nodeCondEntropy :: (Floating prob, Ord prob, Ord a)
                   => [String]
                   -> [String]
                   -> ModelDistribution prob a
                   -> prob
nodeCondEntropy yv xv m =
  let p_ygx = extractC $ conditionalize yv xv m
      p_x = extract $ marginalize xv m
  in condEntropy p_ygx p_x
nodeCondEntropy :: (Floating prob, Ord prob, Ord a)
                   => [String]
                   -> [String]
                   -> ModelDistribution prob a
                   -> prob
nodeCondEntropy yv xv m =
  let p_ygx = extractC $ conditionalize yv xv m
      p_x = extract $ marginalize xv m
  in condEntropy p_ygx p_x
nodeCondEntropy yv xv m =
  let p_ygx = extractC $ conditionalize yv xv m
      p_x = extract $ marginalize xv m
  in condEntropy p_ygx p_x