ieee.bbx

%% ---------------------------------------------------------------
%% biblatex-ieee --- A biblatex implementation of the IEEE
%%   bibliography style
%% Maintained by Joseph Wright
%% E-mail: joseph.wright@morningstar2.co.uk
%% Released under the LaTeX Project Public License v1.3c or later
%% See http://www.latex-project.org/lppl.txt
%% ---------------------------------------------------------------
%%

\ProvidesFile{ieee.bbx}[2019/06/19 v1.3a biblatex bibliography style]

% Load the standard style to avoid copy-pasting unnecessary material
\RequireBibliographyStyle{numeric-comp}

% An option that carries through from author-year styles
\DeclareBibliographyOption[boolean]{dashed}[true]{%
  \ifstrequal{#1}{true}
    {\ExecuteBibliographyOptions{pagetracker}%
     \renewbibmacro*{bbx:savehash}{\savefield{fullhash}{\bbx@lasthash}}}
    {\renewbibmacro*{bbx:savehash}{}}}

% Alter settings that carry through from biblatex
\ExecuteBibliographyOptions{
  giveninits,
  maxnames = 999,
  minnames = 3,
  sorting  = none
}
\uspunctuation

% Load language-specific customizations
%\DeclareLanguageMapping{magyar}{magyar-ieee}
% If more language-specific customizations besides magyar should get
% added, the above explicit mapping per language can be replaced with:
% \DeclareLanguageMappingSuffix{-ieee}

% Custom field formats
\DeclareFieldFormat[article]{number}{\bibstring{number}\addnbspace#1}
\DeclareFieldFormat[patent]{number}{\mkonepagegrouped{#1}}
\DeclareFieldFormat{pages}{%
  \mkpageprefix[bookpagination][\mkpagegrouped]{#1}%
}
\DeclareFieldFormat{sentencecase}{\bbx@colon@search{\MakeSentenceCase*}{#1}}
\DeclareFieldFormat[book,inbook,incollection,inproceedings]{series}
  {\bibstring{jourser}\addnbspace#1}
\DeclareFieldFormat[online]{title}{#1\isdot}
\DeclareFieldFormat[report]{title}{\mkbibquote{#1\isdot}}
\DeclareFieldFormat{url}{\bibstring{url}\addcolon\space\url{#1}}
\DeclareFieldFormat*{volume}
  {\bibstring{volume}\addnbspace#1}
\DeclareFieldFormat[article,periodical]{volume}
  {\bibstring{jourvol}\addnbspace#1}

% Simple modifications to punctuation, etc.
\renewcommand*\bibnamedash{\textemdash\textemdash}
\renewcommand*\intitlepunct{\addspace}
\renewcommand*\newunitpunct{\addcomma\addspace}

% Bibliography strings
\NewBibliographyString{patentjp}
\NewBibliographyString{presentedat}

\DefineBibliographyStrings{english}{
  andothers   = \mkbibemph{et al\adddot}           ,
  chapter     = ch\adddot                          ,
  editor      = Ed\adddot                          ,
  editors     = Eds\adddot                         ,
  mathesis    = Master's thesis                    ,
  patentjp    = Japanese Patent                    ,
  patentus    = U\adddot S\adddot\addspace Patent  ,
  presentedat = presented at the\addspace          ,
  techreport  = Tech\adddot\addspace Rep\adddot    ,
  url         = [Online]\adddot\addspace Available ,
}

\DefineBibliographyStrings{english}{
  june      = Jun\adddot ,
  july      = Jul\adddot ,
  september = Sep\adddot ,
}

% Support for dashed author name replacement
\InitializeBibliographyStyle{\global\undef\bbx@lasthash}

\newbibmacro*{bbx:savehash}{\savefield{fullhash}{\bbx@lasthash}}

% Bibliography macros
\renewbibmacro*{author}{%
  \ifboolexpr{
    test \ifuseauthor
    and
    not test {\ifnameundef{author}}
  }
    {%
      \iffieldequals{fullhash}{\bbx@lasthash}
        {\bibnamedash\addcomma\space}
        {\printnames{author}}%
      \usebibmacro{bbx:savehash}%
      \iffieldundef{authortype}
        {}
        {%
          \setunit{\addcomma\space}%
          \usebibmacro{authorstrg}%
        }%
    }
    {\global\undef\bbx@lasthash}%
}

