Gecko [ 122.154.134.11 ]

Name	Size	Permission	Action
msc.sty	109.06 KB	-rw-r--r--

Code Editor : msc.sty

%% MSC Macro Package
%% file msc.sty
%% LaTeX macros to draw message sequence charts
%%
%%
%% Copyright 2002 V. Bos and S. Mauw
%
% This program may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.2
% of this license or (at your option) any later version.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.2 or later is part of all distributions of LaTeX 
% version 1999/12/01 or later.

% This program consists of the files 
%   msc.sty
%   manual.tex
%   manual.ps
%   refman.tex
%   refman.ps
%   biblio.bib
%   maintenance.tex
%   maintenance.ps
%   README
%   COPYRIGHT

% Address:
% Eindhoven University of Technology
% P.O. Box 513
% 5600 MB Eindhoven
% The Netherlands
% Email: sjouke@win.tue.nl, vbos@abo.fi
% Updates via: http://www.win.tue.nl/~sjouke/mscpackage.html
% and via CTAN directory: macros/latex/contrib/msc/
%
% RCS version: $Id: msc.sty,v 1.15 2004/03/15 11:58:33 vbos Exp $
%
\def\mscdate{2004/03/15}% update this whenever this file changes
\def\mscversion{1.14}%   update this whenever a new version is ready
\NeedsTeXFormat{LaTeX2e}% 
\ProvidesPackage{msc}[\mscdate, v\mscversion]
\typeout{msc version \mscversion. (\mscdate)}
\RequirePackage{color,pstricks,calc,ifthen}
%
% mscunit: the unit of msc lengths
\def\mscunit{cm}%
\def\setmscunit#1{\gdef\mscunit{#1}}
%
%
%
% msc lengths
% First the customizable lengths:

\newlength{\actionheight}% height of action symbols
\newlength{\actionwidth}% width of action symbol
\newlength{\bottomfootdist}% distance between bottom of foot symbol and frame
\newlength{\msccommentdist}% distance of comment to its instance
\newlength{\conditionheight}% height of condition symbols
\newlength{\conditionoverlap}% overlap of condition symbol
\newlength{\envinstdist}% distance between environments and nearest instance line
\newlength{\firstlevelheight}% height of level just below head symbols
\newlength{\hmscconditionheight}% height of hmsc condition symbol
\newlength{\hmscconditionwidth}% width of hmsc condition symbol
\newlength{\hmscconnectionradius}% radius of hmsc connection symbols
\newlength{\hmscreferenceheight}% height of hmsc reference symbol
\newlength{\hmscreferencewidth}% width of hmsc reference symbol
\newlength{\hmscstartsymbolwidth}% width of hmsc start symbol
\newlength{\inlineoverlap}% overlap of inline symbol
\newlength{\instbarwidth}% default width of vertical instance bars
\newlength{\instdist}% distance between (vertical) instance lines
\newlength{\instfootheight}% height of foot symbols
\newlength{\instheadheight}% height of head symbols
\newlength{\instwidth}%  width of header and foot symbols
\newlength{\labeldist}% distance between labels and message lines or head symbol boxes 
\newlength{\lastlevelheight}% height of level just above foot symbols
\newlength{\leftnamedist}% distance between left of frame and (top of) msc title 
\newlength{\levelheight}% height of a level
\newlength{\lostsymbolradius}% radius of the lost and found symbols
\newlength{\markdist}% distance between mark and its instance
\newlength{\measuredist}% user definable length for horizontal measure distance
\newlength{\measuresymbolwidth}% width of measure symbols
\newlength{\mscdocreferenceheight}% minimal height of mscdoc reference
\newlength{\mscdocreferencewidth}% minimal width of mscdoc reference
\newlength{\referenceoverlap}% overlap of reference symbol
\newlength{\regionbarwidth}% width of region bars
\newlength{\selfmesswidth}% length of horizontal arms of self messages
\newlength{\stopwidth}% width of the stop symbol
\newlength{\timerwidth}% width of the timer symbols
\newlength{\topheaddist}% distance between top of head symbols and frame
\newlength{\topnamedist}% distance between top of frame and (top of) msc title

