type featureFun = Board.t -> (int * int)

val stablePieces : featureFun
val cornerPieces : featureFun
val xPieces : featureFun
val pieceCount : featureFun
val moveCount : featureFun
val frontierPieces : featureFun
val edgeTraps : featureFun

val testFeatures : Board.t -> unit