\renewbibmacro*{bybookauthor}{%
  \ifnamesequal{author}{bookauthor}
    {}
    {%
      \iffieldundef{bookauthor}
        {}
        {%
          \printnames{bookauthor}%
          \newunit
       }%
    }%
}

\renewbibmacro*{byeditor+others}{%
  \ifnameundef{editor}
    {}
    {%
      \usebibmacro{editor}%
      \setunit{\addspace}%
      \printnames[byeditor]{editor}%
      \clearname{editor}%
      \newunit
    }%
  \usebibmacro{byeditorx}%
  \usebibmacro{bytranslator+others}%
}

\renewbibmacro*{doi+eprint+url}{%
  \setunit{\adddot\addspace}%
  \iftoggle{bbx:doi}
    {\printfield{doi}}
    {}%
  \setunit{\adddot\addspace}%
  %\iftoggle{bbx:eprint}
  %  {\usebibmacro{eprint}}
  %  {}%
  %\setunit{\adddot\addspace}%
  %\iftoggle{bbx:url}
  %  {\usebibmacro{url+urldate}}
  %  {}%
}

\renewbibmacro*{event+venue+date}{%
  \iffieldundef{eventtitle}
    {}
    {%
      \bibstring{presentedat}%
      \printfield{eventtitle}%
    }%
  \ifboolexpr{
    test {\iffieldundef{venue}}
    and
    test {\iffieldundef{eventyear}}
  }
    {}
    {\setunit*{\addspace}%
     \printtext[parens]{%
       \printfield{venue}%
       \setunit*{\addcomma\space}%
       \printeventdate}}%
  \newunit
}

\newbibmacro*{institution+location}{%
  \printlist{institution}%
  \newunit
  \printlist{location}%
  \newunit
}

\renewbibmacro*{institution+location+date}{%
  \printlist{institution}%
  \newunit
  \printlist{location}%
  \newunit
  \usebibmacro{date}%
  \newunit
}

\renewbibmacro*{issue+date}{%
  \printtext{%
    \iffieldundef{issue}
      {\usebibmacro{date}}
      {%
        \printfield{issue}%
        \setunit*{\addspace}%
        \usebibmacro{date}%
      }%
  }%
  \newunit
  \usebibmacro{issue}%
  \newunit
}

\renewbibmacro*{journal}{%
  \iffieldundef{journaltitle}
    {}
    {%
      \printtext[journaltitle]{%
         \printfield[titlecase]{journaltitle}%
         \printfield[titlecase]{journalsubtitle}%
      }%
    }%
  \midsentence
}

\renewbibmacro*{journal+issuetitle}{%
  \usebibmacro{journal}%
  \newunit
  \iffieldundef{series}
    {}
    {%
      \newunit
      \printfield{series}%
      \newunit
    }%
  \usebibmacro{volume+number+eid}%
  \setunit{\addspace}%
}

\renewbibmacro*{maintitle+booktitle}{%
  \iffieldundef{maintitle}
    {}
    {%
      \usebibmacro{maintitle}%
      \newunit\newblock
    }%
  \usebibmacro{booktitle}%
  \newunit
}

\newbibmacro*{maintitle+booktitle(inproceedings)}{%
  \iffieldundef{maintitle}
    {%
      \iffieldundef{booktitle}
        {}
        {%
          \usebibmacro{in:}%
          \usebibmacro{maintitle+booktitle}%
          \clearfield{eventtitle}%
          \clearfield{number}%
        }%
    }
    {%
      \usebibmacro{in:}%
      \usebibmacro{maintitle+booktitle}%
      \clearfield{eventtitle}%
      \clearfield{number}%
    }%
}

\renewbibmacro*{maintitle+title}{%
  \iffieldsequal{maintitle}{title}
    {%
      \clearfield{maintitle}%
      \clearfield{mainsubtitle}%
      \clearfield{maintitleaddon}%
    }
    {%
      \iffieldundef{maintitle}
        {}
        {%
          \usebibmacro{maintitle}%
          \newunit\newblock
        }%
    }%
  \usebibmacro{title-in-maintitle}%
  \newunit
}