%
% Now the internal lengths
\newlength{\tmp@X}
\newlength{\tmp@Y}
\newlength{\tmp@Xa}
\newlength{\tmp@Ya}
\newlength{\tmp@Xb}
\newlength{\tmp@Yb}
\newlength{\tmp@Xc}
\newlength{\tmp@Yc}
\newlength{\tmp@Xd}
\newlength{\tmp@Yd}
\newlength{\msc@currentheight}
\newlength{\msc@currentwidth}
\newlength{\msc@totalwidth}
\newlength{\msc@totalheight}
\newlength{\msc@commentdist}% distance of comment to its instance
%
%
\newcommand{\msc@incrcounter}[1]{\addtocounter{#1}{1}}%
%
% internal box
\newsavebox{\tmp@box}
%
% some internal offsets
\def\msc@leveloffset{0}% 
\def\mscscalefactor{1}%
\newcommand{\setmscscale}[1]{\def\mscscalefactor{#1}}%
%
% Command to change the footer color (legal values are black, gray,
% lightgray, and white)
\def\setfootcolor#1{\def\msc@footcolor{#1}}
%
% And some internal counters
\newcounter{mscinstcnt}
\newcounter{tmpcnt}
%
% \messlabelpos defines the position of message labels.
% The default value is "l" (left) other value(s) are "r" (right)
\def\timerpos{l}
%
% \msc@timerpos is the internal variant of \timerpos
% This internal variant is used by the actual  drawing commands for self messages
\def\msc@timerpos{l}
%
% \msc@settimerpos sets the internal \mes@timerpos
\def\msc@settimerpos#1{
  \ifthenelse{\not$\equal{#1}{l} \or \equal{#1}{r}$}{%
    \msc@unknowntimerposerr{#1}}{% else
    \def\msc@timerpos{#1}%
  }%
}
%
% \dummyinst{#1} (\dummyinst*{#1}) declares a dummy msc-instance and does not 
% draws its head symbol nor its instance axis until an instance create/start is 
% encountered. The starred version declares a fat instance.
% #1: nickname that can be used in \mess -like commands
% 
\def\dummyinst{\@ifstar{\msc@dummyinststar}{\msc@dummyinstnostar}}
\def\msc@dummyinstnostar#1{%
  \msc@makedummyinst{\the\instbarwidth}{#1}%
}
\def\msc@dummyinststar#1{% 
  \msc@makedummyinst{\the\instwidth}{#1}%
}
\def\msc@makedummyinst#1#2{%
  \@ifundefined{mscinst#2}{%
    \ifthenelse{\value{mscinstcnt}=2}{% Aha: this is the first msc instance, so, add the
      \addtolength{\msc@currentwidth}{\envinstdist}% left \envinstdist to \msc@currentwidth
    }{%not the first instance , so add the instdist to the \mec@currentwidth
      \addtolength{\msc@currentwidth}{\instdist}%
    }% and update x-pos of right environment
    \setlength{\tmp@X}{\msc@currentwidth+\envinstdist}%
    \msc@setinstxpos{envright}{\the\tmp@X}%
    % make an instance with empty inside name and empty above name:
    \msc@declinst{#2}{\relax}{\relax}{#1}%
    % make y-pos undefined, to make sure that no instance line will be drawn
    \msc@setinstypos{#2}{undefined}% --added sm
  }{% else: nickname #2 already defined!
    \msc@nicknamedefinederr{#2}%
  }%
}
%
% \declinst[*] declares a new msc-instance and draws its head symbol
% the starred versions makes a fat instance.
% #1: nickname that can be used in \mess
% #2: name of the instance (above instance head symbol)
% #3: name of the instance (inside instance head symbol)
%
%
\def\declinst{\@ifstar{\msc@declinststar}{\msc@declinstnostar}}
% 
% Some commands are defined as well (INSTNR is the arabic
% representation of the instance number):
%   \instabname#1: `above name' of instance with nickname #1 
%   \instinname#1: `inside name' of instance with nickname #1 
%   \instnicknameINSTNR: returns the nickname of instance INSTNR
%   \instxposINSTNR: returns the x-position of instance with nickname #1
%   \instyposINSTNR: returns the last y-position of instance with nickname #1
%   \instlinestyle#1: the line style (dashed or solid) of instance with nickname #1
\def\msc@declinstnostar#1#2#3{% user command to declare instances
  \msc@dummyinstnostar{#1}%
  %\inststart{#1}{#2}{#3}%
  % define above name and inside name
  \expandafter\def\csname instabname#1\endcsname{#2}% `above name'
  \expandafter\def\csname instinname#1\endcsname{#3}% `inside name'
  % draw the instance header symbol
  \msc@drawinstanceheadsymbol{#1}{\the\topheaddist}%
  % redefine the instance's y position
  \setlength{\tmp@Y}{\topheaddist+\instheadheight}%
  \msc@setinstypos{#1}{\the\tmp@Y}%
}
%
\def\msc@declinststar#1#2#3{% user command to declare instances
  \msc@dummyinststar{#1}%
  % define above name and inside name
  \expandafter\def\csname instabname#1\endcsname{#2}% `above name'
  \expandafter\def\csname instinname#1\endcsname{#3}% `inside name'
  % draw the instance header symbol
  \msc@drawinstanceheadsymbol{#1}{\the\topheaddist}%
  % redefine the instance's y position
  \setlength{\tmp@Y}{\topheaddist+\instheadheight}%
  \msc@setinstypos{#1}{\the\tmp@Y}%
}
%
% \msc@declinst: internal command to declare instances.
% Some commands are defined as well (INSTNR is the arabic
% representation of the instance number):
%   \instabnameINSTNR: returns the instance above name of #1
%   \instnicknameINSTNR: returns the nickname of instance #1
%   \instxposINSTNR: returns the x-position of instance with nickname #1
%   \instyposINSTNR: returns the last y-position of instance with nickname #1
%   \instlinestyle#1: the line style (dashed or solid) of instance with nickname #1
%   \instregionstyle#1: the region style (normal, coregion, suspension, or activation)
\def\msc@declinst#1#2#3#4{% internal command to declare instances
  \@ifundefined{mscinst#1}{%
    \@namedef{mscinst#1}{\relax}%  
    \expandafter\def\csname instabname#1\endcsname{#2}% `above name'
    \expandafter\def\csname instinname#1\endcsname{#3}% `inside name'
    \expandafter\def\csname instbarwidth#1\endcsname{#4}% width of the vertical instance bar
    % the x position of an instance, \instxpos#1, is stored as a string, not as
    % a TeX-length, since that would use up too much of TeX limited number of
    % length-registers.
    % However, this means we first have to calculate the x-pos, and then
    % assign the string representation of the result to \instxpos#1:
    \setlength{\tmp@X}{\msc@currentwidth}%
    \expandafter\edef\csname instxpos#1\endcsname{\the\tmp@X}%
    \ifthenelse{\lengthtest{\instbarwidth < #4}}%
      {%
       \expandafter\def\csname instisfat#1\endcsname{true}%
       \setlength{\tmp@Xa}{#4}%
       \addtolength{\tmp@X}{-.5\tmp@Xa}%
       \expandafter\edef\csname instlxpos#1\endcsname{\the\tmp@X}%
       \addtolength{\tmp@X}{\tmp@Xa}%
       \expandafter\edef\csname instrxpos#1\endcsname{\the\tmp@X}%
      }%
      {%
       \expandafter\def\csname instisfat#1\endcsname{false}%
       \expandafter\edef\csname instlxpos#1\endcsname{\the\tmp@X}%
       \expandafter\edef\csname instrxpos#1\endcsname{\the\tmp@X}%
      }%
    \expandafter\def\csname instnickname\arabic{mscinstcnt}\endcsname{#1}%
    \setlength{\tmp@Y}{\msc@currentheight}%
    \expandafter\edef\csname instypos#1\endcsname{\the\tmp@Y}%
    \expandafter\def\csname instlinestyle#1\endcsname{solid}%
    \expandafter\def\csname instfootcolor#1\endcsname{\msc@footcolor}%
    \expandafter\def\csname instregionstyle#1\endcsname{normal}%
    \msc@incrcounter{mscinstcnt}%    
  }{% else, #1 already defined
    \msc@nicknamedefinederr{#1}%
  }%
}
%
% \msc@instnickname gets the nickname of msc instance with number #1
% (This macro is used in \msc@drawinstancelevels)
\def\msc@instnickname#1{%
  \csname instnickname\arabic{#1}\endcsname%
}
% \msc@instabname gets the above name of instance #1
\def\msc@instabname#1{%
  \csname instabname#1\endcsname%
}
% \msc@instinname gets the inside name of instance #1
\def\msc@instinname#1{%
  \csname instinname#1\endcsname%
}
%
% \msc@instxpos gets the x position (i.e., horizontal position) of the
% msc instance with nickname #1. 
\def\msc@instxpos#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\csname instxpos#1\endcsname}%
}
%
%
\def\msc@instlxpos#1{
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\csname instlxpos#1\endcsname}%
}
%
\def\msc@instrxpos#1{
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\csname instrxpos#1\endcsname}%
}
%
% \msc@setinstxpos sets the (l/r) x position of instance with nickname #1 to
% the string  #2
\def\msc@setinstxpos#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname instxpos#1\endcsname{#2}%
    \expandafter\edef\csname instlxpos#1\endcsname{#2}%
    \expandafter\edef\csname instrxpos#1\endcsname{#2}%
  }%
}
%
\def\msc@setinstlxpos#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname instlxpos#1\endcsname{#2}%
  }%
}
%
\def\msc@setinstrxpos#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname instrxpos#1\endcsname{#2}%
  }%
}
%
% \msc@instypos gets the last y position (i.e., vertical position) of the
% msc instance with nickname #1. 
\def\msc@instypos#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \csname instypos#1\endcsname}%
}
%
% \msc@setinstypos sets the last y position of instance with nickname #1 to
% the string #2
\def\msc@setinstypos#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname instypos#1\endcsname{#2}%
  }%
}
%
% Change \instlinestyle command of msc instance with nickname #1 into #2
% #2 should be one of: solid, dashed, or dotted
\def\msc@setinstlinestyle#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \ifthenelse{\not$\equal{#2}{solid} \or
                      \equal{#2}{dashed} \or
                      \equal{#2}{dotted}$}{% unknown linestyle
      \msc@unknownlinestyleerr{#2}}{%
      \expandafter\def\csname instlinestyle#1\endcsname{#2}%
    }%
  }%
}
%
% \msc@instlinestyle returns the linestyle of instance with nickname #1
\def\msc@instlinestyle#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \csname instlinestyle#1\endcsname}%
}
%
% Change the foot color for instance with nickname #1 into #2
\def\msc@setinstfootcolor#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\def\csname instfootcolor#1\endcsname{#2}%
  }%
}
%
% \msc@instfootcolor returns the color of the footer of instance with nicknam #1
\def\msc@instfootcolor#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \csname instfootcolor#1\endcsname}%
}
%
% Change \instregionstyle command of msc instance with nickname #1 into #2
% #2 should be one of: normal, coregion, suspension, or activation
\def\msc@setinstregionstyle#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \ifthenelse{\not$\equal{#2}{normal} \or
                      \equal{#2}{coregion} \or
                      \equal{#2}{suspension} \or
                      \equal{#2}{activation}$}
      {% unknown region style
       \msc@unknownregionstyleerr{#2}
      }{%
       \expandafter\def\csname instregionstyle#1\endcsname{#2}%
      }%
    \ifthenelse{\equal{#2}{suspension} \or \equal{#2}{activation}}
      {%
       \ifthenelse{\equal{\msc@instisfat{#1}}{true}}
         {\relax}
         {%
          \setlength{\tmp@X}{\msc@instxpos{#1}}%
          \setlength{\tmp@Xa}{\regionbarwidth}%
          \addtolength{\tmp@X}{-.5\tmp@Xa}%
          \msc@setinstlxpos{#1}{\the\tmp@X}%
          \addtolength{\tmp@X}{\tmp@Xa}%
          \msc@setinstrxpos{#1}{\the\tmp@X}%
         }
      }{% new region style is normal or coregion
       \ifthenelse{\equal{\msc@instisfat{#1}}{true}}%
         {\relax}%
         {\msc@setinstbarwidth{#1}{\instbarwidth}%
          \msc@setinstlxpos{#1}{\msc@instxpos{#1}}%
          \msc@setinstrxpos{#1}{\msc@instxpos{#1}}%
         }%
     }%
  }%
}
%
% \msc@instregionstyle returns the region style of instance with nickname #1
\def\msc@instregionstyle#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \csname instregionstyle#1\endcsname}%
}
%
% \msc@instbarwidth returns the width of the bar of instance with nickname #1
\def\msc@instbarwidth#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \csname instbarwidth#1\endcsname}%
}
%
% \msc@setinstbarwidth sets the width of the bar  of instance with nickname #1
% to the string #2
\def\msc@setinstbarwidth#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname instbarwidth#1\endcsname{#2}%
    \ifthenelse{\lengthtest{\instbarwidth < #2}}%
      {\expandafter\def\csname instisfat#1\endcsname{true}}%
      {\expandafter\def\csname instisfat#1\endcsname{false}}%
  }%
}
%
%\msc@isfateinst returns one of the strings `true' of `false', indicating if 
% the instance with nickname #1 is a fat instance.
\def\msc@instisfat#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \csname instisfat#1\endcsname}%
}
%
%
% \changeinstbarwidth changes the instance width of instance with nickname #1 to
% the length #2
\def\changeinstbarwidth#1#2{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}%
  {% else, #1 is defined
    \msc@drawinstanceline{#1}%
    \setlength{\tmp@X}{\msc@instxpos{#1}}%
    \setlength{\tmp@Y}{\msc@currentheight}%
    \msc@setinstypos{#1}{\the\tmp@Y}%
    \setlength{\tmp@Xb}{#2}%
    \ifthenelse{\lengthtest{\tmp@Xb > \instbarwidth}}%
      {%
       \setlength{\tmp@Xb}{0.5\tmp@Xb}%
       \addtolength{\tmp@Xb}{\tmp@X}}%
      {%
       \setlength{\tmp@Xb}{\tmp@X}}%
    \ifthenelse{\equal{true}{\msc@instisfat{#1}}}
      {%
       \setlength{\tmp@Xa}{\msc@instbarwidth{#1}}%
       \setlength{\tmp@Xa}{0.5\tmp@Xa}%
       \addtolength{\tmp@Xa}{\tmp@X}%
      }{%
       \setlength{\tmp@Xa}{\tmp@X}%
      }%
    \psline(\tmp@Xa,-\tmp@Y)(\tmp@Xb,-\tmp@Y)%
    \setlength{\tmp@Xb}{#2}%
    \ifthenelse{\lengthtest{\tmp@Xb > \instbarwidth}}%
      {%
       \setlength{\tmp@Xb}{-0.5\tmp@Xb}%
       \addtolength{\tmp@Xb}{\tmp@X}}%
      {%
       \setlength{\tmp@Xb}{\tmp@X}}%
    \ifthenelse{\equal{true}{\msc@instisfat{#1}}}
      {%
       \setlength{\tmp@Xa}{\msc@instbarwidth{#1}}%
       \setlength{\tmp@Xa}{-0.5\tmp@Xa}%
       \addtolength{\tmp@Xa}{\tmp@X}%
      }{%
       \setlength{\tmp@Xa}{\tmp@X}%
      }%
    \psline(\tmp@Xa,-\tmp@Y)(\tmp@Xb,-\tmp@Y)%
    \msc@setinstbarwidth{#1}{#2}%
  }%
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DUMMY INSTANCES (start and stop)
%
% Start a dummy inst
%
% \inststart{#1}{#2}{#3}
% #1: nickname of stared instance
% #2: name of the instance (above instance head symbol)
% #3: name of the instance (inside instance head symbol)
%
\def\inststart#1#2#3{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    % set the above and inside names
    \expandafter\def\csname instabname#1\endcsname{#2}% `above name'
    \expandafter\def\csname instinname#1\endcsname{#3}% `inside name'
    % draw the instance header symbol
    \msc@drawinstanceheadsymbol{#1}{\the\msc@currentheight}%
    % redefine the instance's y position
    \setlength{\tmp@Y}{\msc@currentheight+\instheadheight}%
    \msc@setinstypos{#1}{\the\tmp@Y}%
  }
}
%
% \inststop{#1}
% #1: nick name of instance
% 
% Draws the footer of #1 at current level. 
\def\inststop#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \addtolength{\msc@currentheight}{\lastlevelheight}
    \msc@drawinstanceline{#1}%
    \setlength{\tmp@Y}{\msc@currentheight}%
    \msc@drawinstancefootsymbol{#1}{\the\tmp@Y}%
    \addtolength{\msc@currentheight}{-\lastlevelheight}
    \msc@setinstypos{#1}{undefined}
  }
}
%
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%5
%
% CREATE
%
% \create creates a new msc-instance and draws its head symbol
% #1: text above creation message
% #2: nickname of creating instance
% #3: nickname of created instance
% #4: name of the instance (above instance head symbol)
% #5: name of the instance (inside instance head symbol)
% 
% Some commands are defined as well (INSTNR is the arabic
% representation of the instance number):
%   \instabname#3: `above name' of instance with nickname #3 
%   \instinname#3: `inside name' of instance with nickname #3 
%   \instlinestyle#3: the line style (dashed or solid) of instance with nickname #3
\newcommand{\create}{%
  \@ifstar%
  {\def\mess@style{mess}\def\mess@linsestyle{dashed}\create@A}{\def\mess@style{mess}\def\mess@linestyle{solid}\create@A}%
}%
\newcommand{\create@A}[1]{%
  \def\mess@labeltext{#1}%
  \create@B%
}
\newcommand{\create@B}[2][t]{%
  \def\mess@labelposition{#1}%
  \def\mess@sender{#2}%  
  \create@C%
}
\newcommand{\create@C}[4][0.5]{%
  \def\mess@labelplacement{#1}%
  \def\mess@receiver{#2}%
  \def\mess@leveloffset{0}%
  \def\mess@instanceoffset{0.5\instwidth}%
%
  \expandafter\@ifundefined{mscinst\mess@sender}{%
    \msc@instundefinederr{\mess@sender}}{% else, \mess@sender is defined
  \expandafter\@ifundefined{mscinst\mess@receiver}{%
    \msc@instundefinederr{\mess@receiver}}{% else, \mess@receiver is defined
    \expandafter\def\csname instabname\mess@receiver\endcsname{#3}% `above name'
    \expandafter\def\csname instinname\mess@receiver\endcsname{#4}% `inside name'
    % draw the instance header symbol
    \setlength{\tmp@X}{\msc@instxpos{\mess@receiver}}% x-center head box
    \setlength{\tmp@Y}{\msc@currentheight}% y-center head box
    \setlength{\tmp@Xa}{-0.5\instwidth+\tmp@X}% x-upperleft head box
    \setlength{\tmp@Ya}{\msc@currentheight-0.5\instheadheight}%
    \setlength{\tmp@Xb}{\tmp@Xa+\instwidth}% x-lowerright head box
    \setlength{\tmp@Yb}{\tmp@Ya+\instheadheight}% y-lowerright head box
    \psframe[dimen=middle](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
    \rput[B](\tmp@X,-\tmp@Ya){\raisebox{\labeldist}{\makebox[0pt][c]{#3}}}%
    \rput[B](\tmp@X,-\tmp@Y){\raisebox{-.5ex}{\makebox[0pt][c]{#4}}}%
    % redefine the instance's y position
    \setlength{\tmp@Y}{\msc@currentheight+0.5\instheadheight}%
    \msc@setinstypos{\mess@receiver}{\the\tmp@Y}%
    % draw creation arrow
    \msc@drawarrow%
  }%
  }%
}
%
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% INLINE EXPRESSIONS (inlines)
%
%
% \inlineestart creates an inline expression at the current level
% [#1]: left overlap
% [#2]: right overlap
% #3: nickname of the inline
% #4: text of the inline
% #5: first instance of the inline
% #6: final instance of the inline
\newcommand{\inlinestart}[1][\inlineoverlap]{%
  \def\msc@leftoverlap{#1}\msc@inlinecont%
}
\newcommand{\msc@inlinecont}[5][\msc@leftoverlap]{\msc@declinline{\msc@leftoverlap}{#1}{#2}{#3}{#4}{#5}}%
%
% \inlineend draws and ends the inline expression with nickname #1
% 
\newcommand{\inlineend}{%
  \@ifstar{\msc@inlineends}{\msc@inlineend}}
%
% \inlineseparator draws a ``separator'' (horizontal dashed line) through 
% inline expression with nickname #1
\newcommand{\inlineseparator}[1]{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \setlength{\tmp@Y}{\msc@currentheight}%
    \psline[linestyle=dashed](\msc@inlulx{#1},-\tmp@Y)(\msc@inllrx{#1},-\tmp@Y)%
  }%
}
%
% internal commands to implement the inline expressions:
% #1: left overlap
% #2: right overlap
% #3: nickname of the inline
% #4: text of the inline
% #5: first instance of the inline
% #6: final instance of the inline
%
\def\msc@declinline#1#2#3#4#5#6{%
  \@ifundefined{mscinl#3}{%
    \@ifundefined{mscinst#5}{% #5 is not an instance nickname
      \msc@instundefinederr{#5}}{%
      \@ifundefined{mscinst#6}{% #6 is not an instance nickname
        \msc@instundefinederr{#6}}{%
        \ifthenelse{\lengthtest{\msc@instxpos{#5}>\msc@instxpos{#6}}}{%
          \msc@inlfirstlasterror{#3}{#5}{#6}}{%
          \@namedef{mscinl#3}{\relax}%
          \expandafter\def\csname inltext#3\endcsname{\raisebox{\depth}[\totalheight][0pt]{#4}}%
          \ifthenelse{\equal{true}{\msc@instisfat{#5}}}%
          {%
            \setlength{\tmp@X}{\msc@instlxpos{#5}-#1}%
          }%
          {%
            \setlength{\tmp@X}{\msc@instxpos{#5}-#1}%
          }%
          \expandafter\edef\csname inlulx#3\endcsname{\the\tmp@X}%
          \expandafter\edef\csname inluly#3\endcsname{\the\msc@currentheight}%
          \ifthenelse{\equal{true}{\msc@instisfat{#6}}}%
          {%
            \setlength{\tmp@X}{\msc@instrxpos{#6}+#2}%
          }%
          {%
            \setlength{\tmp@X}{\msc@instxpos{#6}+#2}%
          }%
          \expandafter\edef\csname inllrx#3\endcsname{\the\tmp@X}%
          \expandafter\edef\csname inllry#3\endcsname{undefined}%
          % two additional instances are defined
          \msc@declinst{#3left}{\relax}{\relax}{\the\instbarwidth}% left of inline
          \msc@setinstxpos{#3left}{\msc@inlulx{#3}}%
          \msc@setinstlxpos{#3left}{\msc@inlulx{#3}}%
          \msc@setinstrxpos{#3left}{\msc@inlulx{#3}}%
          \msc@setinstypos{#3left}{undefined}% no instance line drawing
          \msc@declinst{#3right}{\relax}{\relax}{\the\instbarwidth}% left of inline
          \msc@setinstxpos{#3right}{\msc@inllrx{#3}}%
          \msc@setinstlxpos{#3right}{\msc@inllrx{#3}}%
          \msc@setinstrxpos{#3right}{\msc@inllrx{#3}}%
          \msc@setinstypos{#3right}{undefined}% no instance line drawing
        }%
      }%
    }%
  }{% nickname #3 already defined
    \msc@nicknamedefinederr{#3}%
  }%
}
%
% \msc@inlulx gets the upper-left x-position of inline with nickname #1.
\def\msc@inlulx#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \csname inlulx#1\endcsname%
  }%
}
%
% \msc@inluly gets the upper-left y-position of inline with nickname #1.
\def\msc@inluly#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \csname inluly#1\endcsname%
  }%
}
%
% \msc@inllrx gets the lower-right x-position of inline with nickname #1.
\def\msc@inllrx#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \csname inllrx#1\endcsname%
  }%
}
%
% \msc@inllry gets the lower-right y-position of inline with nickname #1.
\def\msc@inllry#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \csname inllry#1\endcsname%
  }%
}
%
% \msc@inltext gets the text of inline with nickname #1
\def\msc@inltext#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \csname inltext#1\endcsname%
  }%
}
%
% \msc@inlineend completes the inline with nickname #1
% (the bottom line is solid)
\def\msc@inlineend#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname inllry#1\endcsname{\the\msc@currentheight}%
    \setlength{\tmp@Xa}{\msc@inlulx{#1}}%
    \setlength{\tmp@Ya}{\msc@inluly{#1}}%
    \setlength{\tmp@Xb}{\msc@inllrx{#1}}%
    \setlength{\tmp@Yb}{\msc@inllry{#1}}%
%% Debug info:
%    \typeout{(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)}%
    \psframe[dimen=middle](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
    \settowidth{\tmp@X}{\msc@inltext{#1}}%
    \setlength{\tmp@X}{1.1\tmp@X+\labeldist}%
    \settoheight{\tmp@Y}{\msc@inltext{#1}}%
    \setlength{\tmp@Y}{1.1\tmp@Y+\labeldist}%
    \setlength{\tmp@Xb}{\tmp@X+\labeldist}%
    \setlength{\tmp@Yb}{\tmp@Y+\labeldist}%
    \rput(\tmp@Xa,-\tmp@Ya){%
      \rput[tl](\labeldist,-\labeldist){\msc@inltext{#1}}%
      \psline(0,-\tmp@Yb)(\tmp@X,-\tmp@Yb)(\tmp@Xb,-\tmp@Y)(\tmp@Xb,0)%
    }%
  }%
}
%
% \msc@inlineends completes the inline with nickname #1
% (the bottom line is dashed)
\def\msc@inlineends#1{%
  \expandafter\@ifundefined{mscinl#1}{%
    \msc@inlundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname inllry#1\endcsname{\the\msc@currentheight}%
    \setlength{\tmp@Xa}{\msc@inlulx{#1}}%
    \setlength{\tmp@Ya}{\msc@inluly{#1}}%
    \setlength{\tmp@Xb}{\msc@inllrx{#1}}%
    \setlength{\tmp@Yb}{\msc@inllry{#1}}%
%% Debug info:
%    \typeout{(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)}%
    % first the solid part of the inline expression:
    \psline(\tmp@Xa,-\tmp@Yb)(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
    % then the dashed bottom line:
    \psline[linestyle=dashed](\tmp@Xa,-\tmp@Yb)(\tmp@Xb,-\tmp@Yb)
    \settowidth{\tmp@X}{\msc@inltext{#1}}%
    \setlength{\tmp@X}{1.1\tmp@X+\labeldist}%
    \settoheight{\tmp@Y}{\msc@inltext{#1}}%
    \setlength{\tmp@Y}{1.1\tmp@Y+\labeldist}%
    \setlength{\tmp@Xb}{\tmp@X+\labeldist}%
    \setlength{\tmp@Yb}{\tmp@Y+\labeldist}%
    \rput(\tmp@Xa,-\tmp@Ya){%
      \rput[tl](\labeldist,-\labeldist){\msc@inltext{#1}}%
      \psline(0,-\tmp@Yb)(\tmp@X,-\tmp@Yb)(\tmp@Xb,-\tmp@Y)(\tmp@Xb,0)%
    }%
  }%
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% REFERENCES
%
%
% \referencestart creates an msc reference at the current level
% [#1] : left overlap
% [#2] : right overlap
% #3: nickname of the reference
% #4: text of the reference
% #5: first instance of the reference
% #6: final instance of the reference
\newcommand{\referencestart}[1][\referenceoverlap]{%
  \def\msc@leftoverlap{#1}\msc@referencecont%
}
\newcommand{\msc@referencecont}[5][\referenceoverlap]{%
  \msc@declreference{\msc@leftoverlap}{#1}{#2}{#3}{#4}{#5}%
  \setcounter{tmpcnt}{0}%
  \msc@reffindfirst{#2}{\msc@drawtorefaux}%
}
%
% \referenceend draws and ends the reference with nickname #1 
\newcommand{\referenceend}[1]{%
  \msc@drawreference{#1}%
  \setcounter{tmpcnt}{0}%
  \setlength{\tmp@Y}{\msc@currentheight}%
  \msc@reffindfirst{#1}{\msc@refresetypos{\the\tmp@Y}}%
}
%
% internal commands to implement references:
% #1: left overlap
% #2: right overlap
% #3: nickname of the reference
% #4: text of the reference
% #5: first instance of the reference
% #6: final instance of the reference
%
\def\msc@declreference#1#2#3#4#5#6{%
  \@ifundefined{mscref#3}{%
    \@ifundefined{mscinst#5}{% #5 is not an instance nickname
      \msc@instundefinederr{#5}}{%
      \@ifundefined{mscinst#6}{% #6 is not an instance nickname
        \msc@instundefinederr{#6}}{%
        \ifthenelse{\lengthtest{\msc@instxpos{#5}>\msc@instxpos{#6}}}{%
          \msc@reffirstlasterror{#3}{#5}{#6}}{%
          \@namedef{mscref#3}{\relax}%
          \expandafter\def\csname reftext#3\endcsname{#4}%
          \ifthenelse{\equal{true}{\msc@instisfat{#5}}}%
          {%
            \setlength{\tmp@X}{\msc@instlxpos{#5}-#1}%
          }%
          {%
            \setlength{\tmp@X}{\msc@instxpos{#5}-#1}%
          }%
          \expandafter\edef\csname refulx#3\endcsname{\the\tmp@X}%
          \expandafter\edef\csname refuly#3\endcsname{\the\msc@currentheight}%
          \ifthenelse{\equal{true}{\msc@instisfat{#6}}}%
          {%
            \setlength{\tmp@X}{\msc@instrxpos{#6}+#2}%
          }%
          {%
            \setlength{\tmp@X}{\msc@instxpos{#6}+#2}%
          }%
          \expandafter\edef\csname reflrx#3\endcsname{\the\tmp@X}%
          \expandafter\edef\csname reflry#3\endcsname{undefined}%
          \expandafter\def\csname reffirst#3\endcsname{#5}%
          \expandafter\def\csname reffinal#3\endcsname{#6}%
          % two additional instances are defined
          \msc@declinst{#3left}{\relax}{\relax}{\the\instbarwidth}% left of reference
          \msc@setinstxpos{#3left}{\msc@refulx{#3}}%
          \msc@setinstlxpos{#3left}{\msc@refulx{#3}}%
          \msc@setinstrxpos{#3left}{\msc@refulx{#3}}%
          \msc@setinstypos{#3left}{undefined}% no instance line drawing
          \msc@declinst{#3right}{\relax}{\relax}{\the\instbarwidth}% left of reference
          \msc@setinstxpos{#3right}{\msc@reflrx{#3}}%
          \msc@setinstlxpos{#3right}{\msc@reflrx{#3}}%
          \msc@setinstrxpos{#3right}{\msc@reflrx{#3}}%
          \msc@setinstypos{#3right}{undefined}% no instance line drawing
        }%
      }%
    }%
  }{% nickname #3 already defined
    \msc@nicknamedefinederr{#3}%
  }%
}
%
% \msc@refulx gets the upper-left x-position of reference with nickname #1.
\def\msc@refulx#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname refulx#1\endcsname%
  }%
}
%
% \msc@refuly gets the upper-left y-position of reference with nickname #1.
\def\msc@refuly#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname refuly#1\endcsname%
  }%
}
%
% \msc@reflrx gets the lower-right x-position of reference with nickname #1.
\def\msc@reflrx#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname reflrx#1\endcsname%
  }%
}
%
% \msc@reflry gets the lower-right y-position of reference with nickname #1.
\def\msc@reflry#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname reflry#1\endcsname%
  }%
}
%
% \msc@reftext gets the text of reference with nickname #1
\def\msc@reftext#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname reftext#1\endcsname%
  }%
}
%
% \msc@reftext gets the nickname of the first instance of the reference with nickname #1
\def\msc@reffirst#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname reffirst#1\endcsname%
  }%
}
%
% \msc@reftext gets the nickname of the final instance of the reference with nickname #1
\def\msc@reffinal#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \csname reffinal#1\endcsname%
  }%
}
%
% \msc@drawreference completes the reference with nickname #1
\def\msc@drawreference#1{%
  \expandafter\@ifundefined{mscref#1}{%
    \msc@refundefinederr{#1}}{% else, #1 is defined
    \expandafter\edef\csname reflry#1\endcsname{\the\msc@currentheight}%
    \setlength{\tmp@Xa}{\msc@refulx{#1}}%
    \setlength{\tmp@Ya}{\msc@refuly{#1}}%
    \setlength{\tmp@Xb}{\msc@reflrx{#1}}%
    \setlength{\tmp@Yb}{\msc@reflry{#1}}%
%% Debug info:
%    \typeout{(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)}%
    \psframe[dimen=middle,framearc=0.25](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)% note: rounded corners
    \setlength{\tmp@X}{\tmp@Xb-\tmp@Xa}%
    \setlength{\tmp@Y}{\tmp@Yb-\tmp@Ya}%
    \rput(\tmp@Xa,-\tmp@Ya){%
      \rput[B](.5\tmp@X,-.5\tmp@Y){\raisebox{-.5ex}{\makebox[0pt][c]{\msc@reftext{#1}}}}%
    }%
  }%
}
%
\def\msc@reffindfirst#1#2{%
  \ifthenelse{\value{tmpcnt} < \value{mscinstcnt}}{%
% Debug info:
%    \typeout{(drawtoref) checking \msc@instnickname{tmpcnt}}%
    \ifthenelse{\equal{\msc@instnickname{tmpcnt}}{\msc@reffirst{#1}}}{% first instance found
% Debug info:
%      \typeout{first found: \msc@instnickname{tmpcnt}}%
      #2{#1}}{% else, keep on looking
      \msc@incrcounter{tmpcnt}%
      \msc@reffindfirst{#1}{#2}}}{% done ! all instances checked
  }%
}
%
\def\msc@drawtorefaux#1{%
  \ifthenelse{\value{tmpcnt} < \value{mscinstcnt}}{%
% Debug info:
%    \typeout{(drawtorefaux) checking \msc@instnickname{tmpcnt}}%
   \msc@drawinstanceline{\msc@instnickname{tmpcnt}}%
   \msc@setinstypos{\msc@instnickname{tmpcnt}}{undefined}%
   \ifthenelse{\equal{\msc@instnickname{tmpcnt}}{\msc@reffinal{#1}}}{% final instance found
% Debug info:
%      \typeout{final found: \msc@instnickname{tmpcnt}}%
     }{% else, non-final
      \msc@incrcounter{tmpcnt}%
      \msc@drawtorefaux{#1}}%
  }{% done ! all instances checked
  }%
}
%
\def\msc@refresetypos#1#2{%
  \ifthenelse{\value{tmpcnt} < \value{mscinstcnt}}{%
% Debug info:
%    \typeout{(drawtorefaux) checking \msc@instnickname{tmpcnt}}
   \msc@setinstypos{\msc@instnickname{tmpcnt}}{#1}%
   \ifthenelse{\equal{\msc@instnickname{tmpcnt}}{\msc@reffinal{#2}}}{% final instance found
% Debug info:
%      \typeout{final found: \msc@instnickname{tmpcnt}}%
     }{% else, non-final
      \msc@incrcounter{tmpcnt}%
      \msc@refresetypos{#1}{#2}}%
  }{% done ! all instances checked
  }%
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  CO-REGIONS
%
% \coregionstart starts a coregion on instance #1 (nickname) in the current level.
\def\coregionstart#1{\regionstart{coregion}{#1}}
% \coregionend ends a coregion on instance #1 (nickname) in the current level.
\def\coregionend#1{\regionend{#1}}%
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% REGIONS (normal, coregion, suspension, and activation)
%
%
% \regionstart{#1}{#2}
% starts a region
% #1: region style: normal, coregion, suspension, or activation
% #2: nickname: nick name of the instance
\def\regionstart#1#2{%
  \expandafter\@ifundefined{mscinst#2}{%
    \msc@instundefinederr{#2}}{% else, #2 is defined
    \msc@drawinstanceline{#2}%
    \msc@setinstregionstyle{#2}{#1}%
    \msc@drawregionstart{#2}%
  }%
}
%
% \regionend{#1}
% ends the region of instance with nickname #1
\def\regionend#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    \msc@drawinstanceline{#1}%
    \msc@drawregionend{#1}%
    \msc@setinstregionstyle{#1}{normal}%    
  }%
}
%
%
\def\msc@drawregionstart#1{%
  \setlength{\tmp@Y}{\msc@currentheight}%
  \ifthenelse{\equal{\msc@instisfat{#1}}{true}}
    {%
     \setlength{\tmp@Xa}{\msc@instlxpos{#1}}%
     \setlength{\tmp@Xb}{\msc@instrxpos{#1}}%
     \psline(\tmp@Xa,-\tmp@Y)(\tmp@Xb,-\tmp@Y)%
    }
    {%
     \setlength{\tmp@Xa}{-.5\regionbarwidth+\msc@instxpos{#1}}%
     \setlength{\tmp@Xb}{.5\regionbarwidth+\msc@instxpos{#1}}%
     \psline(\tmp@Xa,-\tmp@Y)(\tmp@Xb,-\tmp@Y)%
    }
  \msc@setinstypos{#1}{\the\tmp@Y}%
}
%
%
\def\msc@drawregionend#1{%
  \setlength{\tmp@Y}{\msc@currentheight}%
  \ifthenelse{\equal{\msc@instisfat{#1}}{true}}
    {%
     \setlength{\tmp@Xa}{\msc@instlxpos{#1}}%
     \setlength{\tmp@Xb}{\msc@instrxpos{#1}}%
     \psline(\tmp@Xa,-\tmp@Y)(\tmp@Xb,-\tmp@Y)%
    }
    {\setlength{\tmp@Xa}{-.5\regionbarwidth+\msc@instxpos{#1}}%
     \setlength{\tmp@Xb}{.5\regionbarwidth+\msc@instxpos{#1}}%
     \psline(\tmp@Xa,-\tmp@Y)(\tmp@Xb,-\tmp@Y)%
    }
  \msc@setinstypos{#1}{\the\tmp@Y}%
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% MESSAGE ARROWS
%
% \messarrowscale sets the arrow scale
\def\messarrowscale#1{\psset{arrowscale=#1}}
%
% \msc@setleveloffset sets the internal level offset
\def\msc@setleveloffset#1{%
  \def\msc@leveloffset{#1}%
}

