\documentclass{article}
\usepackage[usenames]{color}
\usepackage{gastex}

\begin{document}

% and more ...

\begin{center}
\begin{picture}(120,52)(-35,-37)
\put(-35,-37){\framebox(120,52){}}
  \node[Nw=16,linecolor=Yellow,fillcolor=Yellow](A)(-20,0){initial}
  \imark[iangle=200,linecolor=Peach](A)
  \node[Nmr=0,Nw=14,fillgray=0.85,
        dash={1}0](B)( 20,0){\textcolor{RedViolet}{final}}
  \fmark[flength=10,fangle=-30,dash={3 1 1 1}0](B)
  \node[Nadjust=wh,Nadjustdist=2,Nmr=3,Nmarks=r,linecolor=Green](C)(60,-20){$\left(
    \begin{array}{ccc}
         2 &  1 & 0  \\
        -1 &  0 & 1  \\
         0 & -1 & 2
    \end{array}
    \right)$}
  \rmark[linecolor=Green,rdist=1.4](C)
 
  \drawedge[curvedepth=5,linecolor=Red](A,B){\textcolor{Cyan}{curved}}
  \drawedge[ELside=r,ELpos=35](A,B){straight}
  \drawedge[curvedepth=-25,ELside=r,dash={1.5}0](A,B){far}
  \drawloop[ELpos=75, loopangle=150, dash={0.2 0.5}0](A){loopCW}
  \drawloop[loopCW=n,ELside=r,loopangle=30,dash={3 1.5}{1.5}](B){loopCCW}
  \drawqbpedge[ELside=r,ELdist=0,dash={4 1 1 1}0](B,-90,C,180){qbpedge}
  \drawloop[ELpos=70,loopangle=0](C){$b / 01$}
  \drawloop[loopCW=n,ELpos=75,ELside=r,loopangle=-90,sxo=6](C){$a / 01$}
  \drawloop[ELpos=75,loopangle=-90,sxo=-6](C){$b / 10 $}
  \drawloop[loopangle=50](C){$b / 01$}
  \drawloop[ELpos=75,loopangle=148](C){$b / 01$}
\end{picture}
\end{center}

\end{document}