% This is (almost) exact copy of 
% fp-basic.sty package (Michael Mehlich)
% 
% It is patched to work with multido.sty
% FPadd -> FPfadd
% FPsub -> FPfsub

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{pstfp}[2003/05/10]



%version information
\def\FP@basicversion{1.2d}
\message{%
  `(Patched) Basic Fixed Point Arithmetic',\space\space%

  Version \FP@basicversion%
  \space(C) Michael Mehlich%

  \space Patched by R. Stepanyan%
  \space\space\space\space\space\space\space%
  \space\space\space\space\space\space%
}

%fixed point arithmetic with values between (including)
%      -999999999999999999.999999999999999999
% and  +999999999999999999.999999999999999999


% to suppress messages
\let\FP@save@message\message
\def\message#1{}


%%%public area (macros which may be used)%%%

%introduce and print new values
\def\FPset#1#2{\FP@set[#1|#2]}
\def\FPprint#1{\FP@print[#1]}

%binary operations
\def\FPfadd#1#2#3{\FP@callc\FP@add#1{#2}{#3}+\relax} % #1 := #2+#3
\def\FPdiv#1#2#3{\FP@callc\FP@div#1{#2}{#3}}        % #1 := #2/#3
\def\FPmul#1#2#3{\FP@callc\FP@mul#1{#2}{#3}}        % #1 := #2*#3
\def\FPfsub#1#2#3{\FP@callc\FP@add#1{#2}{-#3}-\relax}% #1 := #2-#3
%unary operations
\def\FPabs#1#2{\FP@calld\FP@abs#1{#2}}              % #1 := abs(#2)
\def\FPneg#1#2{\FP@calld\FP@neg#1{#2}}              % #1 := -#2
\def\FPsgn#1#2{\FP@calld\FP@sgn#1{#2}}              % #1 := sgn(#2)
%binary relations
\def\FPiflt#1#2{\FP@callb\FP@iflt{#1}{#2}+\relax}   % #1 < #2 ?
\def\FPifeq#1#2{\FP@callb\FP@ifeq{#1}{#2}}          % #1 = #2 ?
\def\FPifgt#1#2{\FP@callb\FP@iflt{#2}{#1}-\relax}   % #1 > #2 ?
%unary relations
\def\FPifneg#1{\FP@calla\FP@ifneg{#1}}              % #1 <  0 ?
\def\FPifpos#1{\FP@calla\FP@ifpos{#1}}              % #1 >= 0 ?
\def\FPifzero#1{\FP@calla\FP@ifzero{#1}}            % #1 =  0 ?
\def\FPifint#1{\FP@calla\FP@ifint{#1}}              % #1 is integer ?
%repeat last test
%\ifFPtest                                          % repeat last test

%%%private fp-area (don't use these macros)%%%

% To debug FP functions (enable intermediate messages on computations)
\newif\ifFPdebug
\FPdebugfalse
\def\FP@debug#1{\ifFPdebug\typeout{FP debug: #1}\fi}

%conditional printing of messages (only if \FPmessagestrue defined)
\newif\ifFPmessages
\FPmessagestrue
\def\FP@beginmessage#1{\ifFPmessages\message{( FP-#1}\fi}
\def\FP@endmessage#1{\ifFPmessages\message{)}\fi}
\def\FP@errmessage#1{\errmessage{FP error: #1!}}
\def\FP@warnmessage#1{\message{FP warning: #1!}}

%allocation of registers

\countdef\FP@actcounter=10 % register 0 for counter
\ifnum\FP@actcounter<60\relax%
  \FP@actcounter=60%
\fi

\newcount\FP@xs %sign of 1st value
\newcount\FP@xia%integer part of 1st value
\newcount\FP@xib%integer part of 1st value
\newcount\FP@xfa%fractional part of 1st value
\newcount\FP@xfb%fractional part of 1st value

\countdef\FP@ys=5 %sign of 2nd value
\countdef\FP@yia=6%integer part of 2nd value
\countdef\FP@yib=7%integer part of 2nd value
\countdef\FP@yfa=8%fractional part of 2nd value
\countdef\FP@yfb=9%fractional part of 2nd value

\countdef\FP@xk=10  %registers for splitting 1st value
\countdef\FP@xl=11
\countdef\FP@xm=12
\countdef\FP@xn=13
\countdef\FP@xo=14
\countdef\FP@xp=15
\countdef\FP@xq=16
\countdef\FP@xr=17
\countdef\FP@xz=18
\countdef\FP@xt=19
\countdef\FP@xu=20
\countdef\FP@xv=21

\countdef\FP@yk=22 %registers for splitting 2nd value
\countdef\FP@yl=23
\countdef\FP@ym=24
\countdef\FP@yn=25
\countdef\FP@yo=26
\countdef\FP@yp=27
\countdef\FP@yq=28
\countdef\FP@yr=29
\countdef\FP@yz=30
\countdef\FP@yt=31
\countdef\FP@yu=32
\countdef\FP@yv=33

\newcount\FP@rega   %auxiliary registers
\newcount\FP@regb
\countdef\FP@regc=36
\countdef\FP@regd=37
\countdef\FP@rege=38

\countdef\FP@rs=39 %result registers
\countdef\FP@ria=40
\countdef\FP@rib=41
\countdef\FP@rfa=42
\countdef\FP@rfb=43