% \mess has one optional argument to define the position of
% the label of a self message.
\newcommand{\mess}{%
  \@ifstar%
  {\def\mess@style{mess}\def\mess@linestyle{dashed}\mess@A}{\def\mess@style{mess}\def\mess@linestyle{solid}\mess@A}%
}%
%
\newcommand{\mess@A}[2][l]{%
 \def\selfmess@position{#1}%
 \def\mess@labeltext{#2}%
 \mess@B%
}%
\newcommand{\mess@B}[2][\ifx\mess@sender\mess@receiver \selfmess@position\else t\fi]{%
  \def\mess@labelposition{#1}%
  \def\mess@sender{#2}%
  \mess@C%
}
\newcommand{\mess@C}[2][0.5]{%
  \def\mess@labelplacement{#1}%
  \def\mess@receiver{#2}%
  \mess@D%
}
\newcommand{\mess@D}[1][\ifx\mess@sender\mess@receiver 1\else 0\fi]{%
  \edef\mess@leveloffset{#1}%
  \mess@E%
}
\newcommand{\mess@E}[1][0\mscunit]{%
  \edef\mess@instanceoffset{#1}%
  \msc@drawarrow%
}
\newcommand{\msc@drawarrow}{%
  \expandafter\@ifundefined{mscinst\mess@sender}{%
    \msc@instundefinederr{\mess@sender}}{% else, sender is defined
    \expandafter\@ifundefined{mscinst\mess@receiver}{%
      \msc@instundefinederr{\mess@receiver}}{% else, receiver is defined
      \ifx\mess@sender\mess@receiver\msc@drawselfarrow\else\msc@drawnonselfarrow\fi%
    }%
  }%
}
\newcommand{\msc@drawselfarrow}{%
  \ifthenelse{\equal{\selfmess@position}{l} \or%
              \equal{\selfmess@position}{r}%
  }{%
    \ifthenelse{\equal{\selfmess@position}{l}}%
    {%
      \setlength{\tmp@Xa}{\msc@instlxpos{\mess@sender} - \selfmesswidth}%
      \setlength{\tmp@Xb}{\tmp@Xa}%
    }{% ELSE
      \setlength{\tmp@Xa}{\msc@instrxpos{\mess@sender} + \selfmesswidth}%
      \setlength{\tmp@Xb}{\tmp@Xa}%
    }%
    \setlength{\tmp@Ya}{\msc@currentheight}%
    \setlength{\tmp@Yb}{\msc@currentheight + (\levelheight * \mess@leveloffset)}%
    \msc@computelabelcoords%
    \msc@computelabelspec%
    \rput[\msc@labelrefpoint](\tmp@X,-\tmp@Y){\msc@labelbox{\mess@labeltext}}%
    \ifthenelse{\equal{\selfmess@position}{l}}%
    {%
      \setlength{\tmp@Xa}{\msc@instlxpos{\mess@sender}}%
      \setlength{\tmp@Xc}{\msc@instlxpos{\mess@sender} - \mess@instanceoffset}%
    }{% ELSE
      \setlength{\tmp@Xa}{\msc@instrxpos{\mess@sender}}%
      \setlength{\tmp@Xc}{\msc@instrxpos{\mess@sender} + \mess@instanceoffset}%
    }%
    \ifthenelse{\equal{\mess@style}{mess}}%
    {% THEN message arrow
      \psline[linestyle=\mess@linestyle]{->}%
             (\tmp@Xa,-\tmp@Ya)%
             (\tmp@Xb,-\tmp@Ya)%
             (\tmp@Xb,-\tmp@Yb)%
             (\tmp@Xc,-\tmp@Yb)%
    }{% ELSE order arrow
      \setlength{\tmp@Yd}{.5\tmp@Yb + .5\tmp@Ya}%
      \psline[linestyle=\mess@linestyle]{->}%
             (\tmp@Xa,-\tmp@Ya)%
             (\tmp@Xb,-\tmp@Ya)%
             (\tmp@Xb,-\tmp@Yd)%
      \psline[linestyle=\mess@linestyle]%
             (\tmp@Xb,-\tmp@Yd)%
             (\tmp@Xb,-\tmp@Yb)%
             (\tmp@Xc,-\tmp@Yb)%
    }%
  }{% ELSE
    \msc@illegalselfmesspositionerr{\selfmess@position}%
  }%
}
\newcommand{\msc@drawnonselfarrow}{%
    \ifthenelse{\lengthtest{\msc@instxpos{\mess@sender} < \msc@instxpos{\mess@receiver}}}%
               {\setlength{\tmp@Xa}{\msc@instrxpos{\mess@sender}}%
                 \setlength{\tmp@Xb}{\msc@instlxpos{\mess@receiver}}%
                 \addtolength{\tmp@Xb}{-\mess@instanceoffset}}%
               {\setlength{\tmp@Xa}{\msc@instlxpos{\mess@sender}}%
                 \setlength{\tmp@Xb}{\msc@instrxpos{\mess@receiver}}%
                 \addtolength{\tmp@Xb}{\mess@instanceoffset}}%
    \setlength{\tmp@Ya}{\msc@currentheight}%
    \setlength{\tmp@Yb}{\msc@currentheight + (\levelheight * \mess@leveloffset)}%
    \msc@computelabelcoords%
    \msc@computelabelspec%
    \ifthenelse{\equal{\mess@style}{mess}}%
    {% THEN message arrow 
      \psline[linestyle=\mess@linestyle]{->}%
             (\tmp@Xa,-\tmp@Ya)%
             (\tmp@Xb,-\tmp@Yb)%
    }{%ELSE order arrow
      \setlength{\tmp@Xd}{.5\tmp@Xb + .5\tmp@Xa}%
      \setlength{\tmp@Yd}{.5\tmp@Yb + .5\tmp@Ya}%
      \psline[linestyle=\mess@linestyle]{->}%
             (\tmp@Xa,-\tmp@Ya)%
             (\tmp@Xd,-\tmp@Yd)%
      \psline[linestyle=\mess@linestyle]%
             (\tmp@Xd,-\tmp@Yd)%
             (\tmp@Xb,-\tmp@Yb)%
    }%
    \rput[\msc@labelrefpoint](\tmp@X,-\tmp@Y){\msc@labelbox{\mess@labeltext}}%
}%

\newcommand{\msc@computelabelcoords}{%
   \ifthenelse{%\equal{t}{t}%
               $\equal{\mess@sender}{\mess@receiver} \and \(\equal{\mess@labelposition}{l} \or%
                                                             \equal{\mess@labelposition}{r}$%
               \)%
               \or%
               $\not\(\equal{\mess@sender}{\mess@receiver}$ \and $\equal{\mess@labelposition}{t} \or%
                                                                     \equal{\mess@labelposition}{b}$%
               \)%
   }{% THEN
     \ifthenelse{\lengthtest{\tmp@Xa<\tmp@Xb}}%
     {% THEN
       \ifthenelse{\lengthtest{\tmp@Ya<\tmp@Yb}}%
       {% THEN
         \setlength{\tmp@X}{\tmp@Xa + (\tmp@Xb - \tmp@Xa)*\real{\mess@labelplacement}}%
         \setlength{\tmp@Y}{\tmp@Ya + (\tmp@Yb - \tmp@Ya)*\real{\mess@labelplacement}}%
       }{% ELSE
         \setlength{\tmp@X}{\tmp@Xa + (\tmp@Xb - \tmp@Xa)*\real{\mess@labelplacement}}%
         \setlength{\tmp@Y}{\tmp@Yb + (\tmp@Ya - \tmp@Yb) + (\tmp@Yb - \tmp@Ya)*\real{\mess@labelplacement}}%
       }%
     }{% ELSE
       \ifthenelse{\lengthtest{\tmp@Xa>\tmp@Xb}}%
       {% THEN 
         \ifthenelse{\lengthtest{\tmp@Ya<\tmp@Yb}}%
         {% THEN
           \setlength{\tmp@X}{\tmp@Xb + (\tmp@Xa - \tmp@Xb) + (\tmp@Xb - \tmp@Xa)*\real{\mess@labelplacement}}%
           \setlength{\tmp@Y}{\tmp@Ya + (\tmp@Yb - \tmp@Ya)*\real{\mess@labelplacement}}%
         }{% ELSE
           \setlength{\tmp@X}{\tmp@Xb + (\tmp@Xa - \tmp@Xb) + (\tmp@Xb - \tmp@Xa)*\real{\mess@labelplacement}}%
           \setlength{\tmp@Y}{\tmp@Yb + (\tmp@Ya - \tmp@Yb) + (\tmp@Yb - \tmp@Ya)*\real{\mess@labelplacement}}%
         }%
       }{% ELSE \tmpXa = \tmp@Xb (self message)
        \setlength{\tmp@X}{\tmp@Xa}%
        \ifthenelse{\lengthtest{\tmp@Ya<\tmp@Yb}}%
        {%
          \setlength{\tmp@Y}{\tmp@Ya + (\tmp@Yb - \tmp@Ya)*\real{\mess@labelplacement}}%
        }{%
          \setlength{\tmp@Y}{\tmp@Yb + (\tmp@Ya - \tmp@Yb) + (\tmp@Yb - \tmp@Ya)*\real{\mess@labelplacement}}}%
       }%
     }%
  }{% ELSE
    \msc@illegalmesslabelpositionerr{\mess@labelposition}%
  }
}

