usepackage{tikz}
begin{tikzpicture}[>=stealth',shorten >=1pt,auto,node distance=2cm]
  node[initial,state] (q0)      {$q0$};
  node[state]         (q1) [right of=q0]  {$q_1$};
  node[state]         (q2) [right of=q1] {$q_2$};
  node[state, accepting] (q3) [below of=q1] {$q_3$};


  path[->] (q0)  edge [loop above] node {a} (q0)
             edge              node {a} (q1)
        (q1) edge [loop above] node {a;$bot/Abot$, $a;A/AA$} (q1)
             edge [bend left]  node {a} (q0)
             edge              node {b} (q2)
        (q2) edge [loop above] node {b} (q2)
             edge [bend left]  node {b} (q1);
end{tikzpicture}