nextStates :: State -> [State]
nextStates s = filter (\x -> board x /= board s) $ map (makeMove s) [0..8]
nextStates :: State -> [State]
nextStates s = filter (\x -> board x /= board s) $ map (makeMove s) [0..8]
nextStates s = filter (\x -> board x /= board s) $ map (makeMove s) [0..8]