%
      background,oddpage,oneside,%
      head,%
      hoffset=\sls@leftmargin{head},%
      width=\sls@headwidth,%
      contents={%
        \sls@secure@box\headheight{%
          \normalfont{\usekomafont{pageheadfoot}{\usekomafont{pagehead}{#6}}}}}%
    ]{#1.head.oneside}%
  }%
}
%    \end{macrocode}
% \begin{macro}{\sls@deffoot}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\sls@@deffoot}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\sls@@@deffoot}
%   \changes{v0.9}{2014/08/18}{fix names of layers \texttt{\dots foot.odd} and
%     \texttt{\dots foot.even}}%^^A
%   \begin{description}
%   \item[\MParameter{dimensional expression}{dimensional expression}:] length
%     and thickness of a line (ruler) above the page footer. May be omitted
%     and if so the values from option \Option{footsepline} will be used.
%   \item[\Parameter{code}:] will be executed on even pages; used to define
%     the contents of layer \texttt{\meta{page style name}.foot.even}.
%   \item[\Parameter{code}:] will be executed on odd pages within two-side
%     layout; used to define the contents of layer \texttt{\meta{page style
%     name}.foot.odd}.
%   \item[\Parameter{code}:] will be executed on single-side pages; used to
%     define the contents of layer \texttt{\meta{page style
%     name}.foot.oneside}.
%   \item[\MParameter{dimensional expression}{dimensional expression}:] length
%     and thickness of a line (ruler) below the page footer. May be omitted
%     and if so the values from option \Option{footbotline} will be used.
%   \end{description}
% Helper to define the foot layers.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@deffoot{%
  \newcommand*\sls@deffoot[1]{%
    \kernel@ifnextchar(%)
    {\sls@@deffoot{#1}}%
    {\sls@@deffoot{#1}(\sls@footabove@linelength,\sls@footabove@linethickness)}%
  }%
}
\scrlayerAddToInterface\sls@@deffoot{%
  \def\sls@@deffoot#1(#2,#3)#4#5#6{%
    \kernel@ifnextchar(%)
    {\sls@@@deffoot{#1}({#2},{#3}){#4}{#5}{#6}}%
    {\sls@@@deffoot{#1}%
                   ({#2},{#3})%
                   {#4}{#5}{#6}%
                   (\sls@footbelow@linelength,\sls@footbelow@linethickness)}%
  }%
}
\scrlayerAddToInterface\sls@@@deffoot{%
  \def\sls@@@deffoot#1(#2,#3)#4#5#6(#7,#8){%
%    \end{macrocode}
% The lines:
%    \begin{macrocode}
    \DeclareLayer[%
      foreground,%
      hoffset=\sls@leftmargin{foot},%
      voffset=\sls@topmargin
              +\headheight+\headsep
              +\textheight
              +\footskip-\footheight
              +2\dp\strutbox,%
      width=\sls@footwidth,%
      height=0pt,%
      align=bl,%
      contents={%
        {\normalfont\usekomafont{pageheadfoot}{\usekomafont{pagefoot}{%
              \sls@hf@rule{footsep}{#2}{#3}}}}%
      }%
    ]{#1.foot.above.line}%
    \DeclareLayer[%
      foreground,%
      hoffset=\sls@leftmargin{foot},%
      voffset=\sls@topmargin
              +\headheight+\headsep
              +\textheight
              +\footskip
              +2\dp\strutbox
              +#8,%
      width=\sls@footwidth,%
      height=0pt,%
      align=bl,%
      contents={%
        {\normalfont\usekomafont{pageheadfoot}{\usekomafont{pagefoot}{%
              \sls@hf@rule{footbot}{#7}{#8}}}}%
      }%
    ]{#1.foot.below.line}%
%    \end{macrocode}
% The odd side, even side and one side:
%    \begin{macrocode}
    \DeclareLayer[%
      foreground,evenpage,twoside,%
      foot,%
      hoffset=\sls@leftmargin{foot},%
      width=\sls@footwidth,%
      contents={%
        \sls@secure@box\footheight{%
          \normalfont\usekomafont{pageheadfoot}{\usekomafont{pagefoot}{#4}}}}%
    ]{#1.foot.even}%
    \DeclareLayer[%
      foreground,oddpage,twoside,%
      foot,%
      hoffset=\sls@leftmargin{foot},%
      width=\sls@footwidth,%
      contents={%
        \sls@secure@box\footheight{%
          \normalfont\usekomafont{pageheadfoot}{\usekomafont{pagefoot}{#5}}}}%
    ]{#1.foot.odd}%
    \DeclareLayer[%
      foreground,oddpage,oneside,%
      foot,%
      hoffset=\sls@leftmargin{foot},%
      width=\sls@footwidth,%
      contents={%
        \sls@secure@box\footheight{%
          \normalfont\usekomafont{pageheadfoot}{\usekomafont{pagefoot}{#6}}}}%
    ]{#1.foot.oneside}%
  }%
}
%    \end{macrocode}
% \begin{macro}{\sls@secure@box}
%   \begin{description}
%   \item[\Parameter{length}:] a \LaTeX{} length, that gives the maximum
%     height + depth of the \meta{content}. It has to be either
%     \cs{headheight} or \cs{footheight}.
%   \item[\Parameter{content}:] what should be output (inside the box).
%   \end{description}
% Note, that several length may be changed, to fit.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@secure@box{%
  \newcommand*{\sls@secure@box}[2]{%
    \begingroup
      \setbox\z@\vbox{%
        \ifsls@leavevmode\leavevmode\expandafter\ignorespaces\fi 
        #2%
      }%
      \ifdim #1<\dimexpr \ht\z@+\dp\z@\relax
        \PackageWarning{scrlayer-scrpage}{%
          \string#1 to low.\MessageBreak
          At least \the\dimexpr \ht\z@+\dp\z@\relax\space needed,\MessageBreak
          but only \the#1 found.\MessageBreak
          I'll enlarge \string#1, for further\MessageBreak
          processing, but you should do this yourself,\MessageBreak
          e.g.,
          \scr@ifundefinedorrelax{geometry}{%
            \scr@ifundefinedorrelax{typearea}{%
              using\MessageBreak
              \space\space\string\setlength{\string#1}{%
                \the\dimexpr \ht\z@+\dp\z@\relax}\MessageBreak
              in your preamble%
            }{%
              setting typearea's option\MessageBreak
              `\expandafter\@gobble\string#1=\the\dimexpr \ht\z@+\dp\z@\relax'%
            }%
          }{%
            \ifx #1\headheight
              setting geometry's option\MessageBreak
              `head=\the\dimexpr \ht\z@+\dp\z@\relax'%
            \else
              using\MessageBreak
              \space\space\string\setlength{\string#1}{%
                \the\dimexpr \ht\z@+\dp\z@\relax}\MessageBreak
              in your preamble%
            \fi
          }%
          .\MessageBreak
          I'll also
          \ifx #1\headheight decrease \string\topmargin
          \else increase \string\footskip\fi
        }%
        \@tempdima\dimexpr \ht\z@+\dp\z@\relax
        \ifx #1\headheight
          \global\advance\topmargin by \dimexpr #1-(\ht\z@+\dp\z@)\relax
          \dp\z@\dimexpr \dp\z@+\ht\z@+\dp\z@-\headheight\relax
        \else
          \global\advance\footskip by \dimexpr \ht\z@+\dp\z@-#1\relax
        \fi
        \global#1\@tempdima
      \fi
      \usebox\z@
    \endgroup
  }%
}
%</body>
%    \end{macrocode}
% \begin{option}{hmode}
% Switch automatically to the horizontal mode before setting a page head or
% page footer element
%    \begin{macrocode}
%<*options>
\KOMA@ifkey{hmode}{sls@leavevmode}
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@hmode}%
\scrlayer@AddCsToInterface{KV@KOMA.scrlayer-scrpage.sty@hmode@default}%
\scrlayer@AddCsToInterface{sls@leavevmode@linetrue}
\scrlayer@AddCsToInterface{sls@leavevmode@linefalse}
%</options>
%    \end{macrocode}
% \end{option}
% \end{macro}^^A \sls@secure@box
% \end{macro}^^A \sls@@@deffoot
% \end{macro}^^A \sls@@deffoot
% \end{macro}^^A \sls@deffoot
% \end{macro}^^A \sls@@@defhead
% \end{macro}^^A \sls@@defhead
% \end{macro}^^A \sls@defhead
% \begin{macro}{\headfont}
% The low level page head font command. It is deprecated to redefine or use
% this and it may already be defined.