\newcommand{\msc@computelabelspec}{%
  \ifthenelse{\lengthtest{\tmp@Xa < \tmp@Xb}}%
    {% THEN  W->E
      \ifthenelse{\lengthtest{\tmp@Ya < \tmp@Yb}}%
        {% THEN NW->SE
          \ifthenelse{\equal{\mess@labelposition}{t}}%
            {\def\msc@labelrefpoint{Bl}
             \addtolength{\tmp@X}{\labeldist}%
             \addtolength{\tmp@Y}{-\labeldist}%
            }%
            {\def\msc@labelrefpoint{tr}
             \addtolength{\tmp@X}{-\labeldist}%
             \addtolength{\tmp@Y}{\labeldist}%
            }%
        }{% ELSE
          \ifthenelse{\lengthtest{\tmp@Ya > \tmp@Yb}}%
          {% THEN SW -> NE
            \ifthenelse{\equal{\mess@labelposition}{t}}%
              {\def\msc@labelrefpoint{Br}
             \addtolength{\tmp@X}{-\labeldist}%
             \addtolength{\tmp@Y}{-\labeldist}%
            }%
              {\def\msc@labelrefpoint{tl}
             \addtolength{\tmp@X}{\labeldist}%
             \addtolength{\tmp@Y}{\labeldist}%
            }%
          }{% ELSE W->E
          \ifthenelse{\equal{\mess@labelposition}{t}}%
            {\def\msc@labelrefpoint{B}
             \addtolength{\tmp@X}{0\labeldist}%
             \addtolength{\tmp@Y}{-\labeldist}%
            }%
            {\def\msc@labelrefpoint{t}
             \addtolength{\tmp@X}{0\labeldist}%
             \addtolength{\tmp@Y}{\labeldist}%
            }%
          }%
        }%
    }{% ELSE
      \ifthenelse{\lengthtest{\tmp@Xa > \tmp@Xb}}%
        {% THEN E -> W
        \ifthenelse{\lengthtest{\tmp@Ya < \tmp@Yb}}%
          {% THEN NE -> SW
          \ifthenelse{\equal{\mess@labelposition}{t}}%
            {\def\msc@labelrefpoint{Br}
             \addtolength{\tmp@X}{-\labeldist}%
             \addtolength{\tmp@Y}{-\labeldist}%
            }%
            {\def\msc@labelrefpoint{tl}
             \addtolength{\tmp@X}{\labeldist}%
             \addtolength{\tmp@Y}{\labeldist}%
            }%
          }{% ELSE
            \ifthenelse{\lengthtest{\tmp@Ya > \tmp@Yb}}%
            {% THEN SE -> NW
              \ifthenelse{\equal{\mess@labelposition}{t}}%
                {\def\msc@labelrefpoint{Bl}
             \addtolength{\tmp@X}{\labeldist}%
             \addtolength{\tmp@Y}{-\labeldist}%
            }%
                {\def\msc@labelrefpoint{tr}
             \addtolength{\tmp@X}{-\labeldist}%
             \addtolength{\tmp@Y}{\labeldist}%
            }%
            }{% ELSE E -> W
              \ifthenelse{\equal{\mess@labelposition}{t}}%
                {\def\msc@labelrefpoint{B}
             \addtolength{\tmp@X}{0\labeldist}%
             \addtolength{\tmp@Y}{-\labeldist}%
            }%
                {\def\msc@labelrefpoint{t}
             \addtolength{\tmp@X}{0\labeldist}%
             \addtolength{\tmp@Y}{\labeldist}%
            }%
            }
          }
        }{% ELSE \tmp@Xa = \tmp@Xb (self message)
          \ifthenelse{\equal{\mess@labelposition}{l}}%
            {\def\msc@labelrefpoint{r}
             \addtolength{\tmp@X}{-\labeldist}%
             \addtolength{\tmp@Y}{0\labeldist}%
            }%
            {\def\msc@labelrefpoint{l}
             \addtolength{\tmp@X}{\labeldist}%
             \addtolength{\tmp@Y}{0\labeldist}%
            }%
        }%
     }%
}%
\newcommand{\msc@labelbox}[1]{{#1}}%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Genralized orders
% \order[pos]{sender}{receiver}[leveloffset][instanceoffset]
%
\newcommand{\order}[3][l]{%
  \def\mess@style{order}%
  \def\mess@linestyle{dashed}%
  \def\selfmess@position{#1}%
  \def\mess@labelposition{\ifx\mess@sender\mess@receiver l\else t\fi}%
  \def\mess@labeltext{\relax}%
  \def\mess@labelplacement{0.5}%
  \def\mess@sender{#2}%
  \def\mess@receiver{#3}%
  \order@B%
}
\newcommand{\order@B}[1][\ifx\mess@sender\mess@receiver 1\else 0\fi]{%
  \edef\mess@leveloffset{#1}%
  \order@C%
}
\newcommand{\order@C}[1][0pt]{%
  \def\mess@instanceoffset{#1}%
  \msc@drawarrow%
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% LOST and FOUND messages
%
% \lost[pos]{label}[labelpos]{gate}{sender}[placement]
% \found[pos]{label}[labelpos]{gate}{sender}[placement]
\newcommand{\lost}[1][l]{%
  \def\lostfound@position{#1}%
  %\def\msc@arrowdirection{->}%
  \def\lostfound@type{lost}%
  \def\msc@circlefillstyle{black}%
  \lostfound@B%
}
\newcommand{\found}[1][l]{%
  \def\lostfound@position{#1}%
  %\def\msc@arrowdirection{<-}%
  \def\lostfound@type{found}%
  \def\msc@circlefillstyle{white}%
  \lostfound@B%
}
\newcommand{\lostfound@B}[1]{%
  \def\mess@style{mess}%
  \def\mess@labeltext{#1}%
  \lostfound@C%
}
\newcommand{\lostfound@C}[3][t]{%
  \def\mess@labelposition{#1}%
  \def\mess@gate{#2}%
  \def\mess@sender{#3}%
  \lostfound@D%
}
\newcommand{\lostfound@D}[1][0.5]{%
  \def\mess@labelplacement{#1}%
  \@lostfound%
}
%
% \@lostfound draws lost and found messages
\def\@lostfound{%
  \expandafter\@ifundefined{mscinst\mess@sender}{%
    \msc@instundefinederr{\mess@sender}}{% else, \mess@sender is defined
    %\setlength{\tmp@Xa}{\msc@instxpos{\mess@sender}}%
    \setlength{\tmp@Ya}{\msc@currentheight}%
    \ifthenelse{\equal{\lostfound@position}{l}}
    {% THEN put lost/found message left
      \ifthenelse{\equal{\lostfound@type}{lost}}%
        {% THEN
          \setlength{\tmp@Xa}% start of arrow
                    {\msc@instlxpos{\mess@sender}}%
          \setlength{\tmp@Xb}% end of arrow
                    {\tmp@Xa-\selfmesswidth}%
          \setlength{\tmp@X}% label position
                    {\tmp@Xb + (\tmp@Xa - \tmp@Xb) * \real{\mess@labelplacement}}%
          \setlength{\tmp@Xc}% circle position
                    {\tmp@Xb-\lostsymbolradius}%
        }{% ELSE
          \setlength{\tmp@Xb}% end of arrow
                    {\msc@instlxpos{\mess@sender}}%
          \setlength{\tmp@Xa}% start of arrow
                    {\tmp@Xb-\selfmesswidth}%
          \setlength{\tmp@X}% label position
                    {\tmp@Xa + (\tmp@Xb - \tmp@Xa) * \real{\mess@labelplacement}}%
          \setlength{\tmp@Xc}% circle position
                    {\tmp@Xa-\lostsymbolradius}%
        }%
        \setlength{\tmp@Xd}% gate position
                  {\tmp@Xc-\lostsymbolradius-\labeldist}%        
      \def\msc@gaterefpoint{r}%
    }{% ELSE, lost/found message right
      \ifthenelse{\equal{\lostfound@type}{lost}}%
        {% THEN
          \setlength{\tmp@Xa}% start of arrow
                    {\msc@instrxpos{\mess@sender}}%
          \setlength{\tmp@Xb}% end of arrow
                    {\tmp@Xa+\selfmesswidth}%
          \setlength{\tmp@X}% label position
                    {\tmp@Xa + (\tmp@Xb - \tmp@Xa) * \real{\mess@labelplacement}}%
          \setlength{\tmp@Xc}% circle position
                    {\tmp@Xb+\lostsymbolradius}%
        }{% ELSE
          \setlength{\tmp@Xb}% end of arrow
                    {\msc@instrxpos{\mess@sender}}%
          \setlength{\tmp@Xa}% start of arrow
                    {\tmp@Xb+\selfmesswidth}%
          \setlength{\tmp@X}% label position
                    {\tmp@Xb + (\tmp@Xa - \tmp@Xb) * \real{\mess@labelplacement}}%
          \setlength{\tmp@Xc}% circle position
                    {\tmp@Xa+\lostsymbolradius}%
        }%      
        \setlength{\tmp@Xd}% gate position
                  {\tmp@Xc+\lostsymbolradius+\labeldist}%
        \def\msc@gaterefpoint{l}%
    }%
    \psline{->}(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)%
    \ifthenelse{\equal{\mess@labelposition}{t}}%
      {% THEN
        \setlength{\tmp@Y}{\tmp@Ya-\lostsymbolradius-\labeldist}%
        \def\msc@labelrefpoint{B}%
      }{% ELSE
        \ifthenelse{\equal{\mess@labelposition}{b}}%
         {% THEN
          \setlength{\tmp@Y}{\tmp@Ya+\lostsymbolradius+\labeldist}%
          \def\msc@labelrefpoint{t}%
         }{% ELSE
          \msc@illegallostfoundlabelpositionerr{\mess@labelposition}%           
         }%
      }%
    \rput[\msc@labelrefpoint](\tmp@X,-\tmp@Y){\mess@labeltext}%
    \pscircle[fillstyle=solid,fillcolor=\msc@circlefillstyle]%
         (\tmp@Xc,-\tmp@Ya){\lostsymbolradius}
    \rput[\msc@gaterefpoint](\tmp@Xd,-\tmp@Ya){\mess@gate}%
  }%
}
%
%
% \settimer has one optional argument to define the position of
% the label of a self message.
\newcommand{\settimer}[1][l]{%
  \msc@settimerpos{#1}%
  \@timer{set}%
}
%
%
% \timeout has one optional argument to define the position of
% the label of a self message.
\newcommand{\timeout}[1][l]{%
  \msc@settimerpos{#1}%
  \@timer{timeout}%
}
%
%
% \stoptimer has one optional argument to define the position of
% the label of a self message.
\newcommand{\stoptimer}[1][l]{%
  \msc@settimerpos{#1}%
  \@timer{stop}%
}
%
%
% \settimeout has one optional argument to define the position of
% the label of a self message.
\newcommand{\settimeout}[1][l]{%
  \msc@settimerpos{#1}%
  \@timerdispatcher{settimeout}%
}
%
%
% \setstoptimer has one optional argument to define the position of
% the label of a self message.
\newcommand{\setstoptimer}[1][l]{%
  \msc@settimerpos{#1}%
  \@timerdispatcher{setstoptimer}%
}
\def\@timerdispatcher#1#2#3{%
  \@ifnextchar[{\@oargtimerdispatcher{#1}{#2}{#3}}{\@nooargtimerdispatcher{#1}{#2}{#3}}}
%
\def\@oargtimerdispatcher#1#2#3[#4]{%
  \msc@setleveloffset{#4}%
  \@timer{#1}{#2}{#3}%
}
%
\def\@nooargtimerdispatcher#1#2#3{%
  \msc@setleveloffset{2}% default level-offset value for combined timers
  \@timer{#1}{#2}{#3}%
}
%
%
% \@timer draws timers
% #1: type  of the timer (set/timeout/stop)
% #2: label
% #3: nickname of the instance
\def\@timer#1#2#3{%
  \expandafter\@ifundefined{mscinst#3}{%
    \msc@instundefinederr{#3}}{% else, #3 is defined
    \setlength{\tmp@Xa}{\msc@instxpos{#3}}%
    \setlength{\tmp@Ya}{\msc@currentheight}%
    \ifthenelse{\equal{\msc@timerpos}{l}}{% point left of axis
      \ifthenelse{\equal{\msc@instisfat{#3}}{true}}{%
        \setlength{\tmp@Xa}{\msc@instlxpos{#3}}%
      }{%
        \relax%
      }%
      \setlength{\tmp@Xb}{\tmp@Xa-\selfmesswidth}%
    }{ % else point right of axis
      \ifthenelse{\equal{\msc@instisfat{#3}}{true}}{%
        \setlength{\tmp@Xa}{\msc@instrxpos{#3}}%
      }{%
        \relax%
      }%
      \setlength{\tmp@Xb}{\tmp@Xa+\selfmesswidth}%
    }%
    \ifthenelse{\equal{#1}{timeout}}{% draw an arrow
      \psline{<-}(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)%
    }{ % else draw a line without arrow head
      \psline(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)%
    }%
    \setlength{\tmp@X}{\tmp@Xb}% This looks clumsy - sm
    \setlength{\tmp@Y}{\tmp@Ya}%
    \msc@drawtimer{#1}{\tmp@X}{\tmp@Y}{\msc@timerpos}{#2}%
    \ifthenelse{\equal{#1}{settimeout}}{% draw second part of settimeout
      \setlength{\tmp@Ya}{\tmp@Y+\levelheight*\msc@leveloffset}%
      \setlength{\tmp@Y}{\tmp@Y+0.75\timerwidth}%
      \setlength{\tmp@Xa}{\msc@instxpos{#3}}%
      \ifthenelse{\equal{\msc@timerpos}{l}}{% point left of axis
        \ifthenelse{\equal{\msc@instisfat{#3}}{true}}{%
          \setlength{\tmp@Xa}{\msc@instlxpos{#3}}%
        }{%
          \relax%
        }%
      }{ % else point right of axis
        \ifthenelse{\equal{\msc@instisfat{#3}}{true}}{%
          \setlength{\tmp@Xa}{\msc@instrxpos{#3}}%
        }{%
          \relax%
        }%
      }
      \psline{->}(\tmp@X,-\tmp@Y)(\tmp@X,-\tmp@Ya)(\tmp@Xa,-\tmp@Ya)%
    }{ % else not settimeout
      \ifthenelse{\equal{#1}{setstoptimer}}{% draw second part of setstoptimer
        \setlength{\tmp@Ya}{\tmp@Y+\levelheight*\msc@leveloffset}%
        \setlength{\tmp@Y}{\tmp@Y+0.75\timerwidth}% 
        \setlength{\tmp@Xb}{\msc@instxpos{#3}}%
        \ifthenelse{\equal{\msc@instisfat{#3}}{true}}{%
          \ifthenelse{\equal{\msc@timerpos}{l}}{% point left of axis
            \setlength{\tmp@Xb}{\msc@instlxpos{#3}}%
          }{% point right of axis
            \setlength{\tmp@Xb}{\msc@instrxpos{#3}}%
           }%
        }{% not a fat instance
          \relax%
        }
        \psline(\tmp@X,-\tmp@Y)(\tmp@X,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)%
        \setlength{\tmp@Y}{\tmp@Ya}%
        \msc@drawtimer{stop}{\tmp@X}{\tmp@Y}{\msc@timerpos}{}%
      }{ % else no second part needed
      }%
    }%
  }%
}
%
% \msc@drawtimer draws the timer symbols
% #1: type  of the timer (set/timeout/stop)
% #2: x-coordinate of center of timer
% #3: y-coordinate of center of timer
% #4: place text left (l) or right (r)
% #5: text added to the timer
\def\msc@drawtimer#1#2#3#4#5{%
  \setlength{\tmp@Xa}{#2-0.5\timerwidth}%
  \setlength{\tmp@Xb}{#2+0.5\timerwidth}%
  \ifthenelse{\equal{#1}{stop}}{% draw reset symbol
    \setlength{\tmp@Ya}{-#3+0.5\timerwidth}%
    \setlength{\tmp@Yb}{-#3-0.5\timerwidth}%
    \psline(\tmp@Xa,\tmp@Ya)(\tmp@Xb,\tmp@Yb)%
    \psline(\tmp@Xb,\tmp@Ya)(\tmp@Xa,\tmp@Yb)%
  }{% else draw set/timeout symbol
    \setlength{\tmp@Ya}{-#3+0.75\timerwidth}%
    \setlength{\tmp@Yb}{-#3-0.75\timerwidth}%
    \psline(\tmp@Xa,\tmp@Ya)(\tmp@Xb,\tmp@Yb)%
           (\tmp@Xa,\tmp@Yb)(\tmp@Xb,\tmp@Ya)(\tmp@Xa,\tmp@Ya)%
  }%
  \ifthenelse{\equal{#4}{l}}{% place label left
    \setlength{\tmp@Xa}{#2-\labeldist-0.3ex}%
    \setlength{\tmp@Ya}{-#3-0.5ex}%
    \rput[B](\tmp@Xa,\tmp@Ya){\makebox[0pt][r]{#5}}
  }{% else place label right
    \setlength{\tmp@Xa}{#2+\labeldist+0.3ex}%
    \setlength{\tmp@Ya}{-#3-0.5ex}%
    \rput[B](\tmp@Xa,\tmp@Ya){\makebox[0pt][l]{#5}}%
  }%
}
%
%
% \msc@drawinstancehead draws the head of the instance
% #1: nickname of the instance
\def\msc@drawinstancehead#1{%
  \setlength{\tmp@Y}{\msc@currentheight}%
  \msc@drawinstanceheadsymbol{#1}{\the\tmp@Y}%
}
%
% \msc@drawinstanceheadsymbol draw the head symbol of instance #1 at y-pos #2
\def\msc@drawinstanceheadsymbol#1#2{%
  \setlength{\tmp@X}{\msc@instxpos{#1}}% x-center head box
  \setlength{\tmp@Y}{#2 + 0.5\instheadheight}% center of head symbol
  \setlength{\tmp@Xa}{-0.5\instwidth+\tmp@X}% x-upperleft head box
  \setlength{\tmp@Ya}{#2}% y-upperleft head box
  \setlength{\tmp@Xb}{\tmp@Xa+\instwidth}% x-lowerright head box
  \setlength{\tmp@Yb}{#2 + \instheadheight}% y-lowerright head box
  \ifthenelse{\equal{\msc@insthead}{yes}}{%
    \psframe[dimen=middle,linestyle=\msc@instlinestyle{#1}](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
  }{% else, no head symbol drawing%
  }
  \rput[B](\tmp@X,-\tmp@Ya){\raisebox{\labeldist}{\makebox[0pt][c]{\msc@instabname{#1}}}}%
  \rput[B](\tmp@X,-\tmp@Y){\raisebox{-.5ex}{\makebox[0pt][c]{\msc@instinname{#1}}}}%  
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\def\msc@drawinstanceline#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
      \ifthenelse{\equal{\msc@instypos{#1}}{undefined}}{% y-pos undefined: no line needed
      }{% else
        \setlength{\tmp@Ya}{\msc@instypos{#1}}%
        \setlength{\tmp@Yb}{\msc@currentheight}%
        \ifthenelse{\equal{true}{\msc@instisfat{#1}}}%
          {% fat instance
           \setlength{\tmp@Xa}{\msc@instlxpos{#1}}%
           \setlength{\tmp@Xb}{\msc@instrxpos{#1}}%
           \ifthenelse{\equal{\msc@instregionstyle{#1}}{coregion}}
           {%
            \psline[linestyle=dashed](\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
            \psline[linestyle=dashed](\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
           }
           {\ifthenelse{\equal{\msc@instregionstyle{#1}}{suspension}}
            {%
             \psline[linestyle=dashed,dash=7pt 7pt](\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
             \psline[linestyle=dashed,dash=7pt 7pt](\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
            }
            {\ifthenelse{\equal{\msc@instregionstyle{#1}}{activation}}
             {%
              \psframe[dimen=middle,fillstyle=solid,fillcolor=lightgray](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)
              \psline[linestyle=solid](\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
              \psline[linestyle=solid](\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
             }
             {% normal region:
              \psline[linestyle=solid](\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
              \psline[linestyle=solid](\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
             }
            }
           }
          }
          {% normal instance (not fat)
