'begin'
   'mode''point'='struct'('real'x,y);
   'mode''polygon'='struct'('int'colour,[3]'point'vertices);
   'proc'draw=('polygon'p)'void':
      'begin' print(("polygon:-->color=",colour'of'p,newline,"vertices:"));
          []'point'pp=vertices'of'p;
          'for'i'to''upb'pp'do'
                  'point'o=pp[i];
                  print(("(",x'of'o,y'of'o,")"))
          'od';
          print(newline)
       'end';
    'polygon'pink triangle=(0,((0,0),(.5,1),(1,0))),
             black square =(1,((0,0),(0,1),(1,1),(1,0)));
    draw(pink triangle); draw(black square);
    'polygon'shape; shape:=pink triangle;
    draw(shape);
    vertices'of'shape:=(vertices'of'black square)[:3];
    draw(shape)
'end'