\newbibmacro*{pages}{%
  \setunit{\bibpagespunct}%
  \printfield{pages}%
}

\renewbibmacro*{title}{%
  \ifboolexpr{
    test {\iffieldundef{title}}
    and
    test {\iffieldundef{subtitle}}
  }
    {}
    {%
      \printtext[title]{%
        \printfield[sentencecase]{title}%
        \setunit{\subtitlepunct}%
        \printfield[sentencecase]{subtitle}%
      }%
      \newunit
    }%
  \printfield{titleaddon}%
}

\newbibmacro*{title-in-maintitle}{%
  \ifboolexpr{
    test {\iffieldundef{title}}
    and
    test {\iffieldundef{subtitle}}
  }
    {}
    {%
      \printtext[title]{%
        \printfield[titlecase]{title}%
        \setunit{\subtitlepunct}%
        \printfield[titlecase]{subtitle}%
      }%
      \newunit
    }%
  \printfield{titleaddon}%
}

\renewbibmacro*{volume+number+eid}{%
  \printfield{volume}%
  \newunit
  \printfield{number}%
  \newunit
  \printfield{eid}%
}

\newbibmacro*{volume+part}{%
  \iffieldundef{volume}
    {}
    {%
      \printfield{volume}%
      \printfield{part}%
      \setunit{\addcolon\space}%
    }%
}

% Specialised functions for manipulating data, where the biblatex
% kernel does not provide a suitable function.
\newcommand*{\mkpagegrouped}[1]{%
  \mkpagegrouped@aux#1\bibrangedash&%
}

\newcommand*{\mkpagegrouped@aux}{}
\def\mkpagegrouped@aux#1\bibrangedash#2&{%
  \mkonepagegrouped{#1}%
  \ifblank{#2}
    {}
    {%
      \bibrangedash
      \mkpagegrouped@second#2&%
    }%
}

\newcommand*{\mkonepagegrouped}[1]{%
  \ifinteger{#1}
    {%
      \mkpagegrouped@ifmorethanfour{#1}
        {\mkpagegrouped@separate{}#1\@empty\@empty\@empty}
        {#1}%
     }
     {#1}%
}

\newcommand*{\mkpagegrouped@second}{}
\def\mkpagegrouped@second#1\bibrangedash&{%
  \mkpagegrouped@second@auxi#1\bibrangessep&%
}

\newcommand*{\mkpagegrouped@second@auxi}{}
\def\mkpagegrouped@second@auxi#1\bibrangessep#2&{%
   \mkonepagegrouped{#1}%
   \ifblank{#2}
     {}
     {%
       \bibrangessep
       \mkpagegrouped@second@auxii#2&%
     }%
}

\newcommand*{\mkpagegrouped@second@auxii}{}
\def\mkpagegrouped@second@auxii#1\bibrangessep&{%
  \mkpagegrouped{#1}%
}

\newcommand*{\mkpagegrouped@ifmorethanfour}[1]{%
  \mkpagegrouped@ifmorethanfour@aux#1\@empty\@empty\@empty\@empty
    \@empty\@nil
}

\newcommand*{\mkpagegrouped@ifmorethanfour@aux}{}
\def\mkpagegrouped@ifmorethanfour@aux#1#2#3#4#5\@nil{%
 \ifx\@empty#5\@empty
   \expandafter\@secondoftwo
  \else
    \expandafter\@firstoftwo
  \fi
}

\newcommand*{\mkpagegrouped@separate}[4]{%
  \ifx\@empty#2\@empty
    \mkpagegrouped@print#1\relax
  \else
    \ifx\@empty#3\@empty
      \mkpagegrouped@print\@empty\@empty#1#2\relax
    \else
      \ifx\@empty#4\@empty
        \mkpagegrouped@print\@empty#1#2#3\relax
      \else
        \mkpagegrouped@separate@aux{#1#2#3#4}%
      \fi
    \fi
  \fi
}