           \setlength{\tmp@X}{\msc@instxpos{#1}}%
           \ifthenelse{\equal{\msc@instregionstyle{#1}}{coregion}}
           {%
            \psline[linestyle=dashed](\tmp@X,-\tmp@Ya)(\tmp@X,-\tmp@Yb)%
           }
           {\ifthenelse{\equal{\msc@instregionstyle{#1}}{suspension}}
            {%
             \setlength{\tmp@X}{\regionbarwidth}
             \setlength{\tmp@Xa}{\msc@instxpos{#1} - 0.5\tmp@X}%
             \setlength{\tmp@Xb}{\msc@instxpos{#1} + 0.5\tmp@X}%
             \psline[linestyle=dashed,dash=7pt 7pt](\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
             \psline[linestyle=dashed,dash=7pt 7pt](\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
            }
            {\ifthenelse{\equal{\msc@instregionstyle{#1}}{activation}}
             {%
              \setlength{\tmp@X}{\regionbarwidth}
              \setlength{\tmp@Xa}{\msc@instxpos{#1} - 0.5\tmp@X}%
              \setlength{\tmp@Xb}{\msc@instxpos{#1} + 0.5\tmp@X}%
              \psframe[dimen=middle,fillstyle=solid,fillcolor=lightgray](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)
              \psline[linestyle=solid](\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
              \psline[linestyle=solid](\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
             }
             {% normal region
              \psline[linestyle=\msc@instlinestyle{#1}](\tmp@X,-\tmp@Ya)(\tmp@X,-\tmp@Yb)%
             }
            }
           }
          }%
     }%
  }%
}%
%
% \msc@drawinstancefoot draws the last level and foot of the instance
% #1: nickname of the instance
\def\msc@drawinstancefoot#1{%
    \setlength{\tmp@Y}{\msc@currentheight}%
    \msc@drawinstancefootsymbol{#1}{\the\tmp@Y}%
}
%
% \msc@drawinstancefootsymbol draws a footer symbol for instance #1 at y-pos #2.
\def\msc@drawinstancefootsymbol#1#2{%
  \setlength{\tmp@Xa}{-0.5\instwidth+\msc@instxpos{#1}}%
  \setlength{\tmp@Ya}{\msc@currentheight}%
  \setlength{\tmp@Xb}{\tmp@Xa+\instwidth}%
  \setlength{\tmp@Yb}{#2 + \instfootheight}%
  \ifthenelse{\equal{\msc@instfoot}{yes}}{
    \psframe[dimen=middle,fillstyle=solid,fillcolor=\msc@instfootcolor{#1},linestyle=\msc@instlinestyle{#1}](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
  }{% else, no foot symbol drawing%
  }
}
%
% \nextlevel incresaes \msc@currentheight by #1 * \levelheight
% (optional) #1: a nonnegative integer number (defaults to 1)
% 
\newcommand{\nextlevel}[1][1]{%
  \addtolength{\msc@currentheight}{#1\levelheight}%
}
%
\def\msc@drawinstancefooters{%
  \ifthenelse{\value{tmpcnt} < \value{mscinstcnt}}{%
     % Only draw the instancefoot if the instypos is defined (not ``undefined'')
     % This signals a previous instance stop.
     \ifthenelse{\equal{\msc@instypos{\msc@instnickname{tmpcnt}}}{undefined}}{\relax}{%
      \msc@drawinstanceline{\msc@instnickname{tmpcnt}}%
      \msc@drawinstancefoot{\msc@instnickname{tmpcnt}}%
    }%
    \msc@incrcounter{tmpcnt}%
    \msc@drawinstancefooters}{% else nothing
    }%
}%
%
% \action puts an action symbol on the instance with nickname #2.
% The action symbol will be placed on the current level and the text #1
% is centered inside the action symbol.
\def\action#1#2{%
  \expandafter\@ifundefined{mscinst#2}{%
    \msc@instundefinederr{#2}}{% else, #2 is defined
    % first, draw the instance line as far as possible
    \msc@drawinstanceline{#2}%
    % then, draw the action symbol
    % if #2's bar width is greater than the action width, the width of this
    % action will be the instnce bar width.
    \ifthenelse{\lengthtest{\msc@instbarwidth{#2}<\actionwidth}}%
      {\setlength{\tmp@X}{\actionwidth}}%
      {\setlength{\tmp@X}{\msc@instbarwidth{#2}}}%
    \setlength{\tmp@Xa}{\msc@instxpos{#2}-0.5\tmp@X}%
    \setlength{\tmp@Xb}{\tmp@Xa+\tmp@X}%
    \setlength{\tmp@Ya}{\msc@currentheight}%
    \setlength{\tmp@Yb}{\tmp@Ya+\actionheight}%
    \psframe[dimen=middle](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
    \setlength{\tmp@X}{\msc@instxpos{#2}}%
    \setlength{\tmp@Y}{\tmp@Ya+0.5\actionheight}%
    \rput[B](\tmp@X,-\tmp@Y){\raisebox{-.5ex}{\makebox[0pt][c]{#1}}}%
    % redefine the instance's y position
    \setlength{\tmp@Y}{\msc@currentheight+\actionheight}%
    \msc@setinstypos{#2}{\the\tmp@Y}%
  }%
}
%
% \stop ends the instance with nickname #1.
\def\stop#1{%
  \expandafter\@ifundefined{mscinst#1}{%
    \msc@instundefinederr{#1}}{% else, #1 is defined
    % first, draw the instance line as far as possible
    \msc@drawinstanceline{#1}%
    \setlength{\tmp@Yb}{\msc@currentheight}%
    % close the instance axis if it is a fat instance
    \ifthenelse{\equal{true}{\msc@instisfat{#1}}}%
      {%
       \setlength{\tmp@Xa}{\msc@instlxpos{#1}}%
       \setlength{\tmp@Xb}{\msc@instrxpos{#1}}%
       \psline(\tmp@Xa,-\tmp@Yb)(\tmp@Xb,-\tmp@Yb)%
      }%
      {% else it is not fat
      }% 
    % then, draw the stop symbol
    \setlength{\tmp@X}{\msc@instxpos{#1}}%
    \setlength{\tmp@Xa}{\tmp@X-0.5\stopwidth}%
    \setlength{\tmp@Xb}{\tmp@X+0.5\stopwidth}%
    \setlength{\tmp@Ya}{\tmp@Yb+0.5\stopwidth}%
    \setlength{\tmp@Yb}{\tmp@Yb-0.5\stopwidth}%
    \psline(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)%
    \psline(\tmp@Xb,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)%
    % redefine the instance's y position
    % ``undefined'' means that the instance axis will not be drawn any further
    \msc@setinstypos{#1}{undefined}%
  }%
}
%
%
% \condition puts a condition symbol over the given instances
% #1: name to be put inside the condition symbol
% #2: comma-separated list of instance nicknames, such that:
%     - The first instance nickname is supposed to be the leftmost 
%       instance of the condition
%     - The last instance nickname is supposed to be the rightmost
%       instance of the condition
\def\condition#1#2{%
  \def\msc@conditiontext{#1}%
  \def\msc@firstconditioninst{undefined}%
  \def\msc@lastconditioninst{undefined}%
  \msc@condition{#2}%
% debugging info:
%  \message{(msc: condition: \msc@firstconditioninst...\msc@lastconditioninst)}%
  \ifthenelse{\equal{\msc@instisfat{\msc@firstconditioninst}}{true}}{%
      \setlength{\tmp@Xa}{\msc@instlxpos{\msc@firstconditioninst}-\conditionoverlap}%
    }{%
      \setlength{\tmp@Xa}{\msc@instxpos{\msc@firstconditioninst}-\conditionoverlap}%
    }%
  \setlength{\tmp@Ya}{\msc@currentheight}%
  \ifthenelse{\equal{\msc@instisfat{\msc@lastconditioninst}}{true}}{%
      \setlength{\tmp@Xb}{\msc@instrxpos{\msc@lastconditioninst}+\conditionoverlap}%
    }{%
      \setlength{\tmp@Xb}{\msc@instxpos{\msc@lastconditioninst}+\conditionoverlap}%
    }%
  \setlength{\tmp@Yb}{\tmp@Ya+\conditionheight}%
  \msc@drawcondition{#1}{\tmp@Xa}{\tmp@Ya}{\tmp@Xb}{\tmp@Yb}%
}
%
\def\msc@condition#1{%
  \@for\msccondition@rg:=#1\do{%
    \expandafter\@ifundefined{mscinst\msccondition@rg}{%
      \msc@instundefinederr{\msccondition@rg}}{% else, \msccondition@rg is defined
% debugging info:
%     \message{(msc: condition instance "\msccondition@rg")}%
      \ifthenelse{\equal{\msc@firstconditioninst}{undefined}}{%
        \edef\msc@firstconditioninst{\msccondition@rg}%
      }{\ifthenelse{\lengthtest{\msc@instxpos{\msc@firstconditioninst} > \msc@instxpos{\msccondition@rg}}}{%
          \edef\msc@firstconditioninst{\msccondition@rg}}{}%
      }%
      \ifthenelse{\equal{\msc@lastconditioninst}{undefined}}{%
        \edef\msc@lastconditioninst{\msccondition@rg}%
      }{\ifthenelse{\lengthtest{\msc@instxpos{\msc@lastconditioninst} < \msc@instxpos{\msccondition@rg}}}{%
          \edef\msc@lastconditioninst{\msccondition@rg}}{}%
      }
      % now, draw the instance line as far as possible
      \msc@drawinstanceline{\msccondition@rg}%
  %    \setlength{\tmp@X}{\msc@instxpos{\msccondition@rg}}%
  %    \setlength{\tmp@Ya}{\msc@instypos{\msccondition@rg}}%
  %    \setlength{\tmp@Yb}{\msc@currentheight+\msc@headoffset}%
  %    \psline[linestyle=\msc@instlinestyle{\msccondition@rg}](\tmp@X,-\tmp@Ya)(\tmp@X,-\tmp@Yb)%
      % and redefine the instance's y position
      \setlength{\tmp@Y}{\msc@currentheight+\conditionheight}%
      \msc@setinstypos{\msccondition@rg}{\the\tmp@Y}% 
    }%
  }%
}
%
% \msc@drawcondition draw the condition symbol
% #1: condition-text
\def\msc@drawcondition#1#2#3#4#5{%
  \setlength{\tmp@Xc}{#4+ .6#5 - .6#3}%
  \setlength{\tmp@Yc}{.5#3 + .5#5}%
  \psline(#2,-#3)(#4,-#3)(\tmp@Xc,-\tmp@Yc)(#4,-#5)%
  \setlength{\tmp@Xc}{#2- .6#5 + .6#3}%
  \psline(#4,-#5)(#2,-#5)(\tmp@Xc,-\tmp@Yc)(#2,-#3)%
  \setlength{\tmp@Xc}{.5#2 + .5#4}%
  \setlength{\tmp@Yc}{.5#3 + .5#5}%
  \rput[B](\tmp@Xc,-\tmp@Yc){\raisebox{-.5ex}{\makebox[0pt][c]{#1}}}%
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%   GATES
% \gate[hpos][vpos]{text}{nickname}[h-offset]
% \gate*[hpos][vpos]{text}{nickname}[h-offset] 
%   (starred version puts a dot at the position of the gate on the instance line)
%
% hpos: optional horizontal position argument l(eft) or r(ight). default: l
% vpos: optional vertical position argument t(op), c(enter) or b(ottom). default: t
% text: text to be placed at the gate
% nickname: nickname of the instance to which the gate belongs
% 
\def\gate{\@ifstar{\def\msc@gatestar{defined}\msc@gateh}{\def\msc@gatestar{undefined}\msc@gateh}}
\newcommand{\msc@gateh}[1][l]{%
  \def\msc@gatehpos{#1}%
  \msc@gatev%
}
%
\newcommand{\msc@gatev}[3][t]{%
  \msc@gate{#1}{#2}{#3}%
}
%
\def\msc@gate#1#2#3{%
  \expandafter\@ifundefined{mscinst#3}{%
    \msc@instundefinederr{#3}}{% else, #3 is defined
    \ifthenelse{\equal{\msc@instisfat{#3}}{true}}
      {\ifthenelse{\equal{\msc@gatehpos}{l}}
        {\setlength{\tmp@X}{\msc@instlxpos{#3}}}
        {\setlength{\tmp@X}{\msc@instrxpos{#3}}}
      }%
      {\setlength{\tmp@X}{\msc@instxpos{#3}}}
    \ifthenelse{\equal{\msc@gatestar}{defined}}{%
      \setlength{\tmp@Y}{\msc@currentheight}%
      \pscircle[fillstyle=solid,fillcolor=black](\tmp@X,-\tmp@Y){.5mm}}{}%
    \ifthenelse{\equal{t}{#1}}{
      \setlength{\tmp@Y}{\msc@currentheight - \labeldist}%
      \def\msc@gatetext{{#2}}%
    }{%
    \ifthenelse{\equal{c}{#1}}{%
      \setlength{\tmp@Y}{\msc@currentheight}%
      \def\msc@gatetext{\raisebox{-.5\totalheight}{#2}}%
    }{%
      \setlength{\tmp@Y}{\msc@currentheight + \labeldist}%
      \def\msc@gatetext{\raisebox{-\totalheight}{#2}}%
    }}%
    \ifthenelse{\equal{l}{\msc@gatehpos}}{%
      \addtolength{\tmp@X}{-\labeldist}%
      \rput[B](\tmp@X,-\tmp@Y){\makebox[0pt][r]{\msc@gatetext}}}%
    {%
      \addtolength{\tmp@X}{\labeldist}%
      \rput[B](\tmp@X,-\tmp@Y){\makebox[0pt][l]{\msc@gatetext}}%
    }%
  }
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% MSC COMMENTS
%
%
% \msccomment[#1]{#2}{#3}
% #1: position l/r or a distance
% #2: text
% #3: instance nick name
\newcommand{\msccomment}[3][l]{%
   \expandafter\@ifundefined{mscinst#3}{%
     \msc@instundefinederr{#3}}
     {% else, #3 is defined
     \ifthenelse{\equal{#1}{l}}%
       {\setlength{\msc@commentdist}{-\msccommentdist}}%
       {\ifthenelse{\equal{#1}{r}}%
         {\setlength{\msc@commentdist}{\msccommentdist}}%
         {\setlength{\msc@commentdist}{#1}}%
       }
     \savebox{\tmp@box}{\raisebox{\depth}[\totalheight][0pt]{#2}}%
     \setlength{\tmp@Y}{\msc@currentheight}%
     \setlength{\tmp@Ya}{\tmp@Y + .5\ht\tmp@box}%
     \addtolength{\tmp@Ya}{\labeldist}%
     \setlength{\tmp@Yb}{\tmp@Y - .5\ht\tmp@box}%
     \addtolength{\tmp@Yb}{-\labeldist}%
%     \message{( a: \the\tmp@Ya, b: \the\tmp@Yb)}
     \ifthenelse{\lengthtest{\msc@commentdist < 0pt}}%
       {% comment left from instance #3
        \setlength{\tmp@X}{\msc@instlxpos{#3}}
        \setlength{\tmp@Xa}{\tmp@X + \msc@commentdist}
        \psline(\tmp@X,-\tmp@Y)(\tmp@Xa,-\tmp@Y)
        \psline(\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)
        \setlength{\tmp@Xb}{\wd\tmp@box}
        \setlength{\tmp@Xb}{\tmp@Xa - \tmp@Xb}
        \addtolength{\tmp@Xb}{-\labeldist}
        \psline(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)
        \psline(\tmp@Xa,-\tmp@Yb)(\tmp@Xb,-\tmp@Yb)
        \addtolength{\tmp@Xa}{-\labeldist}
        \rput[r](\tmp@Xa,-\tmp@Y){#2}%
       }%
       {% comment right from instance #3
        \setlength{\tmp@X}{\msc@instrxpos{#3}}
        \setlength{\tmp@Xa}{\tmp@X + \msc@commentdist}
        \psline(\tmp@X,-\tmp@Y)(\tmp@Xa,-\tmp@Y)
        \psline(\tmp@Xa,-\tmp@Ya)(\tmp@Xa,-\tmp@Yb)
        \setlength{\tmp@Xb}{\wd\tmp@box}
        \setlength{\tmp@Xb}{\tmp@Xa + \tmp@Xb}
        \addtolength{\tmp@Xb}{\labeldist}
        \psline(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)
        \psline(\tmp@Xa,-\tmp@Yb)(\tmp@Xb,-\tmp@Yb)
        \addtolength{\tmp@Xa}{\labeldist}
        \rput[l](\tmp@Xa,-\tmp@Y){\usebox{\tmp@box}}
       }%
    }%
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% MSC MARKS
%
% \mark[#1]{#2}{#3}
% #1: placement: tl,bl,tr,br
% #2: text
% #3: instance nick name
%
\newcommand{\mscmark}[3][tl]{%
   \expandafter\@ifundefined{mscinst#3}{%
     \msc@instundefinederr{#3}}
     {% else, #3 is defined
     \savebox{\tmp@box}{\raisebox{\depth}[\totalheight][0pt]{#2}}
     \ifthenelse{\equal{#1}{tl}}
     {%tl:
       \setlength{\tmp@X}{\msc@instlxpos{#3}}
       \setlength{\tmp@Xa}{\tmp@X - \markdist}
       \setlength{\tmp@Xb}{\tmp@Xa - \wd\tmp@box - 2\labeldist}
       \setlength{\tmp@Y}{\msc@currentheight}
       \setlength{\tmp@Ya}{\msc@currentheight - .5\markdist}
       \psline[linestyle=dashed](\tmp@X,-\tmp@Y)(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)
       \setlength{\tmp@Xb}{\tmp@Xa - \labeldist - .5\wd\tmp@box}
       \addtolength{\tmp@Ya}{-\labeldist}
       \rput[b](\tmp@Xb,-\tmp@Ya){\usebox{\tmp@box}}
     }{
     \ifthenelse{\equal{#1}{bl}}
     {%tl:
       \setlength{\tmp@X}{\msc@instlxpos{#3}}
       \setlength{\tmp@Xa}{\tmp@X - \markdist}
       \setlength{\tmp@Xb}{\tmp@Xa - \wd\tmp@box - 2\labeldist}
       \setlength{\tmp@Y}{\msc@currentheight}
       \setlength{\tmp@Ya}{\msc@currentheight + .5\markdist}
       \psline[linestyle=dashed](\tmp@X,-\tmp@Y)(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)
       \setlength{\tmp@Xb}{\tmp@Xa - \labeldist - .5\wd\tmp@box}
       \addtolength{\tmp@Ya}{-\labeldist}
       \rput[b](\tmp@Xb,-\tmp@Ya){\usebox{\tmp@box}}
     }{
     \ifthenelse{\equal{#1}{tr}}
     {%bl:
       \setlength{\tmp@X}{\msc@instrxpos{#3}}
       \setlength{\tmp@Xa}{\tmp@X + \markdist}
       \setlength{\tmp@Xb}{\tmp@Xa + \wd\tmp@box + 2\labeldist}
       \setlength{\tmp@Y}{\msc@currentheight}
       \setlength{\tmp@Ya}{\msc@currentheight - .5\markdist}
       \psline[linestyle=dashed](\tmp@X,-\tmp@Y)(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)
       \setlength{\tmp@Xb}{\tmp@Xa + \labeldist + .5\wd\tmp@box}
       \addtolength{\tmp@Ya}{-\labeldist}
       \rput[b](\tmp@Xb,-\tmp@Ya){\usebox{\tmp@box}}
     }{
     \ifthenelse{\equal{#1}{br}}
     {%tl:
       \setlength{\tmp@X}{\msc@instrxpos{#3}}
       \setlength{\tmp@Xa}{\tmp@X + \markdist}
       \setlength{\tmp@Xb}{\tmp@Xa + \wd\tmp@box + 2\labeldist}
       \setlength{\tmp@Y}{\msc@currentheight}
       \setlength{\tmp@Ya}{\msc@currentheight + .5\markdist}
       \psline[linestyle=dashed](\tmp@X,-\tmp@Y)(\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)
       \setlength{\tmp@Xb}{\tmp@Xa + \labeldist + .5\wd\tmp@box}
       \addtolength{\tmp@Ya}{-\labeldist}
       \rput[b](\tmp@Xb,-\tmp@Ya){\usebox{\tmp@box}}
     }{
     \msc@illegalmarkplacement{#1}
     }}}}}
}
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% MSC MEASURES
%
%
\newlength{\msc@measuredist}% internal length for horizontal measure distance
% \measure[*][#1]{#2}{#3}{#4}[#5]
% *: the starred version puts the top measure mark above and the bottom measure mark
%    below the measure position.
% #1: placement: l (left) r (right), or distance (negative or positive) to closest of #3 or #4
% #2: name
% #3: instance nick name
% #4: instance nick name
% #5: (vertical) offset
\newcommand{\measure}{%
  \@ifstar{\def\msc@innermeasure{false}\msc@measureargs}
          {\def\msc@innermeasure{true}\msc@measureargs}% 
}
%
\newcommand{\msc@measureargs}[4][l]{%
  \def\msc@i{#1}%
  \def\msc@ii{#2}%
  \def\msc@iii{#3}%
  \def\msc@iv{#4}%
  \msc@measureoffset%
}

