Contributions of Ronald V. Book to the Theory of String-Rewriting Systems Robert McNaughton Ron Book's interest in string-rewriting systems was stimulated by Maurice Nivat [12], who, in the 1970's, investigated Thue systems [15] and semi-Thue systems for applications to formal languages and algebra. The collection of research problems that Book was to focus on in the 1980's was, to a large extent, an outgrowth of the collection of problems that Nivat and his collaborators had focused on in the 1970's (see Berstell's 1977 paper [1]). During most of the 1980's Book was intensively interested in research in this area. He is to be lauded for carrying out his research on a broad front, maintaining an interest in several different research questions, developing his own thoughts and paying careful attention to the results of others. He had many research collaborators, including several doctoral students and people who spent some fruitful post-doctoral years at Santa Barbara. He was, in effect, the leader of a group that included all or most of these. Part of our appreciation of the impact that he had on the field of rewriting systems was what these students and post-docs went on to do after they left Santa Barbara. I would like to interject a personal remark at this point and mention how much I have gained from this group. I have profited not only from the clear research orientation that Book has provided, but also from the contact I have had with him and with those who have acquired this orientation from him. Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY cs-96-19
Contributions of Ronald V. Book to the Theory of String-Rewriting Systems
Robert McNaughton
Ron Book's interest in string-rewriting systems was stimulated by Maurice Nivat [12], who, in the 1970's, investigated Thue systems [15] and semi-Thue systems for applications to formal languages and algebra. The collection of research problems that Book was to focus on in the 1980's was, to a large extent, an outgrowth of the collection of problems that Nivat and his collaborators had focused on in the 1970's (see Berstell's 1977 paper [1]). During most of the 1980's Book was intensively interested in research in this area. He is to be lauded for carrying out his research on a broad front, maintaining an interest in several different research questions, developing his own thoughts and paying careful attention to the results of others. He had many research collaborators, including several doctoral students and people who spent some fruitful post-doctoral years at Santa Barbara. He was, in effect, the leader of a group that included all or most of these. Part of our appreciation of the impact that he had on the field of rewriting systems was what these students and post-docs went on to do after they left Santa Barbara. I would like to interject a personal remark at this point and mention how much I have gained from this group. I have profited not only from the clear research orientation that Book has provided, but also from the contact I have had with him and with those who have acquired this orientation from him.
Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY
cs-96-19