\newcount\FP@regs    %local auxiliary registers
\countdef\FP@count=45
\countdef\FP@res=46
\countdef\FP@shift=47
\newcount\FP@times
\countdef\FP@prod=49

%set values
\def\FP@set[#1#2|#3#4]{%
  \ifx#3\@undefined%
    \expandafter\expandafter\expandafter\def\expandafter\expandafter\expandafter\FP@tmp\expandafter\expandafter\expandafter{\csname #3#4\endcsname}%
  \else\ifcat\noexpand#3\relax%
    \expandafter\def\expandafter\FP@tmp\expandafter{#3#4}%
  \else\ifcat#32\relax%
    \expandafter\def\expandafter\FP@tmp\expandafter{#3#4}%
  \else%
    \expandafter\expandafter\expandafter\def\expandafter\expandafter\expandafter\FP@tmp\expandafter\expandafter\expandafter{\csname #3#4\endcsname}%
  \fi\fi\fi%
  \ifx#1\@undefined%
    \let#1\FP@tmp%
  \else\ifcat\noexpand#1\relax%
    \let#1\FP@tmp%
  \else%
    \expandafter\let\csname #1#2\endcsname\FP@tmp%
  \fi\fi%
}

%print values
\def\FP@print[#1#2]{%
  \ifx#1\@undefined%
    \csname #1#2\endcsname%
  \else\ifcat\noexpand#1\relax%
    #1#2%
  \else\ifcat#12\relax%
    #1#2%
  \else%
    \csname #1#2\endcsname%
  \fi\fi\fi%
}

%auxiliary macros which may be used in all of the following macros
\newif\ifFP@test

\def\FP@ignorenext#1{}
\def\FP@first#1#2\relax{#1}
\def\FP@swallow#1\relax{}

\def\ifFP@zero#1{%
  \ifnum%
    \expandafter\ifnum\csname FP@#1ia\endcsname=0 0\else1\fi%
    \expandafter\ifnum\csname FP@#1ib\endcsname=0 0\else1\fi%
    \expandafter\ifnum\csname FP@#1fa\endcsname=0 0\else1\fi%
    \expandafter\ifnum\csname FP@#1fb\endcsname=0 0\else1\fi%
    =0\relax%
}

%read value

\def\FP@correctintcounter#1\relax{%
  {\edef\FP@tmp{#1}%
   \FP@count=0\relax%
   \loop%
     \edef\FP@tmpa{\expandafter\FP@first\FP@tmp\noexpand\relax}%
     \expandafter\ifx\FP@tmpa0\relax%
        \advance\FP@count1\relax%
        \edef\FP@tmp{\expandafter\FP@ignorenext\FP@tmp}%
     \repeat%
   \ifnum\FP@count>18\relax%
     \FP@errmessage{Overflow}%
   \fi%
   \expandafter\if!\FP@tmp!%
     \advance\FP@count-18\relax%
     \FP@count=-\FP@count%
     \loop%
       \ifnum\FP@count>0\relax%
          \FP@regc=\FP@rega%
          \divide\FP@rega10\relax\multiply\FP@rega10\relax%
          \advance\FP@regc-\FP@rega\multiply\FP@regc100000000\relax%
          \divide\FP@rega10\relax%
          \divide\FP@regb10\relax\advance\FP@regb\FP@regc%
          \advance\FP@count-1\relax%
       \repeat%
     \global\FP@rega=\FP@rega%
     \global\FP@regb=\FP@regb%
   \else%
     \FP@errmessage{Number too big}%
   \fi%
  }%
}
\def\FP@@setintcounter#1#2#3#4#5#6#7#8#9{%
  \FP@regb=#1#2#3#4#5#6#7#8#9\relax%
  \FP@correctintcounter%
}
\def\FP@setintcounter#1#2#3#4#5#6#7#8#9{%
  \FP@rega=#1#2#3#4#5#6#7#8#9\relax%
  \FP@@setintcounter%
}

\def\FP@@setfractcounter#1#2#3#4#5#6#7#8#9{%
  \FP@regb=#1#2#3#4#5#6#7#8#9\relax%
  \FP@swallow%
}
\def\FP@setfractcounter#1#2#3#4#5#6#7#8#9{%
  \FP@rega=#1#2#3#4#5#6#7#8#9\relax%
  \FP@@setfractcounter%
}

\def\FP@getsign#1\relax{%
  {\FP@regs=1\relax%
   \edef\FP@tmp{#1}%
   \loop%
     \edef\FP@tmpa{\expandafter\FP@first\FP@tmp\noexpand\relax}%
     \expandafter\ifx\FP@tmpa-\relax%
        \multiply\FP@regs-1\relax%
     \fi%
     \ifnum\expandafter\ifx\FP@tmpa-1\else0\fi\expandafter\ifx\FP@tmpa+1\else0\fi>0%
        \edef\FP@tmp{\expandafter\FP@ignorenext\FP@tmp}%
     \repeat%
   \global\let\FP@tmp\FP@tmp%
   \global\FP@regs=\FP@regs%
  }%
}