\newcommand{\msc@measureoffset}[1][1]{%
  \def\msc@mscv{#1}%
  \msc@measure{\msc@i}{\msc@ii}{\msc@iii}{\msc@iv}{\msc@mscv}
}

\newcommand{\msc@measure}[5]{%
  \ifthenelse{\equal{#1}{l}}
    {\setlength{\msc@measuredist}{-\measuredist}}
    {\ifthenelse{\equal{#1}{r}}
       {\setlength{\msc@measuredist}{\measuredist}}
       {\setlength{\msc@measuredist}{#1}}}
    %
    \setlength{\tmp@Ya}{\msc@currentheight}
    \setlength{\tmp@Yb}{\tmp@Ya + #5\levelheight}
    \setlength{\tmp@Y}{.5\tmp@Ya + .5\tmp@Yb}
    \ifthenelse{\lengthtest{\msc@instxpos{#3} < \msc@instxpos{#4}}}
      {% 
      \ifthenelse{\lengthtest{\msc@measuredist < 0pt}}
        {% left from instances
          \setlength{\tmp@Xa}{\msc@instlxpos{#3}}
          \setlength{\tmp@Xb}{\msc@instlxpos{#4}}
          \setlength{\tmp@X}{\tmp@Xa + \msc@measuredist}
        }
        {% right from instances
          \setlength{\tmp@Xa}{\msc@instrxpos{#3}}
          \setlength{\tmp@Xb}{\msc@instrxpos{#4}}
          \setlength{\tmp@X}{\tmp@Xb + \msc@measuredist}
        }
      }
      {% 
      \ifthenelse{\lengthtest{\msc@measuredist < 0pt}}
        {% left from instances
          \setlength{\tmp@Xa}{\msc@instlxpos{#3}}
          \setlength{\tmp@Xb}{\msc@instlxpos{#4}}
          \setlength{\tmp@X}{\tmp@Xb + \msc@measuredist}
        }
        {% right from instances
          \setlength{\tmp@Xa}{\msc@instrxpos{#3}}
          \setlength{\tmp@Xb}{\msc@instrxpos{#4}}
          \setlength{\tmp@X}{\tmp@Xa + \msc@measuredist}
        }
      }
    \psline[linestyle=dashed](\tmp@Xa,-\tmp@Ya)(\tmp@X,-\tmp@Ya)(\tmp@X,-\tmp@Yb)(\tmp@Xb,-\tmp@Yb)
    \ifthenelse{\lengthtest{\msc@measuredist < 0pt}}
      {% left from instances
      \addtolength{\tmp@X}{-\labeldist}
      \rput[r](\tmp@X,-\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{#2}}
      \addtolength{\tmp@X}{\labeldist}
      }
      {% right from instances
      \addtolength{\tmp@X}{\labeldist}
      \rput[l](\tmp@X,-\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{#2}}
      \addtolength{\tmp@X}{-\labeldist}
      }
    \ifthenelse{\equal{\msc@innermeasure}{true}}
      {%
       \msc@measuresymbolup{\tmp@X}{\tmp@Ya}
       \msc@measuresymboldown{\tmp@X}{\tmp@Yb}
      }
      {%
       \msc@measuresymboldown{\tmp@X}{\tmp@Ya}
       \msc@measuresymbolup{\tmp@X}{\tmp@Yb}
      }
}
%
%
% \measurestart[*][#1]{#2}{#3}{#4}
% *: unstarred/starred version draws downward/upward triangle
% #1: placement: l (left) r (right), or distance (negative or positive) to  #3
% #2: name
% #3: instance nick name
% #4: gate name
\newcommand{\measurestart}{%
  \@ifstar{\def\msc@innermeasure{false}\msc@measurestartargs}
          {\def\msc@innermeasure{true}\msc@measurestartargs}
}
%
%
\newcommand{\msc@measurestartargs}[4][l]{%
  \def\msc@i{#1}%
  \def\msc@ii{#2}%
  \def\msc@iii{#3}%
  \def\msc@iv{#4}%
  \msc@measurestartoffset%
}

\newcommand{\msc@measurestartoffset}[1][2]{%
  \msc@measurestart{\msc@i}{\msc@ii}{\msc@iii}{\msc@iv}{#1}%
}
%
\newcommand{\msc@measurestart}[5]{%
  \ifthenelse{\equal{#1}{l}}
    {\setlength{\msc@measuredist}{-\measuredist}}
    {\ifthenelse{\equal{#1}{r}}
       {\setlength{\msc@measuredist}{\measuredist}}
       {\setlength{\msc@measuredist}{#1}}}
  \setlength{\tmp@Ya}{\msc@currentheight}
  \ifthenelse{\lengthtest{\msc@measuredist < 0pt}}
    {% left from instance
    \setlength{\tmp@Xa}{\msc@instlxpos{#3}}
    \setlength{\tmp@Xb}{\tmp@Xa + \msc@measuredist}
    \setlength{\tmp@Yb}{\tmp@Ya + #5\levelheight}
    \setlength{\tmp@X}{\tmp@Xb - \labeldist - 0.5\measuresymbolwidth}
    \setlength{\tmp@Y}{.5\tmp@Ya + .5\tmp@Yb}
    \rput[r](\tmp@X,-\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{#2}}
    \setlength{\tmp@Y}{\tmp@Yb + \labeldist}
    \rput[r](\tmp@X,-\tmp@Yb){\raisebox{\depth}[\totalheight][0pt]{#4}}
    }
    {% right from instance
    \setlength{\tmp@Xa}{\msc@instrxpos{#3}}
    \setlength{\tmp@Xb}{\tmp@Xa + \msc@measuredist}
    \setlength{\tmp@Yb}{\tmp@Ya + #5\levelheight}
    \setlength{\tmp@X}{\tmp@Xb + \labeldist + 0.5\measuresymbolwidth}
    \setlength{\tmp@Y}{.5\tmp@Ya + .5\tmp@Yb}
    \rput[l](\tmp@X,-\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{#2}}
    \setlength{\tmp@Y}{\tmp@Yb + \labeldist}
    \rput[l](\tmp@X,-\tmp@Yb){\raisebox{\depth}[\totalheight][0pt]{#4}}
    }
   \psline[linestyle=dashed](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)
   \ifthenelse{\equal{\msc@innermeasure}{true}}
     {\msc@measuresymbolup{\tmp@Xb}{\tmp@Ya}}
     {\msc@measuresymboldown{\tmp@Xb}{\tmp@Ya}}
   \rput(\tmp@Xb,-\tmp@Yb){\pscircle[fillcolor=white,fillstyle=solid](0,0){.5\measuresymbolwidth}}
 } 
%
% \measureend[*][#1]{#2}{#3}{#4}
% *: unstarred/starred version draws upward/downward triangle
% #1: placement: l (left) r (right), or distance (negative or positive) to  #3
% #2: name
% #3: instance nick name
% #4: gate name
\newcommand{\measureend}{%
  \@ifstar{\def\msc@innermeasure{false}\msc@measureendargs}%
          {\def\msc@innermeasure{true}\msc@measureendargs}%
}
%
\newcommand{\msc@measureendargs}[4][l]{%
  \def\msc@i{#1}%
  \def\msc@ii{#2}%
  \def\msc@iii{#3}%
  \def\msc@iv{#4}%
  \msc@measureendoffset%
}  
%
\newcommand{\msc@measureendoffset}[1][2]{%
  \msc@measureend{\msc@i}{\msc@ii}{\msc@iii}{\msc@iv}{#1}%
}
%
\newcommand{\msc@measureend}[5]{%
  \ifthenelse{\equal{#1}{l}}
    {\setlength{\msc@measuredist}{-\measuredist}}
    {\ifthenelse{\equal{#1}{r}}
       {\setlength{\msc@measuredist}{\measuredist}}
       {\setlength{\msc@measuredist}{#1}}}
  \setlength{\tmp@Ya}{\msc@currentheight}
  \ifthenelse{\lengthtest{\msc@measuredist < 0pt}}
    {% left from instance
    \setlength{\tmp@Xa}{\msc@instlxpos{#3}}
    \setlength{\tmp@Xb}{\tmp@Xa + \msc@measuredist}
    \setlength{\tmp@Yb}{\tmp@Ya - #5\levelheight}
    \setlength{\tmp@X}{\tmp@Xb - \labeldist - 0.5\measuresymbolwidth}
    \setlength{\tmp@Y}{.5\tmp@Ya + .5\tmp@Yb}
    \rput[r](\tmp@X,-\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{#2}}
    \setlength{\tmp@Y}{\tmp@Yb - \labeldist}
    \rput[r](\tmp@X,-\tmp@Yb){\raisebox{\depth}[\totalheight][0pt]{#4}}
    }
    {% right from instance
    \setlength{\tmp@Xa}{\msc@instrxpos{#3}}
    \setlength{\tmp@Xb}{\tmp@Xa + \msc@measuredist}
    \setlength{\tmp@Yb}{\tmp@Ya - #5\levelheight}
    \setlength{\tmp@X}{\tmp@Xb + \labeldist + 0.5\measuresymbolwidth}
    \setlength{\tmp@Y}{.5\tmp@Ya + .5\tmp@Yb}
    \rput[l](\tmp@X,-\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{#2}}
    \setlength{\tmp@Y}{\tmp@Yb - \labeldist}
    \rput[l](\tmp@X,-\tmp@Yb){\raisebox{\depth}[\totalheight][0pt]{#4}}
    }
   \psline[linestyle=dashed](\tmp@Xa,-\tmp@Ya)(\tmp@Xb,-\tmp@Ya)(\tmp@Xb,-\tmp@Yb)
   \ifthenelse{\equal{\msc@innermeasure}{true}}
     {\msc@measuresymboldown{\tmp@Xb}{\tmp@Ya}}
     {\msc@measuresymbolup{\tmp@Xb}{\tmp@Ya}}
   \rput(\tmp@Xb,-\tmp@Yb){\pscircle[fillcolor=white,fillstyle=solid](0,0){.5\measuresymbolwidth}}
 } 
%
% measure symbols
%
\def\msc@measuresymbolup#1#2{%
  % sin(pi/3) =~  0.866025403784
  % draw an upward triangle with 60-degree (pi/3) angles and base at (#1,#2)
  \rput[t](#1,-#2){%
    \begin{pspicture}(-1,0)(1,0.866025403784\measuresymbolwidth)%
      \pstriangle[dimen=middle,fillcolor=white,fillstyle=solid](\measuresymbolwidth,0.866025403784\measuresymbolwidth)%
    \end{pspicture}%
  }
}
%	
\def\msc@measuresymboldown#1#2{%
  % sin(pi/3) =~  0.866025403784
  % draw a downward triangle with 60-degree (pi/3) angles and base at (#1,#2)
  \rput[b](#1,-#2){%
    \begin{pspicture}(-1,0)(1,-0.866025403784\measuresymbolwidth)%
      \pstriangle[dimen=middle,fillcolor=white,fillstyle=solid](\measuresymbolwidth,-0.866025403784\measuresymbolwidth)%
    \end{pspicture}%
  }
}

