Communications of the ACM (Prolog)

COMMUNICATIONS OF THE ACM December 1985 VOLUME 28, NUMBER 12 Articles -------- 1296 .... Prolog in 10 Figures (Alain Colmerauer) The theoretical model underlying logic programming in Prolog is presented in 10 sequential figures. 1311 .... Describing Prolog by its Interpretation and Compilation (Jacques Cohen) Compilation and interpretation in Prolog - posed in the context of their parallels in other languages - illustrate the advantages Prolog presents in the area of symbolic processing. Reports ------- 1326 .... Software Aspects of Strategic Defense Systems (David Lorge Parnas) A former member of an SDIO advisory panel explains why he believes we can never be sure SDI software will work. Computing Practices ------------------- 1336 .... Data Compression on a Database System (Gordon V. Cormack) General data-compression and expansion routines added to the IMS system demonstrate how a wide variety of data can be compressed using a single, fixed compression routine with almost no working storage. Research Contributions ---------------------- 1344 .... Selecting MIS Projects by Steering Committee (J.D. McKeen and Tor Guimaraes) Using a steering committee to approve MIS projects alters a very political process by changing the focus of authority and often the personnel involved, resulting in a changed portfolio of projects. Departments ----------- 1263 Authors 1265 ACM President's Letter 1271 ACM Forum 1275 From Washington 1277 Annual Report fo the Association for Computing Machinery for the Period Ending June 30, 1985 1353 Abstracts from Other ACM Publications 1355 Professional Activites 1357 Calendar of Events 1361 Call for Papers 1363 ACM News 1365 Report of the ACM Nominating Committee on Candidates for the 1986 ACM Election 1366 General News and Notes 1370 SIG Reference Guide 1372 Algorithm Index for 1985 1373 CACM Index for 1985 * Programming Pearls will return in January. The cover illustration, which is based on Alain Colmerauer's article in this issue exemplifies Prolog's use of trees as its basic data structure. In Prolog a fact is represented by a tree drawn upside down, where each leaf and node is labeled with an "atom" of information. Cover concept is by Angelica Design Group and illustration by Jo Anne Scribner