fn(z*z) cosh       {
  reset type=fn(z*z) function=cosh corners=-4.0/3.997803/-2.99585/3.0
  potential=255/200/200
  colors=000z60<6>z10z00z00y00<80>10x10x00y00y11x<77>vv3ww2xx1yy1yy0zz0<75>z70
  }