\def\FP@removeleadingzeros#1\relax{%
  {\edef\FP@tmp{#1}%
   \loop%
     \edef\FP@tmpa{\expandafter\FP@first\FP@tmp\noexpand\relax}%
     \expandafter\ifx\FP@tmpa0\relax%
       \edef\FP@tmp{\expandafter\FP@ignorenext\FP@tmp}%
     \repeat%
   \global\let\FP@tmp\FP@tmp%
  }%
}

\newif\ifFP@nonstop
\def\FP@strip#1{%
  {\edef\FP@tmp{#1}%
   \edef\FP@tmpb{}%
   \ifx\FP@tmp\@empty\else%
     \FP@nonstoptrue%
     \loop%
       \edef\FP@tmpa{\expandafter\FP@first\FP@tmp\noexpand\relax}%
       \expandafter\ifx\FP@tmpa-\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa+\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa0\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa1\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa2\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa3\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa4\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa5\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa6\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa7\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa8\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \expandafter\ifx\FP@tmpa9\relax\edef\FP@tmpb{\FP@tmpb\FP@tmpa}\else%
       \ifx\FP@tmpa\@empty\FP@nonstopfalse\else%
       \ifx\FP@tmpa\space\FP@nonstopfalse\else%
         \FP@errmessage{Illegal character \FP@tmpa\space found in float number}%
       \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi%
       \edef\FP@tmp{\expandafter\FP@ignorenext\FP@tmp}%
       \ifx\FP@tmp\@empty\FP@nonstopfalse\fi%
       \ifFP@nonstop%
       \repeat%
   \fi%
   \global\let\FP@tmp\FP@tmpb%
  }%
}

\def\FP@readvalue#1#2#3{%
  % #1    macro family to catch the value
  % #2.#3 value
  %
  % regular expression [+|-]*[d]_0^18.[d]*
  %
  \FP@strip{#2}%
  %sign
  \expandafter\FP@getsign\FP@tmp\relax%
  \csname FP@#1s\endcsname=\FP@regs%
  %
  %integer part
  \FP@removeleadingzeros\FP@tmp\relax%
  \expandafter\FP@setintcounter\FP@tmp000000000000000000\relax%
  \csname FP@#1ia\endcsname=\FP@rega%
  \csname FP@#1ib\endcsname=\FP@regb%
  %
  %fractional part
  \FP@strip{#3}%
  \expandafter\FP@setfractcounter\FP@tmp000000000000000000\relax%
  \csname FP@#1fa\endcsname=\FP@rega%
  \csname FP@#1fb\endcsname=\FP@regb%
  %
  %correct sign
  \ifnum\FP@rega=0\relax%
    \ifnum\FP@regb=0\relax%
      \expandafter\ifnum\csname FP@#1ib\endcsname=0\relax%
        \expandafter\ifnum\csname FP@#1ia\endcsname=0\relax%
          \csname FP@#1s\endcsname=1\relax%
        \fi%
      \fi%
    \fi%
  \fi%
}

%store value in macro

\def\FP@store#1#2{%
  % #1 macro
  % #2 macro family (value) to store
  %
  \ifFP@zero{#2}%
    \csname FP@#2s\endcsname=1\relax%
  \fi%
  \expandafter\ifnum\csname FP@#2s\endcsname<0\relax%
    \edef#1{-}%
  \else%
    \edef#1{}%
  \fi%
  \expandafter\ifnum\csname FP@#2ia\endcsname=0\relax%
     \expandafter\ifnum\csname FP@#2ib\endcsname=0\relax%
       \edef#1{#10}%
     \else%
       \edef#1{#1\expandafter\the\csname FP@#2ib\endcsname}%
     \fi%
  \else%
    \expandafter\advance\csname FP@#2ib\endcsname1000000000\relax%
    \edef#1{#1\expandafter\the\csname FP@#2ia\endcsname\expandafter\FP@ignorenext\the\csname FP@#2ib\endcsname}%
  \fi%
  \expandafter\advance\csname FP@#2fa\endcsname1000000000\relax%
  \expandafter\advance\csname FP@#2fb\endcsname1000000000\relax%
  \edef#1{#1\noexpand.\expandafter\FP@ignorenext\the\csname FP@#2fa\endcsname\expandafter\FP@ignorenext\the\csname FP@#2fb\endcsname}%
}

%macros to expand some arguments

\def\FP@calla#1#2{%
  % #1 macro to call
  % #2 value
  % expand the value and split them into the integer and the fractional part
  \edef\next{\noexpand#1#2..\noexpand\relax}%
  \next%
}

\def\FP@callb#1#2#3{%
  % #1 macro to call
  % #2 1st value
  % #3 2nd value
  % expand the values and split them into the integer and the fractional parts 
  \edef\next{\noexpand#1#2..\noexpand\relax#3..\noexpand\relax}%
  \next%
}

\def\FP@callc#1#2#3#4{%
  % #1 macro to call
  % #2 macro, which gets the result
  % #3 1st value
  % #4 2nd value
  % expand the values and split them into the integer and the fractional parts
  \edef\next{\noexpand#1\noexpand#2#3..\noexpand\relax#4..\noexpand\relax}%
  \next%
}

\def\FP@calld#1#2#3{%
  % #1 macro to call
  % #2 macro, which gets the result
  % #3 value
  \edef\next{\noexpand#1\noexpand#2#3..\noexpand\relax}%
  \next%
}