%	
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \drawmscframe draws a frame of the right size around the msc
% This command also set the value of \msc@totalsizebox
\def\msc@drawframe{%
  \ifthenelse{\equal{\msc@frame}{yes}}{%
    \psframe[dimen=middle](0,0)(\msc@currentwidth,-\msc@currentheight)%
  }{% no frame drawing
  }%
}
%
% \msckeyword is the keyword representation of msc
\def\msckeyword{msc}
\def\msckeywordstyle#1{\textbf{#1}}
%
% This keyword can be changed by the \setmsckeyword command (or by \renewcommand{\msckeyword}{...}):
\newcommand{\setmsckeyword}[1]{\def\msckeyword{#1}}
\newcommand{\setmsckeywordstyle}[1]{\def\msckeywordstyle{#1}}%
%
% Commands to switch internal options that control the drawing of header and footer symbols
\newcommand{\drawinsthead}[1]{\def\msc@insthead{#1}}% 
\drawinsthead{yes}%
\newcommand{\drawinstfoot}[1]{\def\msc@instfoot{#1}}% 
\drawinstfoot{yes}%
% A similar command to control drawing of the msc-frame
\newcommand{\drawframe}[1]{\def\msc@frame{#1}}% 
\drawframe{yes}%
%
%
\def\msc@grid{no}%
\newcommand{\showgrid}{\def\msc@grid{yes}}
\newcommand{\nogrid}{\def\msc@grid{no}}

\def\msc@settitle{%
\MSC@settitle{msc}%
               {0\mscunit}%
               {-\msc@totalheight}%
               {\msc@totalwidth}%
               {0\mscunit}%
               {\msc@titlejustification}%
               {\msckeywordstyle{\msckeyword}{} \msc@title}%
}

%
% \msc@title stores the title given in \begin{msc}{title}
\def\msc@title{}%
%
% \msc@titlejustification says how the title should be justified
% Justification is relative to the total width of the msc 
% l: left (default)
% c: centered
% r: right
%
\newsavebox{\mscbox}%
%
% the msc-environment
\newenvironment{msc}[2][l]{%
\message{(\msckeyword: '#2'}%
\def\msc@titlejustification{#1}%
\def\msc@title{#2}%
\setcounter{mscinstcnt}{0}%
\setlength{\msc@currentheight}{\topheaddist}%
\addtolength{\msc@currentheight}{\instheadheight}%
\addtolength{\msc@currentheight}{\firstlevelheight}%
\setlength{\msc@currentwidth}{0pt}%
% define the artificial left and right environment instances
\msc@declinst{envleft}{}{}{\the\instbarwidth}%
\msc@setinstxpos{envleft}{0pt}%
\msc@declinst{envright}{}{}{\the\instbarwidth}%
\msc@setinstxpos{envright}{\envinstdist}%
\begin{lrbox}{\mscbox}%
\begin{pspicture}(0,0)% we draw the msc in a picture of size 0x0
\psset{dash=4pt 4pt}% sets the hashed linestyle style
}{%
 \addtolength{\msc@currentheight}{\lastlevelheight}%
 \setcounter{tmpcnt}{2}%
 \msc@drawinstancefooters%
% If there is at least one instance, the current width is 
% set to the xpos of the NEXT msc instance. There is at least one instance,
% if mscinstcnt >= 2. So, in that case, we have to 
% substract one \instdist from the current width.
%
%\ifthenelse{\value{mscinstcnt}<2}{% no user defined instances, so, relax
%  \relax%
%}{% mscinstcnt >= 2
%  \addtolength{\msc@currentwidth}{-\instdist}%
%}%
% Now we compute the final current width: one extra \envinstdist:
\setlength{\msc@currentwidth}{\msc@instxpos{envright}}%
\addtolength{\msc@currentheight}{\instfootheight+\bottomfootdist}%
\msc@drawframe%
\global\msc@totalwidth=\msc@currentwidth%
\global\msc@totalheight=\msc@currentheight%
\ifthenelse{\equal{\msc@grid}{yes}}{%
   \psgrid[subgriddiv=1,griddots=10](0,0)(0,0)(\msc@currentwidth,-\msc@currentheight)%
}{\relax}%
\msc@settitle%
\end{pspicture}% 
% Debug info:
%\typeout{msc size: \the\msc@totalwidth x\the\msc@totalheight}%
\end{lrbox}%
% the \mscbox now contains a box of 0x0, however the actual width and
% height are stored in \msc@total{width,height}. We use these lengths
% to adjust the width and height of the \mscbox
\wd\mscbox=\msc@totalwidth%
\ht\mscbox=\msc@totalheight%
\dp\mscbox=0pt%
% Now the \mscbox can be scaled (by \mscscalefactor) and `printed':
{% DEBUG: use this \fbox stuf to check the bounding box 
 \setlength{\fboxrule}{0.01pt}%
 \setlength{\fboxsep}{1pt}%
 \color{white}\fbox{%
   \scalebox{\mscscalefactor}{\raisebox{\msc@totalheight}[\msc@totalheight][0pt]{\usebox{\mscbox}}}%
 }%
}%
\message{)}%
}%
%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\newcommand{\MSC@settitle}[7]{%
  % #1: diagram type (msc, mscdoc, hmsc)
  % #2: llx
  % #3: lly
  % #4: urx
  % #5: ury
  % #6: justification (l, c, r)
  % #7: typeset title
  \setlength{\tmp@X}{#4 - #2 - 2\leftnamedist}%
  \ifthenelse{\equal{#6}{l}}%
  {%
   \def\MSC@dosettitle{\parbox[t]{\tmp@X}{\raggedright #7}}% 
  }%
  {\ifthenelse{\equal{#6}{c}}%
   {%
    \def\MSC@dosettitle{\parbox[t]{\tmp@X}{\centering #7}}%    
   }%
   {\ifthenelse{\equal{#6}{r}}%
    {%
     \def\MSC@dosettitle{\parbox[t]{\tmp@X}{\raggedleft #7}}%
    }%
    {\msc@illegaltitleplacement{#6}}%
   }%
  }%  
  \setlength{\tmp@Y}{#5 - \topnamedist}%
  \setlength{\tmp@Xb}{#2 + \leftnamedist}%
  \rput[tl](\tmp@Xb,\tmp@Y){\MSC@dosettitle}%    
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%                           MSC documents
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% \mscdockeyword is the keyword representation of msc
\def\mscdockeyword{mscdoc}
\def\mscdockeywordstyle#1{\textbf{#1}}
%
% This keyword can be changed by the \setmscdockeyword command (or by \renewcommand{\mscdockeyword}{...}):
\newcommand{\setmscdockeyword}[1]{\def\mscdockeyword{#1}}
\newcommand{\setmscdockeywordstyle}[1]{\def\mscdockeywordstyle{#1}}%

\newcommand{\mscdoc@settitle}{%
  \MSC@settitle{mscdoc}%
               {\mscdoc@llx}%
               {\mscdoc@lly}%
               {\mscdoc@urx}%
               {\mscdoc@ury}%
               {\mscdoc@titlejustification}%
               {\mscdockeywordstyle{\mscdockeyword}{} \mscdoc@title}%
}

\newenvironment{mscdoc}[2][l]%
{%
 \message{( \mscdockeyword: '#2'}%
 \def\mscdoc@titlejustification{#1}%
 \def\mscdoc@title{#2}%
 \def\reference##1(##2,##3){%
  \setlength{\tmp@X}{\mscdocreferencewidth}%
  \setlength{\tmp@Y}{\mscdocreferenceheight}%
  \def\txt{\vbox to \tmp@Y{\vss\hbox to \tmp@X{\hss{}##1\hss}\vss}}%
  \rput(##2\mscunit,##3\mscunit){\psframebox[%
   framearc=0.25,%
   framesep=0pt,%
   border=0pt%
  ]{\txt}}}%
 \def\separator##1{%
  \psline[linestyle=dashed](\mscdoc@llx,##1)(\mscdoc@urx,##1)
 }%
 \def\mscdoc@sizespec(##1,##2)(##3,##4)%
 {%
  \def\mscdoc@llx{##1\mscunit}%
  \def\mscdoc@lly{##2\mscunit}%
  \def\mscdoc@urx{##3\mscunit}%
  \def\mscdoc@ury{##4\mscunit}%
\begin{lrbox}{\mscbox}%
  \begin{pspicture}(\mscdoc@llx,\mscdoc@lly)(\mscdoc@urx,\mscdoc@ury)%
    \ifthenelse{\equal{\msc@grid}{yes}}{%
      \psgrid[subgriddiv=1,griddots=10](\mscdoc@llx,\mscdoc@lly)(\mscdoc@urx,\mscdoc@ury)%
    }{\relax}%
    \ifthenelse{\equal{\msc@frame}{yes}}{%
      \psframe(\mscdoc@llx,\mscdoc@lly)(\mscdoc@urx,\mscdoc@ury)%
    }{\relax}%
    \mscdoc@settitle%
 }%
 \mscdoc@sizespec%
}%
{%
 \end{pspicture}%
\end{lrbox}%
{% DEBUG: use this \fbox stuf to check the bounding box 
 \setlength{\fboxrule}{0.01pt}%
 \setlength{\fboxsep}{1pt}%
 \color{white}\fbox{%
  \usebox{\mscbox}%
  }%
}%
 \message{)}%
}

%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%                           HMSC
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\RequirePackage{pst-node}

\newcommand{\hmsckeyword}{hmsc}
\newcommand{\hmsckeywordstyle}[1]{\textbf{#1}}

% This keyword can be changed by the \sethmsckeyword command (or by \renewcommand{\hmsckeyword}{...}):
\newcommand{\sethmsckeyword}[1]{\def\hmsckeyword{#1}}
\newcommand{\sethmsckeywordstyle}[1]{\def\hmsckeywordstyle{#1}}%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\newif\if@ncsegline

%
% User command to draw a segmented line between two nodes (buggy).
%
% NOTE: this implementation is not complete yet. The optional arrows argument
%       only makes sense for forward arrows (and even then in a limited way).
% usage: \ncsegline[settings]{arrows}{#1}[(x0,y0)...(xn,xy)]{#2}
%  settings (optional): pstricks settings for lines
%  arrows(optional): pstricks-style arrow defintions
%  #1: start node
%  (x0,y0)...(xn,yn) (optional): sequence of intermediate points  
%  #2: end node 
\def\ncsegline{%
  \@ifstar{\def\@nclinecommand{\ncline*}\@ncseglinei}{\def\@nclinecommand{\ncline}\@ncseglinei}%
}

\def\ncseglinecheck@arrow#1#2{%
  \ncseglinecheck@@arrow#2-\@nil
  \if@ncsegline%
%    \message{(arrow: `#2')}%
    \edef\@ncseglinearrow{{#2}}%
    \def\next{#1}%
  \else%
%    \message{(no arrow `#2')}%
    \edef\@ncseglinearrow{{-}}%
    \def\next{#1{#2}}%
  \fi%
  \next%
}

\def\ncseglinecheck@@arrow#1-#2\@nil{%
\ifx\@nil#2\@nil\@ncseglinefalse\else\@ncseglinetrue\fi}

\def\@ncseglinei{%
  \@ifnextchar[{\@ncseglineReadSettings}{\def\@nclinesettings{[]}\ncseglinecheck@arrow{\@ncseglineii}}%]
}

\def\@ncseglineReadSettings[#1]{%
  \def\@nclinesettings{[#1]}%
  \ncseglinecheck@arrow{\@ncseglineii}%
}

\def\@ncseglineii#1{%
  \def\@ncsegargA{#1}%
  \@ifnextchar[{\@ncseglineiii}{\@ncseglineiv}%
}

\def\@ncseglineiii[#1]#2{%
  \@ncseglineA#1(\relax,\relax)%
  \def\@ncsegargB{#2}%
  \@ncseglinedraw%
}

\def\@ncseglineiv#1{%
  \def\@ncsegargB{#1}%
  \@ncseglinedraw%
}

\def\@ncseglinedraw{%
  \edef\@ncseglineattrs{\@nclinesettings\@ncseglinearrow}%
  \expandafter\@nclinecommand\@ncseglineattrs{\@ncsegargA}{\@ncsegargB}%
}

\def\@ncseglineA(#1,#2){%
  \ifx#1\relax%
    \def\next{\relax}%
  \else%
%    \message{(line seg)}%
    \pnode(#1,#2){#1#2}%
    \expandafter\@nclinecommand\@nclinesettings{-}{\@ncsegargA}{#1#2}%
    \edef\@ncsegargA{#1#2}%
    \def\next{\@ncseglineA}%
  \fi
  \next%
}

% User command to draw hmsc start symbols
% usage: \hmscstartsymbol{#1}(#2,#3)
%   #1: nickname
%   #2: x-coordinate
%   #3: y-coordinate
%
%
% sin(pi/3) =~ 0.866025403784
% 
\def\hmscstartsymbol#1(#2,#3){%
  %\message{(hmsc start symbol: #1)}%
  \setlength{\tmp@Xa}{#2\mscunit}%
  \setlength{\tmp@Ya}{#3\mscunit}%
  \setlength{\tmp@Xb}{\tmp@Xa}\addtolength{\tmp@Xb}{-.5\hmscstartsymbolwidth}%
  \setlength{\tmp@Xc}{\tmp@Xa}\addtolength{\tmp@Xc}{.5\hmscstartsymbolwidth}%
  \setlength{\tmp@Yb}{\tmp@Ya}\addtolength{\tmp@Yb}{0.866025403784\hmscstartsymbolwidth}%
  \pspolygon(\tmp@Xa,\tmp@Ya)(\tmp@Xb,\tmp@Yb)(\tmp@Xc,\tmp@Yb)%
  \pnode(#2,#3){#1}%
}

% User command to draw hmsc end symbols
% usage: \hmscendsymbol{#1}(#2,#3)
%   #1: nickname
%   #2: x-coordinate
%   #3: y-coordinate
%
%
% sin(pi/3) =~ 0.866025403784
% 
\def\hmscendsymbol#1(#2,#3){%
  %\message{(hmsc end symbol: #1)}%
  \setlength{\tmp@Xa}{#2\mscunit}%
  \setlength{\tmp@Ya}{#3\mscunit}%
  \setlength{\tmp@Xb}{\tmp@Xa}\addtolength{\tmp@Xb}{-.5\hmscstartsymbolwidth}%
  \setlength{\tmp@Xc}{\tmp@Xa}\addtolength{\tmp@Xc}{.5\hmscstartsymbolwidth}%
  \setlength{\tmp@Yb}{\tmp@Ya}\addtolength{\tmp@Yb}{-0.866025403784\hmscstartsymbolwidth}%
  \pspolygon(\tmp@Xa,\tmp@Ya)(\tmp@Xb,\tmp@Yb)(\tmp@Xc,\tmp@Yb)%
  \pnode(#2,#3){#1}%
}

% User command to draw a hmsc condition
% usage: \hmsccondition{#1}{#2}(#3,#4)
%   #1: nickname
%   #2: text
%   #3: x-coordinate
%   #4: y-coordinate
\def\hmsccondition#1#2(#3,#4){%
  \setlength{\tmp@X}{.5\hmscconditionwidth}%
  \setlength{\tmp@Y}{.5\hmscconditionheight}%
  \setlength{\tmp@Xa}{\tmp@X}\addtolength{\tmp@Xa}{.6\tmp@Y}%
  \rput(#3\mscunit,#4\mscunit){%
    \pspolygon(-\tmp@X,\tmp@Y)%
              (\tmp@X,\tmp@Y)%
              (\tmp@Xa,0)%
              (\tmp@X,-\tmp@Y)%
              (-\tmp@X,-\tmp@Y)%
              (-\tmp@Xa,0)}%
  \setlength{\tmp@X}{\hmscconditionwidth}%
  \setlength{\tmp@Y}{\hmscconditionheight}%
  \def\ctxt{\vbox to \tmp@Y{\vss\hbox to \tmp@X{\hss{}#2\hss}\vss}}%
  \rput(#3\mscunit,#4\mscunit){\rnode{#1}{\psframebox[%
   linestyle=none,%
   linewidth=0pt,%
   framesep=0pt,%
   border=0pt%
  ]{\ctxt}}}%
}

% User command to draw a hmsc reference
% usage: \hmscreference{#1}{#2}(#3,#4)
%   #1: nickname
%   #2: text
%   #3: x-coordinate
%   #4: y-coordinate
\def\hmscreference#1#2(#3,#4){%
  \setlength{\tmp@X}{\hmscreferencewidth}%
  \setlength{\tmp@Y}{\hmscreferenceheight}%
  \def\rtxt{\vbox to \tmp@Y{\vss\hbox to \tmp@X{\hss{}#2\hss}\vss}}%
  \rput(#3\mscunit,#4\mscunit){\rnode{#1}{\psframebox[%
   framearc=0.25,%
   framesep=0pt,%
   border=0pt%
  ]{\rtxt}}}%
}

% User command to draw hmsc connections
% usage: \hmscconnection{#1}(#2,#3)
%  #1: nickname
%  #2: x-coordinate
%  #3: y-coordinate
\def\hmscconnection#1(#2,#3){%
  \rput(#2,#3){\circlenode[framesep=0pt]{#1}{\rule{0pt}{2\hmscconnectionradius}}}%
}

% User command to draw arrows between hmsc-objects
% Usage: \arrow{#1}[(x0,y0)...(xn,yn)]{#2}
%   #1: start hmsc object
%   (x0,y0)...(xn,yn) (optional): sequence of intermediate points
%   #2: end hmsc object
\newcommand{\arrow}{
  \ncsegline{->}%
}

% User environment to draw hmsc's
% Usage: \begin{hmsc}{#1}(llx,lly((urx,ury)...\end{hmsc}
%