% \begin{macro}{\scr@fnt@pagehead}
% \begin{macro}{\scr@fnt@wrn@pagehead}
%   \changes{v0.9}{2014/01/13}{warning always deactivated}
% \begin{macro}{\scr@fnt@pageheadfoot}
%    \begin{macrocode}
%<*body>
\@ifundefined{scr@fnt@pagehead}{%
  \scrlayer@AddCsToInterface{scr@fnt@pagehead}%
  \@ifundefined{@pageheadfont}{%
    \newkomafont{pagehead}{}%
    \scrlayer@AddCsToInterface{@pageheadfont}%
  }{%
    \newcommand*{\scr@fnt@pagehead}{\@pageheadfont}%
  }%
}{}
\@ifundefined{scr@fnt@pageheadfoot}{%
  \newcommand*{\scr@fnt@pageheadfoot}{\headfont}%
  \scrlayer@AddCsToInterface{scr@fnt@pageheadfoot}%
  \@ifundefined{headfont}{%
    \newcommand*{\headfont}{\normalcolor\slshape}%
  }{}
}{}
\scr@ifundefinedorrelax{scr@fnt@wrn@pagehead}{}{%
%<trace>  \PackageInfo{scrlayer-scrpage}{%
%<trace>    deactivating warning for font element\MessageBreak
%<trace>    `pagehead'}%
  \let\scr@fnt@wrn@pagehead\relax
}
%    \end{macrocode}
% \end{macro}^^A \scr@fnt@pageheadfoot
% \end{macro}^^A \scr@fnt@wrn@pagehead
% \end{macro}^^A \scr@fnt@pagehead
% \end{macro}^^A \headfont
%
% \begin{macro}{\footfont}
% The low level page footer font command. It is deprecated to redefine or use
% this and it may already be defined.
% \begin{macro}{\scr@fnt@pagefoot}
% \begin{macro}{\scr@fnt@wrn@pagefoot}
%   \changes{v0.9}{2014/01/13}{warning always deactivated}
%    \begin{macrocode}
\@ifundefined{scr@fnt@pagefoot}{%
  \scrlayer@AddCsToInterface{scr@fnt@pagefoot}%
  \def\scr@fnt@pagefoot{\footfont}%
  \@ifundefined{footfont}{%
    \newcommand*{\footfont}{}%
    \scrlayer@AddCsToInterface{footfont}%
  }{}%
}{}
\scr@ifundefinedorrelax{scr@fnt@wrn@pagefoot}{}{%
%<trace>  \PackageInfo{scrlayer-scrpage}{%
%<trace>    deactivating warning for font element\MessageBreak
%<trace>    `pagefoot'}%
  \let\scr@fnt@wrn@pagefoot\relax
}
%    \end{macrocode}
% \end{macro}^^A \scr@fnt@wrn@pagefoot
% \end{macro}^^A \scr@fnt@pagefoot
% \end{macro}^^A \footfont
%
% \begin{macro}{\sls@hf@rule}
%   \begin{description}
%   \item[\Parameter{rule name}:] one of \texttt{headtop}, \texttt{headsep},
%     \texttt{footsep}, or \texttt{footbot}
%   \item[\Parameter{dimensional expression}:] the line length (width)
%   \item[\Parameter{dimensional expression}:] the line thickness (height)
%   \end{description}
% Helper to draw the line.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@hf@rule{%
  \newcommand*\sls@hf@rule[3]{%
    \begingroup
      \normalfont\usekomafont{#1line}{%
        \vbox to \z@{%
          \kern -\dimexpr #3\relax
          \ifnum \sls@hfline@adjust>\z@ \@tempswatrue \else \@tempswafalse\fi
          \if@twoside\ifodd\value{page}\else
            \ifnum \sls@hfline@adjust<\tw@ \@tempswatrue\else \@tempswafalse\fi
          \fi\fi
          \if@tempswa
            \hskip \z@\@plus 1fill\@minus \paperwidth
          \fi
          \vrule \@width\dimexpr #2\relax \@height\dimexpr #3\relax \@depth\z@
          \ifnum \sls@hfline@adjust<\tw@ \@tempswatrue\else \@tempswafalse\fi
          \if@twoside\ifodd\value{page}\else
            \ifnum \sls@hfline@adjust>\z@ \@tempswatrue \else \@tempswafalse\fi
          \fi\fi
          \if@tempswa
            \hskip \z@\@plus 1fill\@minus \paperwidth\null
          \fi
        }%
      }%      
    \endgroup
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@hf@rule
% \begin{macro}{\sls@topmargin}
% \begin{macro}{\sls@leftmargin}
% Two simple helper macros:
%    \begin{macrocode}
\scrlayerAddToInterface\sls@topmargin{%
  \newcommand*{\sls@topmargin}{\dimexpr\topmargin+1in\relax}%
}
\scrlayerAddToInterface\sls@leftmargin{%
  \newcommand*{\sls@leftmargin}[1]{%
    \dimexpr
    \if@twoside
      \ifodd\value{page}
        \oddsidemargin+\csname sls@odd#1shift\endcsname
      \else
        \evensidemargin+\csname sls@even#1shift\endcsname
      \fi
    \else
      \oddsidemargin+\csname sls@odd#1shift\endcsname
    \fi 
    +1in\relax
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \sls@leftmargin
% \end{macro}^^A \sls@topmargin
% \end{macro}^^A \defpagestyle
%
% \begin{macro}{\newpagestyle}
% For the parameters see \Macro{defpagestyle}.
% Define only, if not already defined:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\newpagestyle{%
  \newcommand*\newpagestyle[3]{%
    \@ifundefined{ps@#1}{\defpagestyle{#1}{#2}{#3}}{%
      \PackageError{scrlayer-scrpage}{Page style `#1' already defined}{%
        Only not yet defined page style may be defined using
        \string\newpagestyle.\MessageBreak
        You may use either \string\renewpagestyle, \string\providepagestyle,
        or \string\defpagestyle\MessageBreak
        with already defined page styles.\MessageBreak
        If you'll continue, your command will be ignored.%
      }%
    }%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \newpagestyle
%
% \begin{macro}{\renewpagestyle}
% For the parameters see \Macro{defpagestyle}.