\def\FP@calle#1#2#3#4{%
  % #1 macro to call
  % #2 macro, which gets the first result
  % #3 macro, which gets the second result
  % #4 value
  \edef\next{\noexpand#1\noexpand#2\noexpand#3#4..\noexpand\relax}%
  \next%
}

%add two values

\def\FP@add#1#2.#3.#4\relax#5.#6.#7\relax#8\relax{%
  % #1 macro, which gets the result
  % #2 integer part of 1st value 
  % #3 fractional part of 1st value
  % #4 dummy to swallow everthing after the 2nd '.'
  % #5 integer part of 2nd value 
  % #6 fractional part of 2nd value
  % #7 dummy to swallow everthing after the 2nd '.'
  %
  {\ifx#8+\relax%
     \FP@beginmessage{ADD}%
   \else%
     \FP@beginmessage{SUB}%
   \fi%
   %
   \FP@readvalue{x}{#2}{#3}%
   \FP@readvalue{y}{#5}{#6}%
   %
   \ifnum\FP@xs=\FP@ys%
     \advance\FP@xfb\FP@yfb%
     \advance\FP@xfa\FP@yfa%
     \ifnum\FP@xfb<1000000000\relax\else%
       \advance\FP@xfb-1000000000\relax%
       \advance\FP@xfa1\relax%
     \fi%
     \advance\FP@xib\FP@yib%
     \ifnum\FP@xfa<1000000000\relax\else%
       \advance\FP@xfa-1000000000\relax%
       \advance\FP@xib1\relax%
     \fi%
     \advance\FP@xia\FP@yia%
     \ifnum\FP@xib<1000000000\relax\else%
       \advance\FP@xib-1000000000\relax%
       \advance\FP@xia1\relax%
     \fi%
     \ifnum\FP@xia<1000000000\relax\else%
       \FP@errmessage{Overflow}%
     \fi%
     \FP@store\FP@tmp{x}%
   \else%
     \advance\FP@xfb-\FP@yfb%
     \ifnum\FP@xfb<0\relax%
       \advance\FP@yfa1\relax%
       \advance\FP@xfb1000000000\relax%
     \fi%
     \advance\FP@xfa-\FP@yfa%
     \ifnum\FP@xfa<0\relax%
       \advance\FP@yib1\relax%
       \advance\FP@xfa1000000000\relax%
     \fi%
     \advance\FP@xib-\FP@yib%
     \ifnum\FP@xib<0\relax%
       \advance\FP@yia1\relax%
       \advance\FP@xib1000000000\relax%
     \fi%
     \advance\FP@xia-\FP@yia%
     \ifnum\FP@xia<0\relax%
       \FP@xs=-\FP@xs%
       \ifnum\FP@xfb=0\relax\else%
         \advance\FP@xfb-1000000000\relax\FP@xfb=-\FP@xfb%
         \advance\FP@xfa1\relax%
       \fi%
       \ifnum\FP@xfa=0\relax\else%
         \advance\FP@xfa-1000000000\relax\FP@xfa=-\FP@xfa%
         \advance\FP@xib1\relax%
       \fi%
       \ifnum\FP@xib=0\relax\else%
         \advance\FP@xib-1000000000\relax\FP@xib=-\FP@xib%
         \advance\FP@xia1\relax%
       \fi%
       \relax\FP@xia=-\FP@xia%
     \fi%
     \FP@store\FP@tmp{x}%
   \fi%
   %
   \global\let\FP@tmp\FP@tmp%
   %
   \FP@endmessage{}%
  }%
  \let#1\FP@tmp%
}

%multiply two values

\def\FP@firstnine#1#2#3#4#5#6#7#8#9{%
  \FP@res=#1#2#3#4#5#6#7#8#9\relax%
}
\def\FP@@ninesplit#1\relax#2\end#3{%
  #1%
  \edef#3{#2}%
}
\def\FP@ninesplit#1{%
  \edef#1{\expandafter\FP@firstnine\FP@rd}%
  \expandafter\FP@@ninesplit#1\end#1\relax%
}

\def\FP@split#1#2#3#4{%
  % #1 highest three digits
  % #2 medium three digits
  % #3 least three digits
  % #4 counter
  \FP@regc=#4%
  \divide\FP@regc1000000\relax%
  #1=\FP@regc%
  \multiply\FP@regc-1000000\relax\advance\FP@regc#4%
  #3=\FP@regc%
  \divide\FP@regc1000\relax%
  #2=\FP@regc%
  \multiply\FP@regc-1000\relax\advance\FP@regc#3%
  #3=\FP@regc%
}

\def\FP@@mul#1#2#3{%
  \FP@regc=\csname FP@x#1\endcsname%
  \multiply\FP@regc\csname FP@y#2\endcsname%
  \advance\FP@prod\FP@regc%
  %
  \ifx#3\relax%
    \let\next=\relax% 
  \else%
    \let\next=\FP@@mul%
  \fi%
  \next#3%
}

\def\FP@saveshift{%
  % save rightmost three digits 
  \FP@regc=\FP@prod%
  \divide\FP@prod1000\relax%
  \multiply\FP@prod1000\relax%
  \advance\FP@regc-\FP@prod%
  \advance\FP@regc1000\relax%
  \edef\FP@rd{\expandafter\FP@ignorenext\the\FP@regc\FP@rd}%
  %
  \divide\FP@prod1000\relax%
}

