  Single


  First

red        green
     blue       
red        green

  Second

     blue       
red        green
     blue       

  Nested

red        green       blue              blue       
     blue         red        green  red        green
red        green       blue              blue       
                                                    
     blue         red        green       blue       
red        green       blue         red        green
     blue         red        green       blue       
                                                    
red        green       blue              blue       
     blue         red        green  red        green
red        green       blue              blue       
                                                    
