ABSTRACT
The following article is the fourth chapter of my 1985 Ph.D. dissertation with a number of minor editorial emendations. Its academic origins will be plain to the reader in the general severity of its style and the somewhat puritanical conclusion: were I rewriting it from scratch I should attempt to make it more amiable: I hope the reader will not be discouraged. I have added a few endnotes to explain terms and notational conventions defined earlier in the thesis. But perhaps the most important theoretical issue addressed in the preceding chapters is that of hierarchical levels of serial structure. To make sense of what follows it is necessary to begin, with a summary of that theory.