\def\FP@mul#1#2.#3.#4\relax#5.#6.#7\relax{%
  % #1 macro, which gets the result
  % #2 integer part of 1st value 
  % #3 fractional part of 1st value
  % #4 dummy to swallow everthing after the 2nd '.'
  % #5 integer part of 2nd value 
  % #6 fractional part of 2nd value
  % #7 dummy to swallow everthing after the 2nd '.'
  %
  % split value in various parts
  % x y = 123 456 789 123 456 789 . 123 456 789 123 456 789
  % ->    xk  xl  xm  xn  xo  xp    xq  xr  xs  xt  xu  xv
  % ->    yk  yl  ym  yn  yo  yp    yq  yr  ys  yt  yu  yv
  % multiply these parts and save the result wrt the necessary shifts
  %
  {\FP@beginmessage{MUL}%
   %
   \FP@readvalue{x}{#2}{#3}%
   \FP@readvalue{y}{#5}{#6}%
   %
   %sign
   \multiply\FP@xs\FP@ys%
   \FP@rs=\FP@xs%
   %
   % split parts
   \FP@split\FP@xk\FP@xl\FP@xm\FP@xia\FP@split\FP@xn\FP@xo\FP@xp\FP@xib%
   \FP@split\FP@xq\FP@xr\FP@xz\FP@xfa\FP@split\FP@xt\FP@xu\FP@xv\FP@xfb%
   \FP@split\FP@yk\FP@yl\FP@ym\FP@yia\FP@split\FP@yn\FP@yo\FP@yp\FP@yib%
   \FP@split\FP@yq\FP@yr\FP@yz\FP@yfa\FP@split\FP@yt\FP@yu\FP@yv\FP@yfb%
   %
   \FP@prod=0\relax%
   \edef\FP@rd{}%
   %
   %compute result
   \FP@@mul vv                                  \relax\FP@saveshift%
   \FP@@mul vu uv                               \relax\FP@saveshift%
   \FP@@mul uu vt tv                            \relax\FP@saveshift%
   \FP@@mul ut tu vz zv                         \relax\FP@saveshift%
   \FP@@mul tt zu uz rv vr                      \relax\FP@saveshift%
   \FP@@mul zt tz ur ru vq qv                   \relax\FP@saveshift%
   \FP@@mul zz rt tr uq qu vp pv                \relax\FP@saveshift%
   \FP@@mul zr rz tq qt up pu vo ov             \relax\FP@saveshift%
   \FP@@mul rr qz zq tp pt uo ou vn nv          \relax\FP@saveshift%
   \FP@@mul rq qr zp pz to ot un nu vm mv       \relax\FP@saveshift%
   \FP@@mul qq rp pr zo oz tn nt um mu vl lv    \relax\FP@saveshift%
   \FP@@mul qp pq ro or zn nz tm mt ul lu kv vk \relax\FP@saveshift%
   \FP@@mul pp oq qo rn nr zm mz tl lt ku uk    \relax\FP@saveshift%
   \FP@@mul op po nq qn rm mr zl lz tk kt       \relax\FP@saveshift%
   \FP@@mul oo pn np mq qm rl lr kz zk          \relax\FP@saveshift%
   \FP@@mul no on mp pm lq ql kr rk             \relax\FP@saveshift%
   \FP@@mul nn mo om pl lp qk kq                \relax\FP@saveshift%
   \FP@@mul mn nm lo ok pk kp                   \relax\FP@saveshift%
   \FP@@mul mm ln nl ko ok                      \relax\FP@saveshift%
   \FP@@mul lm ml kn nk                         \relax\FP@saveshift%
   \FP@@mul ll km mk                            \relax\FP@saveshift%
   \FP@@mul kl lk                               \relax\FP@saveshift%
   \FP@@mul kk                                  \relax\FP@saveshift\FP@saveshift%
   \FP@ninesplit\FP@rd%
   \ifnum\FP@res=0\relax%
     \FP@ninesplit\FP@rd%
     \ifnum\FP@res=0\relax%
       \FP@ninesplit\FP@rd\FP@ria=\FP@res%
       \FP@ninesplit\FP@rd\FP@rib=\FP@res%
       \FP@ninesplit\FP@rd\FP@rfa=\FP@res%
       \FP@ninesplit\FP@rd\FP@rfb=\FP@res%
       \FP@store\FP@tmp{r}%
     \else%
       \FP@errmessage{Overflow}%
     \fi%
   \else%
     \FP@errmessage{Overflow}%
   \fi%
   %
   \global\let\FP@tmp\FP@tmp%
   %
   \FP@endmessage{}%
  }%
  %
  \let#1\FP@tmp%
}