% Define only, if not already defined:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\renewpagestyle{%
  \newcommand*\renewpagestyle[3]{%
    \@ifundefined{ps@#1}{%
      \PackageError{scrlayer-scrpage}{Undefined page style `#1'}{%
        Only already defined page style may be re-defined using
        \string\renewpagestyle.\MessageBreak
        You may use either \string\newpagestyle, \string\providepagestyle,
        or \string\defpagestyle\MessageBreak
        with not yet defined page styles.\MessageBreak
        If you'll continue, your command will be ignored.%
      }%
    }{%
      \defpagestyle{#1}{#2}{#3}%
    }%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \renewpagestyle
%
% \begin{macro}{\providepagestyle}
% For the parameters see \Macro{defpagestyle}.
% Define only, if not already defined:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\providepagestyle{%
  \newcommand*\providepagestyle[3]{%
    \@ifundefined{ps@#1}{%
      \defpagestyle{#1}{#2}{#3}%
    }{%
%<*trace>
      \PackageInfo{scrlayer-scrpage}{%
        page style `#1' already defined.\MessageBreak
        New definition ignored%
      }%
%</trace>
    }%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \providepagestyle
%
%
% \section{User Page Style Definition Interface}
%
% This is the mid-level interface of \Package{scrpage2} with
% \Macro{deftripstyle}. As in \Package{scrpage2} we simply use the expert page
% style definition interface to define the new user interface commands. But
% here the useless starred versions will not longer be supported. So users of
% them have to remove the star (nothing else).
%
% \begin{macro}{\deftriplepagestyle}
% \begin{macro}{\newtriplepagestyle}
% \begin{macro}{\renewtriplepagestyle}
% \begin{macro}{\providetriplepagestyle}
% \begin{macro}{\deftripstyle}
%   \begin{description}
%   \item[\Parameter{string}:] the name of the page style to be defined (must
%     be fully expandable and expand to a string only).
%   \item[\OParameter{dimensional expression}:] thickness of a horizontal line
%     above the page head and below the page foot (default: 0\,pt).
%   \item[\OParameter{dimensional expression}:] thickness of a horizontal line
%     below the page head and above the page foot (default: 0\,pt).
%   \item[\Parameter{code}:] will be expanded left aligned at head of odd
%     pages (with one-side layout all pages are odd) and right aligned at head
%     of even pages.
%   \item[\Parameter{code}:] will be expanded centered at head of odd
%     and even pages.
%   \item[\Parameter{code}:] will be expanded right aligned at head of odd
%     pages (with one-side layout all pages are odd) and left aligned at head
%     of even pages.
%   \item[\Parameter{code}:] will be expanded left aligned at footer of odd
%     pages (with one-side layout all pages are odd) and right aligned at
%     footer of even pages.
%   \item[\Parameter{code}:] will be expanded centered at footer of odd
%     and even pages.
%   \item[\Parameter{code}:] will be expanded right aligned at footer of odd
%     pages (with one-side layout all pages are odd) and left aligned at
%     footer of even pages.
%   \end{description}
% See \Package{scrpage2}, but:
% While the starred version of \Macro{deftripstyle} is deprecated for several
% years and hasn't been described at the manual, it will not longer be
% defined. Additional commands have been added.
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface{\deftriplepagestyle}{%
  \newcommand*{\deftriplepagestyle}[1]{%
    \let\@tempa\defpagestyle
    \scrlayer@triplestyle{#1}%
  }%
}
\scrlayerAddToInterface{\newtriplepagestyle}{%
  \newcommand*{\newtriplepagestyle}[1]{%
    \let\@tempa\newpagestyle
    \scrlayer@triplestyle{#1}%
  }%
}
\scrlayerAddToInterface{\renewtriplepagestyle}{%
  \newcommand*{\renewtriplepagestyle}[1]{%
    \let\@tempa\renewpagestyle
    \scrlayer@triplestyle{#1}%
  }%
}
\scrlayerAddToInterface{\providetriplepagestyle}{%
  \newcommand*{\providetriplepagestyle}[1]{%
    \let\@tempa\providepagestyle
    \scrlayer@triplestyle{#1}%
  }%
}
%    \end{macrocode}
% \begin{macro}{\scrlayer@triplestyle}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\scrlayer@@triplestyle}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\scrlayer@@@triplestyle}
% Helpers, that do the real work. Parameters are same, but \cs{reserved@a} has
% to be one of \Macro{defpagestyle}, \Macro{newpagestyle},
% \Macro{renewpagestyle}, or \Macro{providepagestyle}.
%    \begin{macrocode}
\scrlayerAddToInterface\scrlayer@triplestyle{%
  \def\scrlayer@triplestyle#1{%
    \kernel@ifnextchar[%]
    {\scrlayer@@triplestyle{#1}}%
    {\scrlayer@@triplestyle{#1}[\z@]}%
  }
}
\scrlayerAddToInterface\scrlayer@@triplestyle{%
  \def\scrlayer@@triplestyle#1[#2]{%
   \kernel@ifnextchar[%]
    {\scrlayer@@@triplestyle{#1}[#2]}%
    {\scrlayer@@@triplestyle{#1}[\z@][#2]}%
  }%
}
\scrlayerAddToInterface\scrlayer@@@triplestyle{%
  \def\scrlayer@@@triplestyle#1[#2][#3]#4#5#6#7#8#9{%
    \@tempa{#1}{%
      (\sls@headwidth,#2)%
      {%
        \makebox[\z@][l]{#6}\hfill
        \makebox[\z@][c]{#5}\hfill
        \makebox[\z@][r]{#4}%
      }{%
        \makebox[\z@][l]{#4}\hfill
        \makebox[\z@][c]{#5}\hfill
        \makebox[\z@][r]{#6}%
      }{%
        \makebox[\z@][l]{#4}\hfill
        \makebox[\z@][c]{#5}\hfill
        \makebox[\z@][r]{#6}%
      }%
      (\sls@headwidth,#3)%
    }{%
      (\sls@footwidth,#3)%
      {%
        \makebox[\z@][l]{#9}\hfill
        \makebox[\z@][c]{#8}\hfill
        \makebox[\z@][r]{#7}%
      }{%
        \makebox[\z@][l]{#7}\hfill
        \makebox[\z@][c]{#8}\hfill
        \makebox[\z@][r]{#9}%
      }{%
        \makebox[\z@][l]{#7}\hfill
        \makebox[\z@][c]{#8}\hfill
        \makebox[\z@][r]{#9}%
      }%
      (\sls@footwidth,#2)%
    }%
  }%
}
%    \end{macrocode}
% \end{macro}^^A \scrlayer@@@triplestyle
% \end{macro}^^A \scrlayer@@triplestyle
% \end{macro}^^A \scrlayer@triplestyle
%    \begin{macrocode}
\scrlayerAddToInterface{\deftripstyle}{%
  \newcommand*{\deftripstyle}{%
    \PackageWarning{scrlayer-scrpage}{%
      Command \string\deftripstyle\space is deprecate.\MessageBreak
      You should replace it by \string\deftriplepagestyle,\MessageBreak
      e.g.,%
    }%
    \let\deftripstyle\deftriplepagestyle
    \deftripstyle
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \deftripstyle
% \end{macro}^^A \providetriplepagestyle
% \end{macro}^^A \renewtriplepagestyle
% \end{macro}^^A \newtriplepagestyle
% \end{macro}^^A \deftriplepagestyle
%
%
% \section{Pre-defined Page Styles Interface}
%
% This is the high-level interface of \Package{scrpage2} with the page style
% \Pagestyle{scrheadings}, \Pagestyle{scrplain}, and
% \Pagestyle{useheadings}. Those will work as expected but will also be
% extended to support definition of additional styles using the same
% interface.