\newcommand*{\bbx@digits@separate@aux}{}
\def\mkpagegrouped@separate@aux#1\fi\fi\fi{%
  \fi\fi\fi\mkpagegrouped@separate{#1}%
}

\newcommand*{\mkpagegrouped@print}[4]{%
  \ifblank{#1}{}{#1}%
  #2#3%
  \ifx#4\relax
  \else
    \addnbthinspace
    \expandafter\mkpagegrouped@print\expandafter#4%
  \fi
}

% {<process>} {<text>}
\newcommand*{\bbx@colon@search}[2]{%
  \bbx@colon@search@auxi\empty#2: \stop{#1}%
}
\long\def\bbx@colon@search@auxi#1: #2\stop#3{%
  \expandafter\bbx@colon@search@auxii\expandafter{#1}{#3}%
  \ifblank{#2}
    {}
    {%
      : %
      \bbx@colon@search@auxi\empty#2\stop{#3}%
    }%
}
\newcommand\bbx@colon@search@auxii[2]{#2{#1}}

% New bibliography drivers, using the required order of fields. These
% are mainly copied from standard.bbx then modified.
\DeclareBibliographyDriver{article}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/translator+others}%
  \newunit
  \usebibmacro{title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \usebibmacro{bytranslator+others}%
  \newunit\newblock
  \printfield{version}%
  \newunit\newblock
  \usebibmacro{journal+issuetitle}%
  \newunit
  \usebibmacro{byeditor+others}%
  \newunit
  \usebibmacro{pages}%
  \newunit
  \usebibmacro{issue+date}%
  \newunit
  \printfield{note}%
  \newunit\newblock
  %\iftoggle{bbx:isbn}
  %  {\printfield{issn}}
  %  {}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{book}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/editor+others/translator+others}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{maintitle+title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \printfield{edition}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \usebibmacro{byeditor+others}%
  \newunit\newblock
  \printfield{volumes}%
  \newunit\newblock
  \usebibmacro{series+number}%
  \setunit{\adddot\addspace}%
  \newblock
  \usebibmacro{publisher+location+date}%
  \newunit\newblock
  \usebibmacro{volume+part}%
  \newunit
  \usebibmacro{chapter+pages}%
  \newunit
  \printfield{pagetotal}%
  \newunit\newblock
  \printfield{note}%
  \newunit\newblock
  %\iftoggle{bbx:isbn}
  %  {\printfield{isbn}}
  %  {}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{inbook}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/translator+others}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \usebibmacro{in:}%
  \usebibmacro{bybookauthor}%
  \usebibmacro{maintitle+booktitle}%
  \newunit\newblock
  \usebibmacro{byeditor+others}%
  \newunit\newblock
  \printfield{edition}%
  \newunit
  \printfield{volumes}%
  \newunit\newblock
  \usebibmacro{series+number}%
  \setunit{\adddot\addspace}%
  \newblock
  \usebibmacro{publisher+location+date}%
  \newunit\newblock
  \usebibmacro{volume+part}%
  \newunit
  \usebibmacro{chapter+pages}%
  \newunit\newblock
  \printfield{note}%
  \newunit\newblock
 % \iftoggle{bbx:isbn}
  %  {\printfield{isbn}}
 %   {}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{incollection}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/translator+others}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \usebibmacro{in:}%
  \usebibmacro{maintitle+booktitle}%
  \newunit\newblock
  \usebibmacro{series+number}%
  \newunit\newblock
  \usebibmacro{byeditor+others}%
  \newunit\newblock
  \printfield{edition}%
  \newunit
  \iffieldundef{maintitle}
    {\printfield{volume}%
     \printfield{part}}
    {}%
  \newunit
  \printfield{volumes}%
  \newunit\newblock
  \printfield{note}%
  \newunit\newblock
  \usebibmacro{publisher+location+date}%
  \newunit\newblock
  \usebibmacro{chapter+pages}%
  \newunit\newblock
  %\iftoggle{bbx:isbn}
  %  {\printfield{isbn}}
  %  {}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{inproceedings}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/translator+others}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \usebibmacro{maintitle+booktitle(inproceedings)}%
  \midsentence
  \newunit\newblock
  \usebibmacro{event+venue+date}%
  \newunit\newblock
  \usebibmacro{byeditor+others}%
  \newunit\newblock
  \printfield{volumes}%
  \newunit\newblock
  \usebibmacro{series+number}%
  \newunit\newblock
  \printfield{note}%
  \newunit\newblock
  \printlist{organization}%
  \newunit\newblock
  \usebibmacro{volume+part}%
  \newunit
  \usebibmacro{publisher+location+date}%
  \newunit\newblock
  \usebibmacro{chapter+pages}%
  \newunit\newblock
  %\iftoggle{bbx:isbn}
   % {\printfield{isbn}}
  %  {}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{online}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author/editor+others/translator+others}%
  \setunit{\adddot\addspace}%
  \printtext[parens]{\usebibmacro{date}}%
  \setunit{\adddot\addspace}%
  \usebibmacro{title}%
  \setunit{\adddot\addspace}%
  \printlist{language}%
  \setunit{\adddot\addspace}%
  \usebibmacro{byauthor}%
  \setunit{\adddot\addspace}%
  \usebibmacro{byeditor+others}%
  \setunit{\adddot\addspace}%
  \printfield{version}%
  \setunit{\adddot\addspace}%
  \printfield{note}%
  \newunit\newblock
  \printlist{organization}%
  \setunit{\adddot\addspace}%
  \iftoggle{bbx:eprint}
    {\usebibmacro{eprint}}
    {}%
  \newunit\newblock
  \usebibmacro{url+urldate}%
  \setunit{\adddot\addspace}%
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{patent}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \printfield{type}%
  \setunit*{\addspace}%
  \printfield{number}%
  \newunit\newblock
  \printfield{note}%
  \newunit\newblock
  \usebibmacro{date}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

