Hitherto, the three symmetric coordination types Phrasal Coordination, Right Node Raising, and Gapping have been mostly treated in isolation. This book presents a successful attempt at developing a uniform approach - couched in a transformational framework, but also applicable to other grammatical approaches. But the account not only provides a common frame for coordination. In effect, it does away with the strict distinction between simplex and coordinate structures. The proposed approach - based on a natural extension to the classical X-scheme - is equally valid for both simplex and coordinate structures, and, thus, it presents a significant contribution to grammars of phrasal structures in general.