%
% \begin{macro}{\defpairofpagestyles}
%   \begin{description}
%   \item[\OParameter{string}:] name of a parent page style, that will be used
%     to initialise the new page style (must be fully expandable and expand to
%     the name of a page style).
%   \item[\Parameter{string}:] name the page style to be defined (must be
%     fully expandable and expand to the name of a page style).
%   \item[\Parameter{code}:] several commands of \Macro{ihead}, \Macro{chead},
%     \Macro{ohead}, \Macro{lehead}, \Macro{lohead}, \Macro{cohead},
%     \Macro{rehead}, \Macro{cehead}, \Macro{rohead}, \Macro{ifoot},
%     \Macro{cfoot}, \Macro{ofoot}, \Macro{lefoot}, \Macro{cefoot},
%     \Macro{lofoot}, \Macro{refoot}, \Macro{cofoot}, \Macro{rofoot},
%     \Macro{clearscrheadfoot}, \Macro{clearscrheadings},
%     \Macro{clearscrplain}.
%   \end{description}
% Two page styles will be defined using \Macro{defpagestyle}, page style named
% with the second argument and page style with the same name but an additional
% prefix ``\texttt{plain.}''. This will be activated automatically to be the
% plain page style when the first page style will be used. If first argument
% is used this pair of page styles will be used to initialise the head and
% footer of the new. All the other commands are used to define the initial
% fields. Note, if one of those page styles is active, all further commands
% (see 3rd argument) depend on the active page style. If no one is active,
% they depend on page style \texttt{scrheadings}.
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\defpairofpagestyles{%
  \newcommand*{\defpairofpagestyles}[3][]{%
    \def\reserved@a##1##2##3##4##5##6##7\@nil{##1##2##3##4##5##6}%
    \edef\reserved@a{\expandafter\reserved@a #2xxxxxx\@nil}%
    \ifstr\reserved@a{plain.}{%
      \PackageError{scrlayer-scrpage}{plain page style `#2' not allowed}{%
        You may not define a plain page style using
        \string\defpairofpagestyles, \string\newpairofpagestyles,
        \string\renewpairofpagestyles, or\MessageBreak
        \string\providepairofpagestyles.  I'd suggest to simply define the
        corresponding\MessageBreak
        non-plain page style to also define the plain one.\MessageBreak
        If you'll continue, your command will be ignored.}%
    }{%
      \sls@init@pair@page@style*{#2}%
      \sls@init@pair@page@style*{plain.#2}%
      \ifx\relax #1\relax\else
        \scr@ifundefinedorrelax{sls@ps@#1@even@left@head}{%
          \PackageError{scrlayer-scrpage}{`#1' not a pair page style}{%
            Only pair page styles may be used to initialise new pairs of page
            styles. So\MessageBreak
            optional argument of \string\defpairofpagestyles,
            \string\newpairofpagestyles,\MessageBreak
            \string\renewpairofpagestyles, or \string\providepairofpagestyle has
            to be a pair\MessageBreak
            page style or should be unused.\MessageBreak
            If you'll continue, the initialisation will be ignored.}%
        }{%
          \sls@init@pair@page@style{#2}{#1}%
          \scr@ifundefinedorrelax{sls@ps@plain.#1@even@left@head}{%
            \sls@init@pair@page@style{plain.#2}{#1}%
          }{%
            \sls@init@pair@page@style{plain.#2}{plain.#1}%
          }%
        }%
      \fi
      \edef\reserved@a{%
        \noexpand\scrlayerOnAutoRemoveInterface[scrlayer-scrpage.sty]{%
          \noexpand\sls@init@pair@page@style**{#2}%
          \noexpand\sls@init@pair@page@style**{plain.#2}%
          \noexpand\expandafter\noexpand\ifx\noexpand
          \csname ps@plain.#2\noexpand\endcsname\noexpand\ps@plain
          \noexpand\PackageWarning{scrlayer-scrpage}{%
            page style `#2' not longer valid.\noexpand\MessageBreak
            This was the current plain page style.\noexpand\MessageBreak
            Making current plain page style empty.\noexpand\MessageBreak
            The page style has been defined using\noexpand\MessageBreak
            interface `scrlayer-scrpage.sty', that\noexpand\MessageBreak
            has been removed%
          }%
          \noexpand\def\noexpand\ps@plain{%
            \noexpand\def\noexpand\@oddhead{}\noexpand\def\noexpand\@evenhead{}%
            \noexpand\def\noexpand\@oddhead{}\noexpand\def\noexpand\@evenhead{}%
          }%
          \noexpand\fi
        }%
      }\reserved@a
      \sls@def@pair@page@style@member{#2}%
      \AddToLayerPageStyleOptions{#2}{%
        onselect={%
%    \end{macrocode}
% \changes{v3.15}{2015/01/08}{usage of \cs{DeclarePageStyleAlias} instead of
% \cs{let}}^^A fixme: Is this correct?
%    \begin{macrocode}
          \DeclarePageStyleAlias{plain}{plain.#2}%
          \DeclarePageStyleAlias{headings}{#2}%
          \def\sls@currentheadings{#2}%
          \def\sls@currentplain{plain.#2}%
          #3%
        }%
      }%
      \sls@def@pair@page@style@member{plain.#2}%
      \AddToLayerPageStyleOptions{plain.#2}{%
        onselect={%
%    \end{macrocode}
% \changes{v3.15}{2015/01/08}{usage of \cs{DeclarePageStyleAlias} instead of
% \cs{let}}^^A fixme: Is this correct?
%    \begin{macrocode}
          \DeclarePageStyleAlias{plain}{plain.#2}%
          \DeclarePageStyleAlias{headings}{#2}%
          \def\sls@currentheadings{#2}%
          \def\sls@currentplain{plain.#2}%
          #3%
        },%
        oninit={%
          \expandafter
          \ifx\csname ifsls@plain@head@above@line\expandafter\endcsname
            \csname iftrue\endcsname\else
            \let\sls@headabove@linelength\z@
            \let\sls@headabove@linethickness\z@
          \fi
          \expandafter
          \ifx\csname ifsls@plain@head@below@line\expandafter\endcsname
              \csname iftrue\endcsname\else
            \let\sls@headbelow@linelength\z@
            \let\sls@headbelow@linethickness\z@
          \fi
          \expandafter
          \ifx\csname ifsls@plain@foot@above@line\expandafter\endcsname
              \csname iftrue\endcsname\else
            \let\sls@footabove@linelength\z@
            \let\sls@footabove@linethickness\z@
          \fi
          \expandafter
          \ifx\csname ifsls@plain@foot@below@line\expandafter\endcsname
              \csname iftrue\endcsname\else
            \let\sls@footbelow@linelength\z@
            \let\sls@footbelow@linethickness\z@
          \fi
        }%
      }%
    }%
  }%
}
%    \end{macrocode}
% \begin{macro}{\sls@currentheadings}
% \begin{macro}{\sls@currentplain}
% These little helpers will be set up at selection of each pair page style and
% stores the last activated page style pair of the scope.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@currentheadings{%
  \newcommand*\sls@currentheadings{scrheadings}%
}
\scrlayerAddToInterface\sls@currentplain{%
  \newcommand*\sls@currentplain{plain.scrheadings}%
}
%    \end{macrocode}
% \end{macro}^^A \sls@currentplain
% \end{macro}^^A \sls@currentheadings
% \begin{macro}{\sls@init@pair@page@style}
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\sls@init@@pair@page@style}
%   \begin{description}
%   \item[\Parameter{string}:] the name of the page style, that should be
%     initialised to be one member of a page style pair.
