\begin{figure}[H]
  \begin{center}
    \unitlength=4pt
    \begin{picture}(15, 25)(0,-8)
    \gasset{Nw=5,Nh=5,Nmr=2.5,curvedepth=3}
    \thinlines
    \node(A0)(7.5,0){$0$}
    \node[Nmarks=if,iangle=180,fangle=90](A1)(0,13){$1$}
    \node(A2)(15,13){$2$}
    \drawloop[loopangle=270](A0){$a,b$}
    \gasset{curvedepth=-3}
    \drawedge[ELside=r](A1,A0){$b$}
    \gasset{curvedepth=3}
    \drawedge(A1,A2){$a$}
    \drawedge(A2,A1){$b$}
    \drawedge(A2,A0){$a$}
    \end{picture}
  \end{center}
  \caption{Un automate déterministe complet.}
\end{figure}