%divide one value by another one

\def\FP@divten#1{%
  \expandafter\FP@regc\csname FP@#1ia\endcsname%
  \expandafter\divide\csname FP@#1ia\endcsname10\relax%
  \expandafter\FP@regb\csname FP@#1ia\endcsname%
  \multiply\FP@regb10\relax%
  \advance\FP@regc-\FP@regb%
  \multiply\FP@regc100000000\relax%
  %
  \expandafter\FP@rega\csname FP@#1ib\endcsname%
  \expandafter\divide\csname FP@#1ib\endcsname10\relax%
  \expandafter\FP@regb\csname FP@#1ib\endcsname%
  \multiply\FP@regb10\relax%
  \advance\FP@rega-\FP@regb%
  \multiply\FP@rega100000000\relax%
  \expandafter\advance\csname FP@#1ib\endcsname\FP@regc%
  %
  \expandafter\FP@regc\csname FP@#1fa\endcsname%
  \expandafter\divide\csname FP@#1fa\endcsname10\relax%
  \expandafter\FP@regb\csname FP@#1fa\endcsname%
  \multiply\FP@regb10\relax%
  \advance\FP@regc-\FP@regb%
  \multiply\FP@regc100000000\relax%
  \expandafter\advance\csname FP@#1fa\endcsname\FP@rega%
  %
  \expandafter\divide\csname FP@#1fb\endcsname10\relax%
  \expandafter\advance\csname FP@#1fb\endcsname\FP@regc%
}

\def\FP@multen#1{%
  \expandafter\multiply\csname FP@#1ia\endcsname10\relax%
  \expandafter\ifnum\csname FP@#1ib\endcsname<100000000\relax%
  \else%
    \expandafter\FP@regc\csname FP@#1ib\endcsname%
    \divide\FP@regc100000000%
    \expandafter\advance\csname FP@#1ia\endcsname\FP@regc%
    \multiply\FP@regc100000000%
    \expandafter\advance\csname FP@#1ib\endcsname-\FP@regc%
  \fi%
  \expandafter\multiply\csname FP@#1ib\endcsname10\relax%
  \expandafter\ifnum\csname FP@#1fa\endcsname<100000000\relax%
  \else%
    \expandafter\FP@regc\csname FP@#1fa\endcsname%
    \divide\FP@regc100000000%
    \expandafter\advance\csname FP@#1ib\endcsname\FP@regc%
    \multiply\FP@regc100000000%
    \expandafter\advance\csname FP@#1fa\endcsname-\FP@regc%
  \fi%
  \expandafter\multiply\csname FP@#1fa\endcsname10\relax%
  \expandafter\ifnum\csname FP@#1fb\endcsname<100000000\relax%
  \else%
    \expandafter\FP@regc\csname FP@#1fb\endcsname%
    \divide\FP@regc100000000%
    \expandafter\advance\csname FP@#1fa\endcsname\FP@regc%
    \multiply\FP@regc100000000%
    \expandafter\advance\csname FP@#1fb\endcsname-\FP@regc%
  \fi%
  \expandafter\multiply\csname FP@#1fb\endcsname10\relax%
}

\def\FP@counttimes{%
  {\global\FP@times=0\relax%
   \loop%
     \ifnum%
        \ifnum\FP@xia>\FP@yia1%
        \else\ifnum\FP@xia<\FP@yia0%
        \else%
          \ifnum\FP@xib>\FP@yib1%
          \else\ifnum\FP@xib<\FP@yib0%
          \else%
            \ifnum\FP@xfa>\FP@yfa1%
            \else\ifnum\FP@xfa<\FP@yfa0%
            \else%
              \ifnum\FP@xfb>\FP@yfb1%
              \else\ifnum\FP@xfb<\FP@yfb0%
              \else%
                 1%
              \fi\fi%
            \fi\fi%
          \fi\fi%
        \fi\fi%
        =1\relax%
       \global\advance\FP@times1\relax%
       \global\advance\FP@xfb-\FP@yfb%
       \ifnum\FP@xfb<0\relax%
         \global\advance\FP@xfb1000000000\relax%
         \global\advance\FP@xfa-1\relax%
       \fi%
       \global\advance\FP@xfa-\FP@yfa%
       \ifnum\FP@xfa<0\relax%
         \global\advance\FP@xfa1000000000\relax%
         \global\advance\FP@xib-1\relax%
       \fi%
       \global\advance\FP@xib-\FP@yib%
       \ifnum\FP@xib<0\relax%
         \global\advance\FP@xib1000000000\relax%
         \global\advance\FP@xia-1\relax%
       \fi%
       \global\advance\FP@xia-\FP@yia%
     \repeat%
  }%
}