%   \item[\Parameter{string}:] the name of a member of a page style pair, that
%     should be used to initialise one the member of a page style pair from
%     first argument.
%   \end{description}
% These are two little helpers for \Macro{defpairofpagestyles}.
% The first command has two starred versions. With one star the commands for
% the page style will be initialised to \Macro{@empty}, with two stars they
% will become \LaTeX-undefined (\Macro{relax}).
%
% Note also, that the second argument may either be the plain or the non-plain
% member of the page style pair.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@init@pair@page@style{%
  \newcommand*{\sls@init@pair@page@style}{%
    \kernel@ifstar {%
      \kernel@ifstar {%
        \sls@let@pair@page@style\relax
      }{%
        \sls@let@pair@page@style\@empty
      }
    }{%
      \sls@init@@pair@page@style
    }%
  }%
}
\scrlayerAddToInterface\sls@init@@pair@page@style{%
  \newcommand*{\sls@init@@pair@page@style}[2]{%
    \expandafter\let\csname sls@ps@#1@even@left@head\expandafter\endcsname
    \csname sls@ps@#2@even@left@head\endcsname
    \expandafter\let\csname sls@ps@#1@even@middle@head\expandafter\endcsname
    \csname sls@ps@#2@even@middle@head\endcsname
    \expandafter\let\csname sls@ps@#1@even@right@head\expandafter\endcsname
    \csname sls@ps@#2@even@right@head\endcsname
    \expandafter\let\csname sls@ps@#1@odd@left@head\expandafter\endcsname
    \csname sls@ps@#2@odd@left@head\endcsname
    \expandafter\let\csname sls@ps@#1@odd@middle@head\expandafter\endcsname
    \csname sls@ps@#2@odd@middle@head\endcsname
    \expandafter\let\csname sls@ps@#1@odd@right@head\expandafter\endcsname
    \csname sls@ps@#2@odd@right@head\endcsname
    \expandafter\let\csname sls@ps@#1@even@left@foot\expandafter\endcsname
    \csname sls@ps@#2@even@left@foot\endcsname
    \expandafter\let\csname sls@ps@#1@even@middle@foot\expandafter\endcsname
    \csname sls@ps@#2@even@middle@foot\endcsname
    \expandafter\let\csname sls@ps@#1@even@right@foot\expandafter\endcsname
    \csname sls@ps@#2@even@right@foot\endcsname
    \expandafter\let\csname sls@ps@#1@odd@left@foot\expandafter\endcsname
    \csname sls@ps@#2@odd@left@foot\endcsname
    \expandafter\let\csname sls@ps@#1@odd@middle@foot\expandafter\endcsname
    \csname sls@ps@#2@odd@middle@foot\endcsname
    \expandafter\let\csname sls@ps@#1@odd@right@foot\expandafter\endcsname
    \csname sls@ps@#2@odd@right@foot\endcsname
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@init@@pair@page@style
% \begin{macro}{\sls@let@pair@page@style}
%   \begin{description}
%   \item[\Parameter{command}:] a single command used to initialise the
%     commands of the page style commands.
%   \item[\Parameter{string}:] the name of a member of a page style pair, that
%     should be used to initialise one the member of a page style pair from
%     first argument.
%   \end{description}
% A little helper for \Macro{sls@init@pair@page@style}.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@let@pair@page@style{%
  \newcommand*{\sls@let@pair@page@style}[2]{%
    \expandafter\let\csname sls@ps@#2@even@left@head\endcsname #1%
    \expandafter\let\csname sls@ps@#2@even@middle@head\endcsname #1%
    \expandafter\let\csname sls@ps@#2@even@right@head\endcsname #1%
    \expandafter\let\csname sls@ps@#2@odd@left@head\endcsname #1%
    \expandafter\let\csname sls@ps@#2@odd@middle@head\endcsname #1%
    \expandafter\let\csname sls@ps@#2@odd@right@head\endcsname #1%
    \expandafter\let\csname sls@ps@#2@even@left@foot\endcsname #1%
    \expandafter\let\csname sls@ps@#2@even@middle@foot\endcsname #1%
    \expandafter\let\csname sls@ps@#2@even@right@foot\endcsname #1%
    \expandafter\let\csname sls@ps@#2@odd@left@foot\endcsname #1%
    \expandafter\let\csname sls@ps@#2@odd@middle@foot\endcsname #1%
    \expandafter\let\csname sls@ps@#2@odd@right@foot\endcsname #1%
  }%
}
%    \end{macrocode}
% \end{macro}^^A \sls@let@pair@page@style
% \end{macro}^^A \sls@init@pair@page@style
% \begin{macro}{\sls@def@pair@page@style@member}
%   \begin{description}
%   \item[\Parameter{string}:] name of the page style to be defined.
%   \end{description}
% A little helper for \Macro{defpairofpagestyles}.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@def@pair@page@style@member{%
  \newcommand*{\sls@def@pair@page@style@member}[1]{%
    \defpagestyle{#1}{%
      {%
        \makebox[0pt][l]{\parbox{\sls@headwidth}{\raggedright
            \strut\@nameuse{sls@ps@#1@even@left@head}\strut}}%
        \parbox{\sls@headwidth}{\centering
          \strut\@nameuse{sls@ps@#1@even@middle@head}\strut}%
        \makebox[0pt][r]{\parbox{\sls@headwidth}{\raggedleft
            \strut\@nameuse{sls@ps@#1@even@right@head}\strut}}%
      }{%
        \makebox[0pt][l]{\parbox{\sls@headwidth}{\raggedright
            \strut\@nameuse{sls@ps@#1@odd@left@head}\strut}}%
        \parbox{\sls@headwidth}{\centering
          \strut\@nameuse{sls@ps@#1@odd@middle@head}\strut}%
        \makebox[0pt][r]{\parbox{\sls@headwidth}{\raggedleft
            \strut\@nameuse{sls@ps@#1@odd@right@head}\strut}}%
      }{%
        \makebox[0pt][l]{\parbox{\sls@headwidth}{\raggedright
            \strut\@nameuse{sls@ps@#1@odd@left@head}\strut}}%
        \parbox{\sls@headwidth}{\centering
          \strut\@nameuse{sls@ps@#1@odd@middle@head}\strut}%
        \makebox[0pt][r]{\parbox{\sls@headwidth}{\raggedleft
            \strut\@nameuse{sls@ps@#1@odd@right@head}\strut}}%
      }%
    }{%
      {%
        \makebox[0pt][l]{\parbox{\sls@footwidth}{\raggedright
            \strut\@nameuse{sls@ps@#1@even@left@foot}\strut}}%
        \parbox{\sls@footwidth}{\centering
          \strut\@nameuse{sls@ps@#1@even@middle@foot}\strut}%
        \makebox[0pt][r]{\parbox{\sls@footwidth}{\raggedleft
            \strut\@nameuse{sls@ps@#1@even@right@foot}\strut}}%
      }{%
        \makebox[0pt][l]{\parbox{\sls@footwidth}{\raggedright
            \strut\@nameuse{sls@ps@#1@odd@left@foot}\strut}}%
        \parbox{\sls@footwidth}{\centering
          \strut\@nameuse{sls@ps@#1@odd@middle@foot}\strut}%
        \makebox[0pt][r]{\parbox{\sls@footwidth}{\raggedleft
            \strut\@nameuse{sls@ps@#1@odd@right@foot}\strut}}%
      }{%
        \makebox[0pt][l]{\parbox{\sls@footwidth}{\raggedright
            \strut\@nameuse{sls@ps@#1@odd@left@foot}\strut}}%
        \parbox{\sls@footwidth}{\centering
          \strut\@nameuse{sls@ps@#1@odd@middle@foot}\strut}%
        \makebox[0pt][r]{\parbox{\sls@footwidth}{\raggedleft
            \strut\@nameuse{sls@ps@#1@odd@right@foot}\strut}}%
      }%
    }%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \sls@def@pair@page@style@member
% \end{macro}^^A \defpairofpagestyles
%
% \begin{macro}{\newpairofpagestyles}
% \begin{macro}{\renewpairofpagestyles}
% \begin{macro}{\providepairofpagestyles}
% See \Macro{defpairofpagestyles} for the arguments.
