let () =
  let svg = Svg.new_svg_document ~width:480 ~height:180 () in

  Svg.add_rect svg
    ~x:0 ~y:0
    ~width:480
    ~height:180
    ~fill:"#fff"
    ~stroke:"#000"
    ~stroke_width:2.0
   ()
   ;

  Svg.Float.add_line svg
    ~x1:45.5   ~y1:45.5
    ~x2:410.5  ~y2:45.5
    ~stroke:"#000"
    ~stroke_width:1.0
   ()
   ;

  Svg.Float.add_line svg
    ~x1:45.5   ~y1:135.5
    ~x2:370.5  ~y2:135.5
    ~stroke:"#000"
    ~stroke_width:1.0
   ()
   ;

  Svg.Float.add_line svg
    ~x1:50.5   ~y1:40.5
    ~x2:50.5   ~y2:140.5
    ~stroke:"#000"
    ~stroke_width:1.0
   ()
   ;

  Svg.finish_svg svg;
  Svg.print_svg_document svg;
;;