Structural Frameworks with Higher-Level Rules

Read and Neil Tennant for helpful comments and discussions on topics related to this work. Drafts of Chapters 5 and 6 were written during a research stay at the Department of Logic and Metaphysics of the University of St. Andrews in Spring 1985. I am grateful to the Fritz Thyssen Stiftung for supporting this stay with a travel grant. I should like to thank my colleagues, especially Gereon Wolters, for contributing to a congenial and stimulating atmosphere at the Department of Philosophy here in Konstanz. In particular, I wish to express my appreciation to Jürgen Mittelstraß for continuously supporting me in my work and giving me the opportunity to pursue the research interests that resulted in this study. Finally, a note of thanks to Ron Feemster and especially to Raoul Eshelman for revising the English manuscript. Added 2003: I am very grateful to Thomas Piecha for converting the original file into L A T E X. He carried out this tedious task with extreme diligence. Concerning the content of this work I should mention that the logical system of positive relevance logic arrived at in Chapter 5 is not R, as claimed on p. 48, but the system RM of relevance logic with the mingle rule.