DECEMBER 1987 VOL. 10 NO. 4 a quarterly bulletin of the Computer Society of the IEEE technical committee on Data ri CONTENTS Letter from the Editor 1 C. Zaniolo Logic Approach to Knowledge and Data Bases at ECRC 2 H. Gal/a/re, J—M. N/colas The NU—Prolog Deductive Database System 10 K. Ramamohanarao, J. Shepherd, I. Balbin, G. Port, L. Na/sh, J. Thom, J. Zobel, P. Dart The Advanced Database Environment of the KIWI System 20 D. Sacca, M. Dispinzeri, A. Mecchia, C. Pizzuti, C. Del Gracco, P. Naggar YAWN! (Yet Another Window on Nail!) 28 K. Morris, J. Naughton, V. Saraiya, J. UI/man, A. Van Gelder A Data/Knowledge Base Management Testbed 44 R. Ramnara yen, H. Lu An Overview of the LDL System 52 0. Chimenti, T. O’Hare, R. Krishnamurthy, S. Naqvi, S. Tsur, C. West, C. Zaniolo Calls for Papers 63 SPECIAL ISSUE ON DATABASES AND LOGIC