\DeclareBibliographyDriver{report}{%
  \usebibmacro{bibindex}%
  \usebibmacro{begentry}%
  \usebibmacro{author}%
  \setunit{\labelnamepunct}\newblock
  \usebibmacro{title}%
  \newunit
  \printlist{language}%
  \newunit\newblock
  \usebibmacro{byauthor}%
  \newunit\newblock
  \usebibmacro{institution+location}%
  \newunit\newblock
  \printfield{type}%
  \setunit*{\addspace}%
  \printfield{number}%
  \newunit\newblock
  \printfield{version}%
  \newunit\newblock
  \usebibmacro{date}%
  \newunit
  \printfield{note}%
  \newunit\newblock
  \usebibmacro{chapter+pages}%
  \newunit
  \printfield{pagetotal}%
  \newunit\newblock
 % \iftoggle{bbx:isbn}
  %  {\printfield{isrn}}
 %   {}%
  \newunit\newblock
  \usebibmacro{doi+eprint+url}%
  \newunit\newblock
  \usebibmacro{addendum+pubstate}%
  \setunit{\bibpagerefpunct}\newblock
  \usebibmacro{pageref}%
  \newunit\newblock
  \iftoggle{bbx:related}
    {\usebibmacro{related:init}%
     \usebibmacro{related}}
    {}%
  \usebibmacro{finentry}}

%%
%% Copyright (C) 2011-2013,2015-2018 by
%%   Joseph Wright <joseph.wright@morningstar2.co.uk>
%%
%% It may be distributed and/or modified under the conditions of
%% the LaTeX Project Public License (LPPL), either version 1.3c of
%% this license or (at your option) any later version.  The latest
%% version of this license is in the file:
%%
%%    http://www.latex-project.org/lppl.txt
%%
%% This work is "maintained" (as per LPPL maintenance status) by
%%   Joseph Wright.
%%
%% This work consists of the files biblatex-ieee.bib,
%%                                 biblatex-ieee.tex,
%%                                 ieee.bbx,
%%                                 ieee.cbx,
%%                                 ieee-alphabetic.bbx,
%%                                 ieee-alphabetic.cbx and
%%                                 magyar-ieee.lbx,
%%           and the derived files biblatex-ieee.pdf and
%%                                 biblatex-ieee-alphabetic.pdf.
%%
%%
%% End of file `ieee.bbx'.