\def\FP@div#1#2.#3.#4\relax#5.#6.#7\relax{%
  % #1 macro, which gets the result
  % #2 integer part of 1st value 
  % #3 fractional part of 1st value
  % #4 dummy to swallow everthing after the 2nd '.'
  % #5 integer part of 2nd value 
  % #6 fractional part of 2nd value
  % #7 dummy to swallow everthing after the 2nd '.'
  %
  % algorithmic idea (for x>0, y>0)
  %   - %determine \FP@shift  such that y*10^\FP@shift <100000000<=y*10^(\FP@shift+1)
  %   - %determine \FP@shift' such that x*10^\FP@shift'<100000000<=x*10^(\FP@shift+1)
  %   - x=x*\FP@shift'
  %   - y=y*\FP@shift
  %   - \FP@shift=\FP@shift-\FP@shift'
  %   - res=0
  %   - while y>0 %fixed-point representation!
  %   -   \FP@times=0
  %   -   while x>y
  %   -     \FP@times=\FP@times+1
  %   -     x=x-y
  %   -   end
  %   -   y=y/10
  %   -   res=10*res+\FP@times/1000000000
  %   - end
  %   - %shift the result according to \FP@shift
  %
  {\FP@beginmessage{DIV}%
   %
   \FP@readvalue{x}{#2}{#3}%
   \FP@readvalue{y}{#5}{#6}%
   %
   %sign
   \multiply\FP@xs\FP@ys%
   \FP@rs=\FP@xs%
   %
   %compute division
   \ifFP@zero{y}%
     \FP@errmessage{Division by zero}%
   \else%
     \ifFP@zero{x}\def\next##1{\edef\FP@tmp{0}}\else\def\next##1{##1}\fi%
     \next%
       {\FP@shift=0\relax%
        \loop%
          \ifnum\FP@yia<100000000\relax%
             \FP@multen{y}%
             \advance\FP@shift1\relax%
           \repeat%
        \loop%
          \ifnum\FP@xia<100000000\relax%
             \FP@multen{x}%
             \advance\FP@shift-1\relax%
          \repeat%
        \FP@ria=0\FP@rib=0\FP@rfa=0\FP@rfb=0\relax%
        \loop%
          \ifFP@zero{y}\else%
             \FP@counttimes%divides x by \FP@times*y
             \FP@divten{y}%
             \FP@multen{r}%
             \advance\FP@rfb\FP@times%
             \ifnum\FP@rfb<1000000000\relax\else%
               \advance\FP@rfa1\advance\FP@rfb-1000000000\relax%
               \ifnum\FP@rfa<1000000000\relax\else%
                 \advance\FP@rib1\advance\FP@rfa-1000000000\relax%
                 \ifnum\FP@rib<1000000000\relax\else%
                   \advance\FP@ria1\advance\FP@rib-1000000000\relax%
                 \fi%
               \fi%
             \fi%
          \repeat%
        \loop%
          \ifnum\FP@shift>17%
            \advance\FP@shift-1\relax%
            \ifnum\FP@ria<100000000\else\FP@ria=-1\fi%
            \ifnum\FP@ria<0\FP@ria=-1\fi%
            \FP@multen{r}%
          \repeat%
        \ifnum\FP@ria<1000000000\else\FP@ria=-1\fi%
        \loop%
          \ifnum\FP@shift<17%
            \advance\FP@shift1\relax%
            \FP@divten{r}%
          \repeat%
        \ifnum\FP@ria<0\relax%
          \FP@errmessage{Overflow}%
        \else%
          \FP@store\FP@tmp{r}%
        \fi%
       }%
    \fi%
   %
   \global\let\FP@tmp=\FP@tmp%
   %
   \FP@endmessage{}%
  }%
  \let#1\FP@tmp%
}

%absolute value

\def\FP@abs#1#2.#3.#4\relax{%
  % #1 macro, which gets the result
  % #2 integer part of value
  % #3 fractional part of value
  % #4 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{ABS}%
   %
   \FP@readvalue{x}{#2}{#3}%
   \FP@xs=1\relax%
   \FP@store\FP@tmp{x}%
   %
   \global\let\FP@tmp\FP@tmp%
   %
   \FP@endmessage{}%
  }%
  \let#1\FP@tmp%
}

%negate value

\def\FP@neg#1#2.#3.#4\relax{%
  % #1 macro, which gets the result
  % #2 integer part of value
  % #3 fractional part of value
  % #4 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{NEG}%
   %
   \FP@readvalue{x}{#2}{#3}%
   \multiply\FP@xs-1\relax%
   \FP@store\FP@tmp{x}%
   %
   \global\let\FP@tmp\FP@tmp%
   %
   \FP@endmessage{}%
  }%
  \let#1\FP@tmp%
}

%sign of value

\def\FP@sgn#1#2.#3.#4\relax{%
  % #1 macro, which gets the result
  % #2 integer part of value
  % #3 fractional part of value
  % #4 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{SGN}%
   %
   \FP@readvalue{x}{#2}{#3}%
   %
   \ifFP@zero{x}%
     \edef\FP@tmp{0}%
   \else%
     \edef\FP@tmp{\the\FP@xs}%
   \fi%
   %
   \global\let\FP@tmp\FP@tmp%
   %
   \FP@endmessage{}%
  }%
  \let#1\FP@tmp%
}