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\newpairofpagestyles{%
  \newcommand*{\newpairofpagestyles}[3][]{%
    \scr@ifundefinedorrelax{ps@#2}{%
      \@ifundefined{ps@plain.#2}{\defpairofpagestyles[#1]{#2}{#3}}{%
        \PackageError{scrlayer-scrpage}{%
          Plain page style of `#2' already defined}{%
          You may only define a new pair of page styles, if neither the style
          itself\MessageBreak
          nor it's plain page style has already been defined.\MessageBreak
          You may use only \string\defpairofpagestyles\space or
          \string\providepairofpagestyles\space with partly\MessageBreak
          already defined page styles.\MessageBreak
          If you'll continue, your command will be ignored.%
        }%
      }%
    }{%
      \PackageError{scrlayer-scrpage}{%
        Page style `#2' already defined}{%
        You may only define a new pair of page styles, if neither the style
        itself\MessageBreak
        nor it's plain page style has already been defined.\MessageBreak
        You may use either \string\renewpairsofpagestyles,
        \string\defpairofpagestyles, or\MessageBreak
        \string\providepairofpagestyles\space with already defined page
        styles.\MessageBreak
        If you'll continue, your command will be ignored.%
      }%
    }%
  }%
}
\scrlayerAddToInterface\renewpairofpagestyles{%
  \newcommand*{\renewpairofpagestyles}[3][]{%
    \scr@ifundefinedorrelax{ps@#2}{%
      \PackageError{scrlayer-scrpage}{%
        Undefined page style `#2'}{%
        You may only redefine existing pairs of page styles. You may use
        either\MessageBreak
        \string\newpairsofpagestyles, \string\defpairofpagestyles, or
        \string\providepairofpagestyles\MessageBreak
        with not yet defined page styles.\MessageBreak
        If you'll continue, your command will be ignored.%
      }%
    }{%
      \@ifundefined{ps@plain.#2}{%
        \PackageError{scrlayer-scrpage}{%
          Undefined plain page style of `#2'}{%
          You may only redefine existing pairs of page styles. You may use
          either\MessageBreak
          \string\defpairofpagestyles\space or
          \string\providepairofpagestyles\space with partly already
          defined\MessageBreak
          page styles.\MessageBreak
          If you'll continue, your command will be ignored.%
        }%
      }{\defpairofpagestyles[#1]{#2}{#3}}%
    }%
  }%
}
\scrlayerAddToInterface\providepairofpagestyles{%
  \newcommand*{\providepairofpagestyles}[3][]{%
    \scr@ifundefinedorrelax{ps@#2}{%
      \@ifundefined{ps@plain.#2}{\defpairofpagestyles[#1]{#2}{#3}}{%
%<*trace>
        \PackageInfo{scrlayer-scrpage}{%
          Plain page style of `#2' already\MessageBreak
          defined. Definition ignored}%
%</trace>
      }%
    }{%
%<*trace>
      \PackageInfo{scrlayer-scrpage}{%
        Page style of `#2' already defined.\MessageBreak
        Definition ignored}%
%</trace>
    }%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \providepairofpagestyles
% \end{macro}^^A \renewpairofpagestyles
% \end{macro}^^A \newpairofpagestyles
%
% \begin{macro}{\ps@scrheadings}
% \begin{macro}{\ps@plain.scrheadings}
% We have one predefined pair: \texttt{scrheadings} with plain page style
% \texttt{plain.scrheadings}.
%    \begin{macrocode}
%<*body>
\newpairofpagestyles{scrheadings}{}%
%    \end{macrocode}
% \begin{macro}{\ps@scrplain}
% But with package \Package{scrpage2} the plain page style was
% \texttt{scrplain}. So we make a kind of alias:
%    \begin{macrocode}
\DeclarePageStyleAlias{scrplain}{plain.scrheadings}
\scrlayerOnAutoRemoveInterface{\DestroyPageStyleAlias{scrplain}}
%</body>
%    \end{macrocode}
% \end{macro}^^A \ps@scrplain
% \end{macro}^^A \ps@plain.scrheadings
% \end{macro}^^A \ps@scrheadings
%
%
% \begin{macro}{\ihead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\ohead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\chead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\lehead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\lohead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\rehead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\rohead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\cehead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\cohead}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\ifoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\ofoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\cfoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\lefoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\lofoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\refoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\rofoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\cefoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\cofoot}
%   \changes{v3.14}{2014/09/19}{new star version double the argument}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% We also need macros to define the contents of the three part head
% and foot. Each macro defines one of the part of head or foot of the
% headings page style member and optional of the plain page style
% member.
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\ihead{%
  \newcommand*{\ihead}{\kernel@ifstar {\@dblarg\@@@ihead}{\@ihead}}%
}
%    \end{macrocode}
% \begin{macro}{\@ihead}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\@@ihead}
% \begin{macro}{\@@@ihead}
% Two helpers for the previous one to double the command and it's arguments.
%    \begin{macrocode}
\scrlayerAddToInterface\@ihead{%
  \newcommand*{\@ihead}{\kernel@ifnextchar[{\@@@ihead}{\@@ihead}}%
}
\scrlayerAddToInterface\@@ihead{%
  \newcommand*{\@@ihead}[1]{\rehead{#1}\lohead{#1}}%
}
\scrlayerAddToInterface\@@@ihead{%
  \newcommand*{\@@@ihead}[2][]{\rehead[{#1}]{#2}\lohead[{#1}]{#2}}%
}
%    \end{macrocode}
% \end{macro}^^A \@@@ihead
% \end{macro}^^A \@@ihead
% \end{macro}^^A \@ihead
%    \begin{macrocode}
\scrlayerAddToInterface\ohead{%
  \newcommand*{\ohead}{\kernel@ifstar {\@dblarg\@@@ohead}{\@ohead}}%
}
%    \end{macrocode}
% \begin{macro}{\@ohead}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\@@ohead}
% \begin{macro}{\@@@ohead}
% Two helpers for the previous one to double the command and it's arguments.
