\documentclass{article}
\usepackage{gastex}

\begin{document}

% Edges

\begin{center}
\begin{picture}(120,60)(-32,-14)
\put(-32,-14){\framebox(120,60){}}
  \node(A)(10,0){}\node(B)(40,0){}
  \drawedge(A,B){straight}
  \drawedge[curvedepth=8](A,B){positive curve depth}
  \drawedge[curvedepth=-8,ELside=r](A,B){negative curve depth}
  \drawloop[loopangle=180](A){180}
  \drawloop[loopangle=0](B){0}

  \node(A)(-15,30){}\node(B)(15,30){}
  \drawqbedge(A,-15,50,B){qbedge}
  \drawbcedge(A,-20,10,B,20,10){bcedge}
  \drawloop[loopangle=210](A){210}
  \drawloop[loopangle=90,loopCW=n,ELside=r](B){90}

  \node(A)(40,30){}\node(B)(70,30){}
  \drawbpedge[ELpos=30,ELdist=0](A,45,20,B,225,20){bpedge}
  \drawbpedge[ELpos=30,ELside=r](A,210,30,B,-30,30){30}
  \drawbpedge[ELpos=70,ELside=r](A,210,30,B,-30,30){70}
  \drawloop[loopdiam=5,loopangle=120,ELpos=60](A){larger}
  \drawloop[loopdiam=10,loopangle=30,ELpos=30](B){smaller}
\end{picture}
\end{center}

\end{document}