Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!rutgers!mit-eddie!genrad!decvax!ucbvax!SCORE.STANFORD.EDU!PROLOG-REQUEST From: PROLOG-REQUEST@SCORE.STANFORD.EDU.UUCP Newsgroups: comp.lang.prolog Subject: PROLOG Digest V5 #7 Message-ID: <8702092110.AA22540@ucbvax.Berkeley.EDU> Date: Sun, 8-Feb-87 07:38:00 EST Article-I.D.: ucbvax.8702092110.AA22540 Posted: Sun Feb 8 07:38:00 1987 Date-Received: Wed, 11-Feb-87 05:11:59 EST Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: PROLOG@SU-SCORE.ARPA Organization: The ARPA Internet Lines: 143 PROLOG Digest Monday, 9 Feb 1987 Volume 5 : Issue 7 Today's Topics: Query - Debugging & Conference Proceedings, Announcement - Dissertation available, Implementation - Debugging ---------------------------------------------------------------------- Date: 28 Jan 87 05:01:56 GMT From: cybvax0!frog!primerd!bob@EDDIE.MIT.EDU Subject: Debugging I'm doing some research on debugging techniques, and I'm interested in the special kinds of bugs a Prolog programmer encounters. (There are obviously some things about Prolog which make it unique in this respect.) I'd like to hear about problems people have had, and how they uncovered them. Bug stories are always interesting. I'd also like to hear your opinion about what sort of tools would make Prolog debugging easier. -- Bob Pellegrino Prime Computer ------------------------------ Date: 27 Jan 87 11:34:27 GMT From: mcvax!kddlab!titcca!kossvax!koeavax!yang@seismo.css.gov Subject: I will be pleased to send my dissertation (about P-Prolog) on request (In English) Hello, I'm a Ph.D student, majoring in logic programming, at Keio University. I have just finished writing my doctoral dissertation titled 'A Parallel Logic Programming Language and Its Implementation'. You can find an abstract of my dissertation in the rest this message. Does anybody have an interest in it? I'd like to send you a copy upon your request. I'm sorry that I will basically send it by sea mail because of a financial reason. If you'd like to read it as soon as possible, please mention this in your reply and send me about $15. Then, I will be able to send you in air mail. I look forward to hearing from you ! Thanks you. -- Rong Yang ------------------------------------------------------------------------------ My mail address: | My net mail address: | Rong Yang | yang%keio.junet@utokyo-relay Aiso Lab | Dept. of Electrical Engineering| or Keio University | 3-14-1 Hiyoshi, Yokohama 223 | ..!mcvax!kddlab!titcca!kossvax!koeavax!yang JAPAN | ------------------------------------------------------------------------------ Abstract This dissertation presents a parallel logic programming language named P-Prolog, and discusses its implementation. To date, two main research areas for parallel logic programming have been studied: (1). To develop methods, or control strategies, for executing pure Horn clause programs in parallel. (2). To develop new parallel languages based on guarded Horn clauses, and implementation methods for them. For (1), it is likely that to execute pure Horn clause programs with both and-parallelism and or-parallelism is quite difficult, so restrictions are usually imposed. The drawback with (2) is that guarded Horn clause languages sacrifice completeness, because they do not incorporate don't-know non-determinism. This dissertation presents an alternative proposal, P-Prolog, which provides the advantages of guarded Horn clauses while retaining don't-know non-determinism where required. P-Prolog programs are composed of a kind of extended guarded Horn clauses called classified Horn clauses} which are introduced in this dissertation. A novel concept introduced in classified Horn clauses is the exclusive relation of guarded Horn clauses. Two advantages resulting from the introduction of classified Horn clauses are: (1). The language combines and-parallelism and or-parallelism. Therefore the execution of P-Prolog can incorporate both don't-care non- determinism and don't-know non-determinism. (2). The input/output pattern of predicates need not be fixed. Its synchronization mechanism allows the direction of data flow to be determined dynamically. In terms of implementation, combining and- and or- parallelism is regarded as a difficult subject. This dissertation presents an or-tree model and an implementation scheme for it, to combine these kinds of parallelism with reasonable efficiency. The model and implementation scheme discussed in this dissertation can be applied not only to P-Prolog, but also to other parallel logic languages. This dissertation is divided into two parts: language and implementation. In Part I, a brief review of the theory of logic programming and a survey of parallel logic languages are first given; then the concepts, syntax, semantics and characteristics of P-Prolog are described. In Part II, the three main problems of implementation are discussed: representation of data, management of multiple environments and communication between and-processes and or-processes. ------------------------------ Date: 3 Feb 87 11:05:21 GMT From: Bruce T. Smith Subject: 2nd International Logic Programming Conference? Does anyone know how to get the proceedings from the Second International Conference (Uppsala, SWEDEN, in July, 1984)? I've seen the 1st (Marseille, FRANCE, in September, 1982), and the 3rd is a Springer LNCS. The Second, however... Thank you. -- Bruce T. Smith ------------------------------ Date: 2 Feb 87 16:15:18 GMT From: Peter Y.F. Wu Subject: Debugging Typo is a common mistake. When that happens with the functor name of a predicate, it results in undefined predicates in the Prolog program. It may be nice for a Prolog system to *optionally* flag undefined predicates so that one does not have to trace it all the way to realize it is a typo in the functor name. It has to be optional since undefined predicate may be a deliberate feature to generate failure. -- Peter Y.F. Wu ------------------------------ End of PROLOG Digest ********************