\def\hmsc@settitle{%
  \MSC@settitle{hmsc}%
               {\hmsc@llx}%
               {\hmsc@lly}%
               {\hmsc@urx}%
               {\hmsc@ury}%
               {\hmsc@titlejustification}%
               {\hmsckeywordstyle{\hmsckeyword}{} \hmsc@title}%
%  \setlength{\tmp@X}{\hmsc@llx + \leftnamedist}%
%  \setlength{\tmp@Y}{\hmsc@ury - \topnamedist}%
%  \rput[tl](\tmp@X,\tmp@Y){%
%    \hmsckeywordstyle{\hmsckeyword}{} \hmsc@title%
%  }%
}

\newenvironment{hmsc}[2][l]
  {\message{( \hmsckeyword: '#2'}%
   \def\hmsc@titlejustification{#1}%
   \def\hmsc@title{#2}%
   \hmsc@startenv}%
  {%\setlength{\tmp@X}{\hmsc@llx}\addtolength{\tmp@X}{\leftnamedist}%
   %\setlength{\tmp@Y}{\hmsc@ury}\addtolength{\tmp@Y}{-\topnamedist}%
   %\rput[tl](\tmp@X,\tmp@Y){\raisebox{\depth}[\totalheight][0pt]{\hmsckeywordstyle{\hmsckeyword} \hmsc@name}}%
   \hmsc@settitle%
   \ifthenelse{\equal{\msc@frame}{yes}}{%
     \psframe(\hmsc@llx,\hmsc@lly)(\hmsc@urx,\hmsc@ury)%
   }{\relax}%
   \end{pspicture}%
\end{lrbox}%
{% DEBUG: use this \fbox stuf to check the bounding box 
 \setlength{\fboxrule}{0.01pt}%
 \setlength{\fboxsep}{1pt}%
 \color{white}\fbox{%
  \usebox{\mscbox}%
  }%
}%
   \message{)}}%
\def\hmsc@startenv(#1,#2)(#3,#4){%
  \newcommand{\hmsc@llx}{#1\mscunit}%
  \newcommand{\hmsc@lly}{#2\mscunit}%
  \newcommand{\hmsc@urx}{#3\mscunit}%
  \newcommand{\hmsc@ury}{#4\mscunit}%
\begin{lrbox}{\mscbox}%
  \begin{pspicture}(\hmsc@llx,\hmsc@lly)(\hmsc@urx,\hmsc@ury)%
    \ifthenelse{\equal{\msc@grid}{yes}}{%
      \psgrid[subgriddiv=1,griddots=10](\hmsc@llx,\hmsc@lly)(\hmsc@urx,\hmsc@ury)%
    }{\relax}%
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Initialisation of the msc package
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% \set@mscvalueslarge 
\def\set@mscvalueslarge{%
  \psset{linewidth=0.8pt}
  % the lengths
  \setlength{\actionheight}{0.75\mscunit}
  \setlength{\actionwidth}{1.25\mscunit}
  \setlength{\bottomfootdist}{1\mscunit}
  \setlength{\msccommentdist}{1.5\mscunit}
  \setlength{\conditionheight}{0.75\mscunit}
  \setlength{\conditionoverlap}{0.6\mscunit}
  \setlength{\envinstdist}{2.5\mscunit} 
  \setlength{\firstlevelheight}{0.75\mscunit} 
  \setlength{\hmscconditionheight}{0.8\mscunit}
  \setlength{\hmscconditionwidth}{1.6\mscunit}
  \setlength{\hmscconnectionradius}{0.06\mscunit}
  \setlength{\hmscreferenceheight}{0.8\mscunit}
  \setlength{\hmscreferencewidth}{1.6\mscunit}
  \setlength{\hmscstartsymbolwidth}{0.85\mscunit}
  \setlength{\inlineoverlap}{1.5\mscunit}
  \setlength{\instbarwidth}{0pt}
  \setlength{\instdist}{3\mscunit} 
  \setlength{\instfootheight}{0.25\mscunit} 
  \setlength{\instheadheight}{.6\mscunit} 
  \setlength{\instwidth}{1.75\mscunit} 
  \setlength{\labeldist}{1ex}
  \setlength{\lastlevelheight}{0.5\mscunit} 
  \setlength{\leftnamedist}{0.3\mscunit}
  \setlength{\levelheight}{.75\mscunit} 
  \setlength{\lostsymbolradius}{.15\mscunit}
  \setlength{\markdist}{1\mscunit}
  \setlength{\measuredist}{0.75\mscunit}
  \setlength{\measuresymbolwidth}{.15\mscunit}
  \setlength{\mscdocreferenceheight}{0.8\mscunit}
  \setlength{\mscdocreferencewidth}{1.6\mscunit}
  \setlength{\referenceoverlap}{1.5\mscunit}
  \setlength{\regionbarwidth}{.5\mscunit}
  \setlength{\selfmesswidth}{.75\mscunit}
  \setlength{\stopwidth}{0.6\mscunit}
  \setlength{\timerwidth}{0.4\mscunit}
  \setlength{\topheaddist}{1.5\mscunit}
  \setlength{\topnamedist}{.3\mscunit}
  % some numeric parameters
  \messarrowscale{2}
}
%
%
% \set@mscvaluesnormal 
\def\set@mscvaluesnormal{%
  \psset{linewidth=0.7pt}
  % switch to a smaller font
  \small% 
  % the lengths
  \setlength{\actionheight}{0.6\mscunit}
  \setlength{\actionwidth}{1.25\mscunit}
  \setlength{\bottomfootdist}{0.7\mscunit}
  \setlength{\msccommentdist}{1.1\mscunit}
  \setlength{\conditionheight}{0.6\mscunit}
  \setlength{\conditionoverlap}{0.5\mscunit}
  \setlength{\envinstdist}{2\mscunit} 
  \setlength{\firstlevelheight}{0.6\mscunit} 
  \setlength{\hmscconditionheight}{0.7\mscunit}
  \setlength{\hmscconditionwidth}{1.4\mscunit}
  \setlength{\hmscconnectionradius}{0.05\mscunit}
  \setlength{\hmscreferenceheight}{0.7\mscunit}
  \setlength{\hmscreferencewidth}{1.4\mscunit}
  \setlength{\hmscstartsymbolwidth}{0.7\mscunit}
  \setlength{\inlineoverlap}{1\mscunit}
  \setlength{\instbarwidth}{0pt} 
  \setlength{\instdist}{2.2\mscunit} 
  \setlength{\instfootheight}{0.2\mscunit} 
  \setlength{\instheadheight}{.55\mscunit} 
  \setlength{\instwidth}{1.6\mscunit} 
  \setlength{\labeldist}{1ex}
  \setlength{\lastlevelheight}{0.4\mscunit} 
  \setlength{\leftnamedist}{0.2\mscunit}
  \setlength{\levelheight}{.5\mscunit} 
  \setlength{\lostsymbolradius}{.12\mscunit}
  \setlength{\markdist}{1\mscunit}
  \setlength{\measuredist}{0.6\mscunit}
  \setlength{\measuresymbolwidth}{.2\mscunit}
  \setlength{\mscdocreferenceheight}{0.7\mscunit}
  \setlength{\mscdocreferencewidth}{1.4\mscunit}
  \setlength{\referenceoverlap}{1\mscunit}
  \setlength{\regionbarwidth}{.4\mscunit}
  \setlength{\selfmesswidth}{.6\mscunit}
  \setlength{\stopwidth}{0.5\mscunit}
  \setlength{\timerwidth}{0.3\mscunit}
  \setlength{\topheaddist}{1.3\mscunit}
  \setlength{\topnamedist}{.2\mscunit}
  % some numeric parameters
  \messarrowscale{1.5}
}
%
% \set@mscvaluessmall
\def\set@mscvaluessmall{%
  \psset{linewidth=0.6pt}
  % switch to a smaller font
  \small% 
  % the lengths
  \setlength{\actionheight}{0.5\mscunit}
  \setlength{\actionwidth}{1.2\mscunit}
  \setlength{\bottomfootdist}{0.5\mscunit}
  \setlength{\msccommentdist}{0.75\mscunit}
  \setlength{\conditionheight}{0.5\mscunit}
  \setlength{\conditionoverlap}{0.4\mscunit}
  \setlength{\envinstdist}{1.2\mscunit} 
  \setlength{\firstlevelheight}{0.4\mscunit} 
  \setlength{\hmscconditionheight}{0.6\mscunit}
  \setlength{\hmscconditionwidth}{1.2\mscunit}
  \setlength{\hmscconnectionradius}{0.04\mscunit}
  \setlength{\hmscreferenceheight}{0.6\mscunit}
  \setlength{\hmscreferencewidth}{1.2\mscunit}
  \setlength{\hmscstartsymbolwidth}{0.4\mscunit}
  \setlength{\inlineoverlap}{.75\mscunit}
  \setlength{\instbarwidth}{0pt} 
  \setlength{\instdist}{1.5\mscunit} 
  \setlength{\instfootheight}{0.15\mscunit} 
  \setlength{\instheadheight}{0.5\mscunit} 
  \setlength{\instwidth}{1.2\mscunit} 
  \setlength{\labeldist}{0.8ex}
  \setlength{\lastlevelheight}{0.3\mscunit} 
  \setlength{\leftnamedist}{0.1\mscunit}
  \setlength{\levelheight}{0.4\mscunit} 
  \setlength{\lostsymbolradius}{.08\mscunit}
  \setlength{\markdist}{1\mscunit}
  \setlength{\measuredist}{0.4\mscunit}
  \setlength{\measuresymbolwidth}{.25\mscunit}
  \setlength{\mscdocreferenceheight}{0.6\mscunit}
  \setlength{\mscdocreferencewidth}{1.2\mscunit}
  \setlength{\referenceoverlap}{.75\mscunit}
  \setlength{\regionbarwidth}{.2\mscunit}
  \setlength{\selfmesswidth}{.4\mscunit}
  \setlength{\stopwidth}{0.3\mscunit}
  \setlength{\timerwidth}{0.2\mscunit}
  \setlength{\topheaddist}{1.2\mscunit}
  \setlength{\topnamedist}{.1\mscunit}
  % some numeric parameters
  \messarrowscale{1.2}
}
% \setmscvalues assigns compatible values to all msc-parameters 
% Currently, three sets of values are supported: large, normal
% and small.
\def\setmscvalues#1{%
  \ifthenelse{\equal{#1}{large}}{%
    \set@mscvalueslarge}{%
  \ifthenelse{\equal{#1}{normal}}{%
    \set@mscvaluesnormal}{%
  \ifthenelse{\equal{#1}{small}}{%
    \set@mscvaluessmall}{%
  \ifthenelse{\equal{#1}{measure}}{%
    \set@mscvaluesmeasure}{%
  \msc@unknownmscvalueserr{#1}}}}}%
}
%
% initialisation of the msc-parameters
\setmscvalues{normal}
\setfootcolor{black}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Error and help messages
% We use the standard LaTeX2e facilities to generate error and help
% messages (for more info, see file lterror.dtx of LaTeX2e distribution).
%
%
% nickname already defined
\gdef\msc@nicknamedefinederr#1{%
  \PackageError{msc}{% error message
    nickname #1 already defined}{% help text
    You tried to use the nickname '#1' for a new\MessageBreak
    msc object (instance, reference, inline expression, etc.),\MessageBreak
    but the nickname is already assigned to another msc object.\MessageBreak
    press <enter> to continue (the new msc object will be ignored).}%
}
%
% no such msc instance error
\gdef\msc@instundefinederr#1{%
  \PackageError{msc}{% error message
    undefined msc instance: #1}{% help text
    You used '#1' as an msc instance nickname, but\MessageBreak
    there is no msc instance with that nickname.}%
}
%
% unknown linestyle error
\gdef\msc@unknownlinestyleerr#1{%
  \PackageError{msc}{% error message
    unknown linestyle: #1}{% help text
    Known msc linestyles are "solid", "dashed", and "dotted".\MessageBreak
    You used '#1'.}%
}
%
% unknown region style error
\gdef\msc@unknownregionstyleerr#1{%
  \PackageError{msc}{% error message
    unknown region style: #1}{% help text
    Known msc region styles are "normal", "coregion", "suspension", and "activation".\MessageBreak
    You used '#1'.}%
}
%
% unknown self message label position error
\gdef\msc@unknownselfmessposerr#1{%
  \PackageError{msc}{% error message
    unknown position for self message: #1}{% help text
    Known positions are "l" (left), "r" (right).\MessageBreak
    You used '#1'.}%
}
%
% unknown self message label position error
\gdef\msc@unknowntimerposerr#1{%
  \PackageError{msc}{% error message
    unknown timer position: #1}{% help text
    Known timer positions are "l" (left), "r" (right).\MessageBreak
    You used '#1'.}%
}
%
% unknown self message label position error
\gdef\msc@unknownmscvalueserr#1{%
  \PackageError{msc}{% error message
    unknown set of msc-values: #1}{% help text
    Known sets of msc-values are "normal" and "small".\MessageBreak
    You used '#1'.}%
}
%
% no such msc reference error
\gdef\msc@refundefinederr#1{%
  \PackageError{msc}{% error message
    undefined reference: #1}{% help text
    You used '#1' as a reference nickname, but\MessageBreak
    there is no reference with that nickname.}%
}
%
% no such msc inline error
\gdef\msc@inlundefinederr#1{%
  \PackageError{msc}{% error message
    undefined inline expression: #1}{% help text
    You used '#1' as a inline expression nickname, but\MessageBreak
    there is no inline expression with that nickname.}%
}
%
% inline first right from last error
\gdef\msc@inlfirstlasterror#1#2#3{%
  \PackageError{msc}{% error message
    first instance right from final instance\MessageBreak in inline expression #1}{% help text
    In the definition of inline expression '#1', you probably switched\MessageBreak 
    the first msc instance, '#2', and the final msc instance, '#3',\MessageBreak
    since the first is located right from the final.}%
}
%
% reference first rightt from last error
\gdef\msc@reffirstlasterror#1#2#3{%
  \PackageError{msc}{% error message
    first instance right from final instance\MessageBreak in reference #1}{% help text
    In the definition of msc reference '#1', you probably switched\MessageBreak 
    the first msc instance, '#2', and the final msc instance, '#3',\MessageBreak
    since the first is located right from the final.}%
}
%
\gdef\msc@illegalmarkplacement#1{%
  \PackageError{msc}{%
    illegal mark placement specifier: #1}{% help text
    The four mark placement specifiers are:\MessageBreak
      tl (top-left)\MessageBreak
      bl (bottom-left)\MessageBreak
      tr (top-right)\MessageBreak
      br (bottom-right)}
}
\gdef\msc@illegalmesslabelpositionerr#1{%
  \PackageError{msc}{%
    illegal label position specifier: #1}{% help text
    Valid label position specifiers are:\MessageBreak
      t (top)\MessageBreak
      b (bottom)}
}
\gdef\msc@illegalselfmesspositionerr#1{%
  \PackageError{msc}{%
    illegal label position: #1}{% help text
    Valid label positions are:\MessageBreak
      t (top)\MessageBreak
      b (bottom)\MessageBreak
      l (left)\MessageBreak
      r (right)}
}
\gdef\msc@illegallostfoundlabelpositionerr#1{%
  \PackageError{msc}{%
    in lost/found message: illegal label position: #1}{% help text
    Valid label position are:\MessageBreak
      t (top)\MessageBreak
      b (bottom)}
}
%################################################################################
%
\gdef\msc@illegaltitleplacement#1{%
  \PackageError{msc}{%
    illegal title placement specifier: #1}{% help text
    Valid title placement specifiers are:\MessageBreak
      l (left)\MessageBreak
      c (center)\MessageBreak
      r (right)}
}
%################################################################################
\gdef\hmsc@nicknamedefinederr#1{%
  \PackageError{msc}{% error message
    nickname #1 already defined}{% help text
    You tried to use the nickname '#1' for a new\MessageBreak
    hmsc object (startsymbol, endsymbol, reference, etc.),\MessageBreak
    but the nickname is already assigned to another hmsc object.\MessageBreak
    press <enter> to continue (the new hmsc object will be ignored).}%
}
% no such msc hmsc object error
\gdef\hmsc@objectundefinederr#1{%
  \PackageError{msc}{% error message
    undefined hmsc object: #1}{% help text
    You used '#1' as an hmsc object nickname, but\MessageBreak
    there is no hmsc object with that nickname.}%
}%
% hmsc unknown connection type
\gdef\hmsc@unknownconnectiontypeerror#1{%
  \PackageError{msc}{% error message
    Unknown HMSC connection type: #1}{% help text
    Known HMSC connection types are straight, rounded, and curved.}%
}
%
% hmsc missing y coordinate in arrow specification
\gdef\hmsc@missingycoord#1#2{%
  \PackageError{msc}{% error message
  Missing Y coordinate in arrow specification. You typed:\MessageBreak
  [#2]\MessageBreak
  which is parsed as the incomplete list of points:\MessageBreak
  #1\MessageBreak
  Remove the final X coordinate or add an Y coordinate}{%
  The points specifying an HMSC arrow should be given as a comma separated\MessageBreak
  list of X, Y coordinates. Furthermore, each X coordinate should\MessageBreak
  be followed by a Y coordinate.}%
} 
% remarks
% 
% Issuing pstricks drawing-commands inside a TeX-group in a pspicture environment
% can result in ill-positioned objects.
%
% messages from/to the right environment should be defined after the last
% instance is declared with \declinst

${this.title}

Code Editor : msc.sty