%    \begin{macrocode}
\scrlayerAddToInterface\@ohead{%
  \newcommand*{\@ohead}{\kernel@ifnextchar[{\@@@ohead}{\@@ohead}}%
}
\scrlayerAddToInterface\@@ohead{%
  \newcommand*{\@@ohead}[1]{\lehead{#1}\rohead{#1}}%
}
\scrlayerAddToInterface\@@@ohead{%
  \newcommand*{\@@@ohead}[2][]{\lehead[{#1}]{#2}\rohead[{#1}]{#2}}%
}
%    \end{macrocode}
% \end{macro}^^A \@@@ohead
% \end{macro}^^A \@@ohead
% \end{macro}^^A \@ohead
%    \begin{macrocode}
\scrlayerAddToInterface\chead{%
  \newcommand*{\chead}{\kernel@ifstar {\@dblarg\@@@chead}{\@chead}}%
}
%    \end{macrocode}
% \begin{macro}{\@chead}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\@@chead}
% \begin{macro}{\@@@chead}
% Two helpers for the previous one to double the command and it's arguments.
%    \begin{macrocode}
\scrlayerAddToInterface\@chead{%
  \newcommand*{\@chead}{\kernel@ifnextchar[{\@@@chead}{\@@chead}}%
}
\scrlayerAddToInterface\@@chead{%
  \newcommand*{\@@chead}[1]{\cehead{#1}\cohead{#1}}%
}
\scrlayerAddToInterface\@@@chead{%
  \newcommand*{\@@@chead}[2][]{\cehead[{#1}]{#2}\cohead[{#1}]{#2}}%
}
%    \end{macrocode}
% \end{macro}^^A \@@@chead
% \end{macro}^^A \@@chead
% \end{macro}^^A \@chead
%    \begin{macrocode}
\scrlayerAddToInterface\lehead{%
  \newcommand*{\lehead}{\sls@renewelement{even}{left}{head}}%
}
\scrlayerAddToInterface\lohead{%
  \newcommand*{\lohead}{\sls@renewelement{odd}{left}{head}}%
}
\scrlayerAddToInterface\rehead{%
  \newcommand*{\rehead}{\sls@renewelement{even}{right}{head}}%
}
\scrlayerAddToInterface\rohead{%
  \newcommand*{\rohead}{\sls@renewelement{odd}{right}{head}}%
}
\scrlayerAddToInterface\cehead{%
  \newcommand*{\cehead}{\sls@renewelement{even}{middle}{head}}%
}
\scrlayerAddToInterface\cohead{%
  \newcommand*{\cohead}{\sls@renewelement{odd}{middle}{head}}%
}
%    \end{macrocode}
%    \begin{macrocode}
\scrlayerAddToInterface\ifoot{%
  \newcommand*{\ifoot}{\kernel@ifstar {\@dblarg\@@@ifoot}{\@ifoot}}%
}
%    \end{macrocode}
% \begin{macro}{\@ifoot}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\@@ifoot}
% \begin{macro}{\@@@ifoot}
% Two helpers for the previous one to double the command and it's arguments.
%    \begin{macrocode}
\scrlayerAddToInterface\@ifoot{%
  \newcommand*{\@ifoot}{\kernel@ifnextchar[{\@@@ifoot}{\@@ifoot}}%
}
\scrlayerAddToInterface\@@ifoot{%
  \newcommand*{\@@ifoot}[1]{\refoot{#1}\lofoot{#1}}%
}
\scrlayerAddToInterface\@@@ifoot{%
  \newcommand*{\@@@ifoot}[2][]{\refoot[{#1}]{#2}\lofoot[{#1}]{#2}}%
}
%    \end{macrocode}
% \end{macro}^^A \@@@ifoot
% \end{macro}^^A \@@ifoot
% \end{macro}^^A \@ifoot
%    \begin{macrocode}
\scrlayerAddToInterface\ofoot{%
  \newcommand*{\ofoot}{\kernel@ifstar {\@dblarg\@@@ofoot}{\@ofoot}}%
}
%    \end{macrocode}
% \begin{macro}{\@ofoot}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\@@ofoot}
% \begin{macro}{\@@@ofoot}
% Two helpers for the previous one to double the command and it's arguments.
%    \begin{macrocode}
\scrlayerAddToInterface\@ofoot{%
  \newcommand*{\@ofoot}{\kernel@ifnextchar[{\@@@ofoot}{\@@ofoot}}%
}
\scrlayerAddToInterface\@@ofoot{%
  \newcommand*{\@@ofoot}[1]{\lefoot{#1}\rofoot{#1}}%
}
\scrlayerAddToInterface\@@@ofoot{%
  \newcommand*{\@@@ofoot}[2][]{\lefoot[{#1}]{#2}\rofoot[{#1}]{#2}}%
}
%    \end{macrocode}
% \end{macro}^^A \@@@ofoot
% \end{macro}^^A \@@ofoot
% \end{macro}^^A \@ofoot
%    \begin{macrocode}
\scrlayerAddToInterface\cfoot{%
  \newcommand*{\cfoot}{\kernel@ifstar {\@dblarg\@@@cfoot}{\@cfoot}}%
}
%    \end{macrocode}
% \begin{macro}{\@cfoot}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
% \begin{macro}{\@@cfoot}
% \begin{macro}{\@@@cfoot}
% Two helpers for the previous one to double the command and it's arguments.
%    \begin{macrocode}
\scrlayerAddToInterface\@cfoot{%
  \newcommand*{\@cfoot}{\kernel@ifnextchar[{\@@@cfoot}{\@@cfoot}}%
}
\scrlayerAddToInterface\@@cfoot{%
  \newcommand*{\@@cfoot}[1]{\cefoot{#1}\cofoot{#1}}%
}
\scrlayerAddToInterface\@@@cfoot{%
  \newcommand*{\@@@cfoot}[2][]{\cefoot[{#1}]{#2}\cofoot[{#1}]{#2}}%
}
%    \end{macrocode}
% \end{macro}^^A \@@@cfoot
% \end{macro}^^A \@@cfoot
% \end{macro}^^A \@cfoot
%    \begin{macrocode}
\scrlayerAddToInterface\lefoot{%
  \newcommand*{\lefoot}{\sls@renewelement{even}{left}{foot}}%
}
\scrlayerAddToInterface\lofoot{%
  \newcommand*{\lofoot}{\sls@renewelement{odd}{left}{foot}}%
}
\scrlayerAddToInterface\refoot{%
  \newcommand*{\refoot}{\sls@renewelement{even}{right}{foot}}%
}
\scrlayerAddToInterface\rofoot{%
  \newcommand*{\rofoot}{\sls@renewelement{odd}{right}{foot}}%
}
\scrlayerAddToInterface\cefoot{%
  \newcommand*{\cefoot}{\sls@renewelement{even}{middle}{foot}}%
}
\scrlayerAddToInterface\cofoot{%
  \newcommand*{\cofoot}{\sls@renewelement{odd}{middle}{foot}}%
}
%    \end{macrocode}
% \begin{macro}{\sls@renewelement}
% \begin{macro}{\sls@@renewelement}
%   \changes{v3.20}{2016/04/12}{\cs{@ifnextchar} replaced by
%     \cs{kernel@ifnextchar}}^^A
%   \changes{v3.20}{2016/04/12}{\cs{@ifstar} durch \cs{kernel@ifstar}
%     ersetzt}^^A
% \begin{macro}{\sls@@@renewelement}
% \begin{macro}{\sls@@@@renewelement}
% \begin{macro}{\sls@@renewplainelement}
% Little helper for several of the above commands.
