command> ['test'] ~ {[sun]->[shines]}*{[sky]->[blue]}
  ({[sky]->[blue]}*{[sun]->[shines]})
  {[sky]->[blue]}
  {[sun]->[shines]}
  [sky]
  [blue]
  [shines]
  [sun]
command> ['test'] ~ {[sun]->[shines]}*{[sky]->[red]}
  {[sky]->[red]}
  ({[sky]->[blue]}*{[sun]->[shines]})
  ({[sky]->[red]}*{[sun]->[shines]})
  {[sky]->[blue]}
  x2 {[sun]->[shines]}
  x2 [sky]
  [red]
  [blue]
  x2 [shines]
  x2 [sun]
command> [test]*[success]*![test] # This comment is to test the preprocessor
  [success]