applications.collages.collageAlgebra:
{
  ntColour = const(.8),

  tri = { filledPolygon((-1,0),(1,0),(0,sqrt(3)))<.5> },
  S = #tri,
  T = #tri,
   
  f1 = similarity((-1,0) -> (-1,0), (1,0) -> (0,0)),
  f2 = similarity((-1,0) -> (0,0), (1,0) -> (1,0)),
  f3 = similarity((-1,0) -> (-.5,sqrt(3)/2), (1,0) -> (.5,sqrt(3)/2)),
  f4 = scale(-1,-1) . use(f3),
  F = <f1,f2,f3,f4>,
  
  c1  = colourOperation(r|.5:0,g|.5:1,b|.5:0),
  c2  = colourOperation(r|.5:0,g|.5:0,b|.5:1),
  c3  = colourOperation(r|.5:1,g|.5:0,b|.5:0),
  c4  = colourOperation(r||.5:0,g||.5:0,b||.5:0)
}
