coinStart :: BelScene
coinStart = (BlS [P 0] law obs, actual) where
  law    = boolBddOf (PrpF $ P 0)
  obs    = fromList [ ("a", allsamebdd [P 0]), ("b", allsamebdd [P 0]) ]
  actual = [P 0]
coinStart :: BelScene
coinStart = (BlS [P 0] law obs, actual) where
  law    = boolBddOf (PrpF $ P 0)
  obs    = fromList [ ("a", allsamebdd [P 0]), ("b", allsamebdd [P 0]) ]
  actual = [P 0]
coinStart = (BlS [P 0] law obs, actual) where
  law    = boolBddOf (PrpF $ P 0)
  obs    = fromList [ ("a", allsamebdd [P 0]), ("b", allsamebdd [P 0]) ]
  actual = [P 0]