applications.collages.collageAlgebra:
{
  ntColour = const(.8),
  xmax = const(26.556),
  ymax = const(99.585),
  
  stem = { filledPolygon((-.3,0), (-.255,16.015), (.255,16.015), (.3,0)) },
  sample-outline = { closedCurve((0,0),
                                 (23,28) left (-7,-21) right (3,9),
                                 (#xmax,#ymax) left (-10,-22.5) right (-18,-5),
                                 (-22,43) left (3,9),
                                 (0,10),
                                 (0,0)) },
  sample-filled = { filledCurve((0,0),
                                 (23,28) left (-7,-21) right (3,9),
                                 (#xmax,#ymax) left (-10,-22.5) right (-18,-5),
                                 (-22,43) left (3,9),
                                 (0,10),
                                 (0,0))[#ntColour,#ntColour,#ntColour] },
  sample = #sample-filled + #sample-outline,
  FERN = #sample,
  FERN1 = #sample,
  FERN2 = #sample,
  FERN3 = #sample,
  FERN4 = #sample,
  FERN5 = #sample,
  FERN6 = #sample,
  
  sample-outline2 = { closedCurve((0,0),
                                 (23,32) left (-7,-21) right (3,9),
                                 (#xmax,#ymax) left (-10,-22.5) right (-18,-5),
                                 (-18,37) left (3,13),
                                 (0,0)) },
  sample-filled2 = { filledCurve((0,0),
                                 (23,32) left (-7,-21) right (3,9),
                                 (#xmax,#ymax) left (-10,-22.5) right (-18,-5),
                                 (-18,37) left (3,13),
                                 (0,0))[#ntColour * 2/3,#ntColour * 2/3,#ntColour * 2/3] },
  sample2 = #sample-filled2 + #sample-outline2,
  FERNb = #sample2,
  FERNb1 = #sample2,
  FERNb2 = #sample2,
  FERNb3 = #sample2,
  FERNb4 = #sample2,
  FERNb5 = #sample2,
  FERNb6 = #sample2,
  FERNb7 = #sample2,
  
  rect = { polygon((-4,0),(4,0),(4,16),(-4,16)) },
  tri = { polygon((-4,0),(4,0),(0,16)) },

  t1 = matrix(.85, .04, -.04, .85) . translate(0,16),
  t2 = matrix(.2, -.26, .23, .22) . translate(0,16),
  t3 = matrix(-.15, .28, .26, .24) . translate(0, 4.4),
  
  s1 = matrix(.85, .04, -.04, .85) . translate(0,16),
  s2 = matrix(.2, -.28, .26, .24) . translate(0,5),
  s3 = matrix(-.2, .28, .26, .24) . translate(0,5),
    
  fern = < #stem, t1, t2, t3 >,
  fernb = < #stem, s1, s2, s3 >
    
  }
