In this chapter, we’ve seen JDs implying JDs; a JD and an FD together implying an FD; FDs implying a JD; and, in earlier chapters, FDs implying FDs. However, note carefully that all the chase lets us do is determine whether a specific dependency follows from given dependencies. What it doesn’t do is let us infer, or generate, new dependencies from the given set (that’s why I said, near the beginning of the previous section, that the chase provided only a partial answer to the question). For that, we’d need an axiomatization for FDs and JDs. And while Armstrong’s rules provide a sound and complete axiomatization for FDs by themselves, it’s unfortunately a known fact that no such axiomatization exists for FDs and JDs considered together.^[112]