% -*- mode: latex; auto-revert-interval: 0.5 -*-

\begin{tikzpicture}[->,>=stealth',shorten >=1pt,auto, node distance=3em,
                   very thin,font={\scriptsize\bf}]

  \pgfdeclarelayer{background}
  \pgfdeclarelayer{foreground}
  \pgfsetlayers{background,main,foreground}

  \tikzstyle{basic-block} = [draw=black!50, fill=white, rectangle, 
      minimum width=6em, minimum height=1.1em]
  \ifthenelse{\boolean{preview}}
    {\tikzstyle{block} = [basic-block]}
    {\tikzstyle{block} = [basic-block, drop shadow]}

  \tikzstyle{enter} = [block, ellipse, fill=red!20]
  \tikzstyle{guard} = [block, fill=yellow!20]
  \tikzstyle{newguard} = [block, fill=green!20]
  \tikzstyle{lbl} = [font={\scriptsize\it}, minimum width=0em]

  \clip (-1.3, 0.6) rectangle (12.8,-5.9); 

  % entry bridge
  \node[enter, name=entry0, fill=blue!20] {entry} ;
  \node[guard, name=entry1, below of=entry0] {...};
  \path (entry0.south) edge (entry1.north) ;

  % main loop
  \node[enter, name=loop0, below right=2em and 5em of entry0] {loop 1} ;
  \node[guard, name=loop1, below of=loop0] {...} ;
  \node[guard, name=loop2, below of=loop1] {...} ;  
  \node[guard, name=loop3, below of=loop2] {...};
  \path (loop0.south) edge (loop1.north) ;
  \path (loop1.south) edge (loop2.north) ;
  \path (loop2.south) edge (loop3.north) ;
  \path (loop3.south) 
            edge[distance=9em, out=230, in=130]
        (loop0.north) ;

  % other loop
  \node[enter, name=other0, below right=1em and 13em of loop0] {loop 2} ;
  \node[guard, name=other1, below of=other0] {...} ;
  \path (other0.south) edge (other1.north) ;
  \path (other1.south) 
            edge[distance=9em, out=310, in=50]
        (other0.north) ;


  % entry bridge --> main loop
  \path (entry1.south)
            edge[in distance=12em, out distance=9em, out=300, in=110]
        (loop0.north);


  % inner bridge
  \node[newguard, name=inner0, right=1.5em of loop2] {inner};
  \path (loop1.south east) edge (inner0.north) ;
  \path (inner0.south) 
            edge[out distance=12em, in distance=10em, out=340, in=70] 
        (loop0.north) ;

  % exit bridge
  \node[newguard, name=exit0, right=1.5em of loop3, fill=black!10] {exit};
  \path (loop2.south east) edge (exit0.north) ;
  \path (exit0.south) 
            edge[out distance=10em, in distance=10em, out=320, in=130] 
        (other0.north) ;
    
    
\end{tikzpicture}