\begin{figure}[H]
  \begin{center}
    \unitlength=4pt
    \begin{picture}(80, 32)(-10,-30)
    \gasset{Nw=5,Nh=5,Nmr=2.5,curvedepth=0}
    \thinlines
    \put(-10,-13){$\cal A$:}
    \node[Nmarks=if,iangle=180,fangle=90](A1)(0,0){}
    \node(Aa)(10,-10){}
    \node(Ab)(25,-10){}
    \node[Nmarks=f,fangle=0](Ac)(17.5,-22){}
    \drawloop[loopangle=270](Ac){$a_3$}
    \drawedge(A1,Aa){$a_1$}
    \gasset{curvedepth=3.5}
    \drawedge(Aa,Ab){$a_2$}
    \drawedge(Ab,Aa){$a_1$}
    \drawedge(Ac,Aa){$a_1$}
    \drawedge(Ab,Ac){$a_3$}
    \gasset{curvedepth=-8}
    \drawedge[ELside=r](A1,Ac){$a_3$}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    \put(30,-13){$\rightarrow\ {\cal A}':$}
    \node[Nmarks=if,iangle=180,fangle=90](A1)(45,0){}
    \node(Aa)(55,-10){}
    \node(Ab)(70,-10){}
    \node[Nmarks=f,fangle=0](Ac)(62.5,-22){}
    \drawloop[loopangle=270](Ac){$a$}
    \drawedge[curvedepth=0,ELside=l](A1,Aa){$a$}
    \gasset{curvedepth=3.5}
    \drawedge(Aa,Ab){$b$}
    \drawedge(Ab,Aa){$a$}
    \drawedge(Ac,Aa){$a$}
    \drawedge(Ab,Ac){$a$}
    \gasset{curvedepth=-8}
    \drawedge[ELside=r](A1,Ac){$a$}
    \end{picture}
  \end{center}
  \caption{Un automate pour $[(ab)^*a]^*$.}
\end{figure}