Haskell implementation of Oleg's embedded probabilistic programming.
http://okmij.org/ftp/kakuritu/#derivation

DSL(5 versions)
  SearchTree0.hs  Tree Search
  SearchTree.hs   Tree Search / Monad
  CPS0.hs         CPS
  CPS.hs          CPS / Monad
  Direct.hs       Delimited Continuation / Monad

Model
  Lawn.hs         Wet Grass
  CoinToss.hs     Coin Toss
  (*) Select DSL by commenting out the import statement.