%test if 1st value is less than 2nd value

\def\FP@iflt#1.#2.#3\relax#4.#5.#6\relax#7\relax{%
  % #1 integer part of 1st value 
  % #2 fractional part of 1st value
  % #3 dummy to swallow everthing after the 2nd '.'
  % #4 integer part of 2nd value 
  % #5 fractional part of 2nd value
  % #6 dummy to swallow everthing after the 2nd '.'
  %
  {\ifx#7+\relax%
     \FP@beginmessage{LT?}%
   \else%
     \FP@beginmessage{GT?}%
   \fi%
   %
   \FP@readvalue{x}{#1}{#2}%
   \FP@readvalue{y}{#4}{#5}%
   %
   \ifnum\FP@xs<\FP@ys%
     \FP@testtrue%
   \else\ifnum\FP@xs>\FP@ys%
     \FP@testfalse%
   \else%
     \ifnum\FP@xs>0\relax%
        \ifnum\FP@xia<\FP@yia%
          \FP@testtrue%
        \else\ifnum\FP@xia>\FP@yia%
          \FP@testfalse%
        \else%
          \ifnum\FP@xib<\FP@yib%
            \FP@testtrue%
          \else\ifnum\FP@xib>\FP@yib%
            \FP@testfalse%
          \else%
            \ifnum\FP@xfa<\FP@yfa%
              \FP@testtrue%
            \else\ifnum\FP@xfa>\FP@yfa%
              \FP@testfalse%
            \else%
              \ifnum\FP@xfb<\FP@yfb%
                \FP@testtrue%
              \else%
                \FP@testfalse%
              \fi%
            \fi\fi%
          \fi\fi%
        \fi\fi%
     \else%
        \ifnum\FP@xia>\FP@yia%
          \FP@testtrue%
        \else\ifnum\FP@xia<\FP@yia%
          \FP@testfalse%
        \else%
          \ifnum\FP@xib>\FP@yib%
            \FP@testtrue%
          \else\ifnum\FP@xib<\FP@yib%
            \FP@testfalse%
          \else%
            \ifnum\FP@xfa>\FP@yfa%
              \FP@testtrue%
            \else\ifnum\FP@xfa<\FP@yfa%
              \FP@testfalse%
            \else%
              \ifnum\FP@xfb>\FP@yfb%
                \FP@testtrue%
              \else%
                \FP@testfalse%
              \fi%
            \fi\fi%
          \fi\fi%
        \fi\fi%
     \fi%
   \fi\fi%
   %
   \global\let\ifFP@test\ifFP@test%
   %
   \FP@endmessage{}%
  }%
  \let\ifFPtest\ifFP@test%
  %
  \ifFPtest%
}

%test if two values are equal

\def\FP@ifeq#1.#2.#3\relax#4.#5.#6\relax{%
  % #1 integer part of 1st value 
  % #2 fractional part of 1st value
  % #3 dummy to swallow everthing after the 2nd '.'
  % #4 integer part of 2nd value 
  % #5 fractional part of 2nd value
  % #6 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{EQ?}%
   %
   \FP@readvalue{x}{#1}{#2}%
   \FP@readvalue{y}{#4}{#5}%
   %
   \ifnum\FP@xs=\FP@ys%
     \ifnum\FP@xia=\FP@yia%
       \ifnum\FP@xib=\FP@yib%
         \ifnum\FP@xfa=\FP@yfa%
           \ifnum\FP@xfb=\FP@yfb%
             \FP@testtrue%
           \else%
             \FP@testfalse%
           \fi%
         \else%
           \FP@testfalse%
         \fi%
       \else%
         \FP@testfalse%
       \fi%
     \else%
       \FP@testfalse%
     \fi%
   \else%
     \FP@testfalse%
   \fi%
   %
   \global\let\ifFP@test\ifFP@test%
   %
   \FP@endmessage{}%
  }%
  \let\ifFPtest\ifFP@test%
  %
  \ifFPtest%
}

%test if value is negative

\def\FP@ifneg#1.#2.#3\relax{%
  % #1 integer part of value
  % #2 fractional part of value
  % #3 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{NEG?}%
   %
   \FP@readvalue{x}{#1}{#2}%
   %
   \ifnum\FP@xs<0\relax%
     \FP@testtrue%
   \else%
     \FP@testfalse%
   \fi%
   %
   \global\let\ifFP@test\ifFP@test%
   %
   \FP@endmessage{}%
  }%
  \let\ifFPtest\ifFP@test%
  %
  \ifFPtest%
}

%test if value is positive

\def\FP@ifpos#1.#2.#3\relax{%
  % #1 integer part of value
  % #2 fractional part of value
  % #3 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{POS?}%
   %
   \FP@readvalue{x}{#1}{#2}%
   %
   \ifnum\FP@xs<0\relax%
     \FP@testfalse%
   \else%
     \FP@testtrue%
   \fi%
   %
   \global\let\ifFP@test\ifFP@test%
   %
   \FP@endmessage{}%
  }%
  \let\ifFPtest\ifFP@test%
  %
  \ifFPtest%
}

%test if value is equal to zero

\def\FP@ifzero#1.#2.#3\relax{%
  % #1 integer part of value
  % #2 fractional part of value
  % #3 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{ZERO?}%
   %
   \FP@readvalue{x}{#1}{#2}%
   %
   \ifFP@zero{x}%
     \FP@testtrue%
   \else%
     \FP@testfalse%
   \fi%
   %
   \global\let\ifFP@test\ifFP@test%
   %
   \FP@endmessage{}%
  }%
  \let\ifFPtest\ifFP@test%
  %
  \ifFPtest%
}

%test if value is an integer

\def\FP@ifint#1.#2.#3\relax{%
  % #1 integer part of value
  % #2 fractional part of value
  % #3 dummy to swallow everthing after the 2nd '.'
  %
  {\FP@beginmessage{INT?}%
   %
   \FP@readvalue{x}{#1}{#2}%
   %
   \ifnum\FP@xfa=0\relax%
     \ifnum\FP@xfb=0\relax%
       \FP@testtrue%
     \else%
       \FP@testfalse%
     \fi%
   \else%
     \FP@testfalse%
   \fi%
   %
   \global\let\ifFP@test\ifFP@test%
   %
   \FP@endmessage{}%
  }%
  \let\ifFPtest\ifFP@test%
  %
  \ifFPtest%
}
