\begin{figure}[H]
  \begin{center}
  \unitlength=4pt
  \begin{picture}(15, 28)(0,-10)
  \gasset{Nw=5,Nh=5,Nmr=2.5,curvedepth=3}
  \thinlines
  \node(A0)(7.5,0){$0$}
  \node[Nmarks=i,iangle=90](A1)(0,13){$1$}
  \node[Nmarks=if,iangle=90,fangle=90](A2)(15,13){$2$}
  \drawloop[loopangle=180](A1){$a$}
  \drawloop[loopangle=0](A2){$b$}
  \drawedge(A1,A2){$a$}
  \drawedge(A2,A1){$b$}
  \drawedge(A2,A0){$a$}
  \gasset{curvedepth=-3}
  \drawedge[ELside=r](A1,A0){$b$}
  \drawloop[loopangle=270](A0){$a, b$}
  \end{picture}
  \end{center}
  \caption{La complétion de l'automate.}
\end{figure}