%    \begin{macrocode}
\scrlayerAddToInterface\sls@renewelement{%
  \newcommand*{\sls@renewelement}[3]{%
    \kernel@ifstar{\@dblarg{\sls@@@@renewelement{#1}{#2}{#3}}}%
                  {\sls@@renewelement{#1}{#2}{#3}}%
  }%
}
\scrlayerAddToInterface\sls@@renewelement{%
  \newcommand*{\sls@@renewelement}[3]{%
    \kernel@ifnextchar[%]
    {\sls@@@@renewelement{#1}{#2}{#3}}%
    {\sls@@@renewelement{#1}{#2}{#3}}%
  }%
}
\scrlayerAddToInterface\sls@@@renewelement{%
  \newcommand*{\sls@@@renewelement}[4]{%
    \scr@ifundefinedorrelax{sls@ps@\sls@currentheadings @#1@#2@#3}{%
      \@namedef{sls@ps@scrheadings@#1@#2@#3}{#4}%
    }{%
      \@namedef{sls@ps@\sls@currentheadings @#1@#2@#3}{#4}%
    }%
  }%
}
\scrlayerAddToInterface\sls@@@@renewelement{%
  \def\sls@@@@renewelement#1#2#3[#4]#5{%
    \sls@@renewplainelement{#1}{#2}{#3}{#4}%
    \sls@@@renewelement{#1}{#2}{#3}{#5}%
  }%
}
\scrlayerAddToInterface\sls@@renewplainelement{%
  \newcommand*{\sls@@renewplainelement}[4]{%
    \scr@ifundefinedorrelax{sls@ps@\sls@currentplain @#1@#2@#3}{%
      \@namedef{sls@ps@plain.scrheadings@#1@#2@#3}{#4}%
    }{%
      \@namedef{sls@ps@\sls@currentplain @#1@#2@#3}{#4}%
    }%
  }%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \sls@@renewplainelement
% \end{macro}^^A \sls@@@@renewelement
% \end{macro}^^A \sls@@@renewelement
% \end{macro}^^A \sls@@renewelement
% \end{macro}^^A \sls@renewelement
% \end{macro}^^A \cofoot
% \end{macro}^^A \cefoot
% \end{macro}^^A \rofoot
% \end{macro}^^A \refoot
% \end{macro}^^A \lofoot
% \end{macro}^^A \lefoot
% \end{macro}^^A \cfoot
% \end{macro}^^A \ofoot
% \end{macro}^^A \ifoot
% \end{macro}^^A \cohead
% \end{macro}^^A \cehead
% \end{macro}^^A \rohead
% \end{macro}^^A \rehead
% \end{macro}^^A \lohead
% \end{macro}^^A \lehead
% \end{macro}^^A \chead
% \end{macro}^^A \ohead
% \end{macro}^^A \ihead
%
% \begin{macro}{\clearmainofpairofpagestyles}
% \begin{macro}{\clearscrheadings}
% Maybe you want to clear the currently defined head and foot. First
% let's clear only scrheadings pagestyle but not scrplain pagestyle.
% We do this simply using the already known command:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\clearmainofpairofpagestyles{%
  \newcommand*{\clearmainofpairofpagestyles}{%
    \ihead{}\chead{}\ohead{}\ifoot{}\cfoot{}\ofoot{}%
  }%
}
\scrlayerAddToInterface\clearscrheadings{%
  \let\clearscrheadings\clearmainofpairofpagestyles
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \clearscrheadings
% \end{macro}^^A \clearmainofpairofpagestyles
% \begin{macro}{\clearplainofpairofpagestyles}
% \begin{macro}{\clearscrplain}
% Now, we use the not recommended feature to set up a plain style:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\clearplainofpairofpagestyles{%
  \newcommand*{\clearplainofpairofpagestyles}{%
    \sls@@renewplainelement{odd}{left}{head}{}%
    \sls@@renewplainelement{odd}{right}{head}{}%
    \sls@@renewplainelement{odd}{middle}{head}{}%
    \sls@@renewplainelement{even}{left}{head}{}%
    \sls@@renewplainelement{even}{right}{head}{}%
    \sls@@renewplainelement{even}{middle}{head}{}%
    \sls@@renewplainelement{odd}{left}{foot}{}%
    \sls@@renewplainelement{odd}{right}{foot}{}%
    \sls@@renewplainelement{odd}{middle}{foot}{}%
    \sls@@renewplainelement{even}{left}{foot}{}%
    \sls@@renewplainelement{even}{right}{foot}{}%
    \sls@@renewplainelement{even}{middle}{foot}{}%
  }%
}
\scrlayerAddToInterface\clearscrplain{%
  \let\clearscrplain\clearplainofpairofpagestyles
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \clearscrplain
% \end{macro}^^A \clearplainofpairofpagestyles
% \begin{macro}{\clearpairofpagestyles}
% \begin{macro}{\clearscrheadfoot}
% Last but not least we clean up both, the main and the plain:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\clearpairofpagestyles{%
  \newcommand*{\clearpairofpagestyles}{%
    \ihead[]{}\chead[]{}\ohead[]{}\ifoot[]{}\cfoot[]{}\ofoot[]{}%
  }%
}
\scrlayerAddToInterface\clearscrheadfoot{%
  \let\clearscrheadfoot\clearpairofpagestyles
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \clearscrheadfoot
% \end{macro}^^A \clearpairofpagestyles
%
% \begin{macro}{\ps@useheadings}
% Not longer supported:
%    \begin{macrocode}
%<*body>
\scrlayerAddToInterface\ps@useheadings{%
  \newcommand*\ps@useheadings{%
    \PackageWarning{scrlayer-scrpage}{incompatible page style!\MessageBreak
      Page styles like `headings' and `plain'\MessageBreak
      are incompatible with the page styles\MessageBreak
      of scrlayer-scrpage. You shouldn't mix\MessageBreak
      them up. Therefore page style\MessageBreak
      `useheadings' is not longer provided.\MessageBreak
      Usage is deprecated and will be replaced\MessageBreak
      by `scrheadings'%
    }%
    \let\ps@useheadings\ps@scrheadings
    \ps@useheadings
  }%
}
\scrlayerAddCsToInterface{ps@plain.useheadings}{%
  \@namedef{ps@plain.useheadings}{\@nameuse{ps@plain.scrheadings}}%
}
%</body>
%    \end{macrocode}
% \end{macro}^^A \ps@useheadings
%
% \iffalse^^A meta-comment
%</interface>
% \fi^^A meta-comment
%
% \Finale
% \let\subsection\section
% \let\section\chapter
% \let\chapter\restorechapter
%
\endinput
%
% end of file `scrlayer.dtx'

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