 So the Traditional Scheme rests squarely on the soundness of NC, along with \(\OB\)-RE and the TDS. In fact, the Traditional Scheme can be seen as a widely endorsed, informal counterpart of a deontic logic composed of just PC, \(\OB\)-RE and NC. Since that logic is a (proper) fragment of SDL, it follows that the Traditional Scheme (symbolized) is entailed by  SDL.[27]