This section contains constraint systems, constraint logic programming systems, concurrent constraint languages, and other constraint processing systems. CIAL: CIAL 1.0b is an interval constraint logic programming language. The main difference between CIAL and other CLP(Interval) languages is that a linear constraint solver, which is based on preconditioned interval Gauss-Seidel method, is embedded in CIAL in addition to the interval narrowing solver. The main motivations for a linear solver are: * Pure interval narrowing fails to narrow the intervals to any useful width even for such simple systems as {X+Y=5, X-Y=6}. Interval splitting may help but is costly. * Pure interval narrowing cannot always detect inconsistency or halt (in a reasonable time). A simple example is {A+1=D, A+B=D, A>0, B<0}. * Efficient linear constraint solver is also important to the study of efficient non-linear constraint-solving. Recent results show that interval Newton method works better than pure interval narrowing for solving non-linear constraints, but may require to solve many linear constraints in order to give the best results. This version of CIAL prototype is implemented as an extension to CLP(R) v1.2 and tested on Sun Sparc machines. You should have obtained CLP(R) from IBM prior to installing CIAL. The distribution is in the form of patches to the CLP(R) sources. [See entry on CLP(R) below]. Send email to cial@cs.cuhk.hk to request CIAL, and for more details. Relevant papers include C.K. Chiu and J.H.M. Lee, "Towards practical interval constraint solving in logic programming", in Proceedings of the Eleventh International Logic Programming Symposium, Ithaca, NY, USA, November 1994 (to appear). J.H.M. Lee and T.W. Lee, "A WAM-based abstract machine for interval constraint logic programming and the multiple-trailing problem", in Proceedings Sixth IEEE International Conference on Tools with Artificial Intelligence, New Orleans, Nov 1994. cu-Prolog: cu-Prolog is an experimental constraint logic programming language available free from Japan's Institute for New Generation Computer Technology (ICOT). Unlike most conventional CLP systems, cu-Prolog allows user-defined predicates as constraints and is suitable for implementing a natural language processing system based on the unification-based grammar. For example, the cu-Prolog developers implemented a JPSG (Japanese Phrase Structure Grammar) parser in cu-Prolog with the JPSG Working Group (the chairman is Prof. GUNJI, Takao of Osaka University) at ICOT. cu-Prolog is a complete implementation of Constraint Unification (cu), hence the name. cu-Prolog is implemented in C for BSD UNIX 4.2/3. Professor Sirai of Chukyo-University has also implemented cu-Prolog for the Apple Macintosh and DJ's GPP (80386/486 MS-DOS machine with the DOS extender). cu-Prolog is available free by anonymous ftp from ftp.icot.or.jp. For further information, send email to ifs@icot.or.jp, or write to ICOT Free Software Desk, Institute for New Generation Computer Technology, 21st Floor, Mita Kokusai Bldg., 4-28, Mita 1-chome, Minato-ku, Tokyo 108, Japan, fax +81-3-3456-1618. clp(FD): clp(FD) 2.2 is a constraint logic programming language over finite domains and booleans based on the wamcc Prolog compiler (see [2-1]). clp(FD) provides several constraints "a la CHIP" on finite domains and booleans and some facilities for building new constraints. clp(FD) is 4 times faster than CHIP v3.2 on average. clp(FD) requires GCC 2.4.5 or higher and has been tested on Sparc workstations, DEC (Ultrix), Sony MIPS (R3000), and 386/486 PCs under linux. It should be easily ported to 32-bit machines with GCC. clp(FD) is available free by anonymous ftp from ftp.inria.fr:/INRIA/Projects/ChLoE/LOGIC_PROGRAMMING/clp_fd/ For more information, write to Daniel Diaz <Daniel.Diaz@inria.fr>, INRIA Rocquencourt, FRANCE. CLP(R): CLP(R) is a constraint logic programming language with real-arithmetic constraints. The implementation contains a built-in constraint solver which deals with linear arithmetic and contains a mechanism for delaying nonlinear constraints until they become linear. Since CLP(R) subsumes PROLOG, the system is also usable as a general-purpose logic programming language. It includes facilities for meta-programming with constraints. The system consists of a compiler, byte-code emulator, and constraint solver. CLP(R) is written entirely in C and runs on Suns, Vaxen, MIPS-based machines (Decstations, Silicon Graphics), IBM RS6000s and PS2s. Includes MS-DOS support. It is available free from IBM for academic and research purposes only. To get a copy, write to Joxan Jaffar, H1-D48, IBM Thomas J. Watson Research Center, P.O. Box 704, Yorktown Heights, NY 10598, or send email to joxan@watson.ibm.com or joxan@yktvmh.bitnet. Current version 1.2. For more information, write to Joxan or Roland Yap <roland@bruce.cs.monash.edu.au>. OZ: Oz is a concurrent constraint programming language designed for applications that require complex symbolic computations, organization into multiple agents, and soft real-time control. It is based on a computation model that provides a uniform foundation for higher-order functional programming, constraint logic programming, and concurrent objects with multiple inheritance. From functional languages Oz inherits full compositionality, and from logic languages Oz inherits logic variables and constraints (including feature and finite domain constraints). Search in Oz is encapsulated (no backtracking) and includes one, best and all solution strategies. DFKI Oz is an interactive implementation of Oz featuring a programming interface based on GNU Emacs, a concurrent browser, an object-oriented interface to Tcl/Tk, powerful interoperability features (sockets, C, C++), an incremental compiler, a garbage collector, and support for stand-alone applications. Performance is competitive with commercial Prolog and Lisp systems. DFKI Oz is available for many platforms running Unix/X, including Sparcs and 486 PCs. Applications DFKI Oz has already been used for include simulations, multi-agent systems, natural language processing, virtual reality, graphical user interfaces, scheduling, placement problems, and configuration. Version 1.0 of DFKI Oz has been released on January 23, 1995. DFKI Oz is available by anonymous ftp from ps-ftp.dfki.uni-sb.de:/pub/oz or through the WWW from http://ps-www.dfki.uni-sb.de/ Tutorials, reference manuals, and research papers are available from the same locations. You may start with "A Survey of Oz" (8 pages) and continue with "An Oz Primer" (110 pages). Questions may be directed to oz@dfki.uni-sb.de. To join the Oz users mailing list, contact oz-users-request@dfki.uni-sb.de. See also ECLiPSe, Beta-Prolog, and LIFE in [2-1] and ALE in [1-5].Go Back Up