XD1LP: An XSB implementation of D1LP

This is XD1LP, an XSB implementation of D1LP.  This is the version 
as of July, 2000.  

Click here to download.

The downloaded zip file consists of the following files:

    Main.P          the parser (using DCG), meta-interpreter, top-level 
                    predicates for loading D1LP rules, and predicates that 
                    load existing examples and sample queries
    Tokenizer.P     the lexical scanner
    Compiler.P      the transformer from internal representation of D1LP
                    rule to that of OLP 
    Library.P       rules that implement inferencing involving threshold 
                    structures, conjunctions and disjunctions in principal 
                    structures; these rules are used by the meta-interpreter 
    examples/       the directory that contains some examples

    TopLevelWindow.java   This is not part of XD1LP.  It is my modified 
                    version of the same file in InterProlog. 

XD1LP needs XSB 2.1 or higher to run.  XSB is available from
http://www.cs.sunysb.edu/~sbprolog/xsb-page.html

The implementation reads in a file that is a D1LP program, and then
answers queries.  Example queries are in the file main.P.  The
example D1LP programs are under the directory examples.

You need to replace every occurrence of c:\work\dl in main.P with where
you extract all the files to.  Then start XSB, and type
consult('path_to_main.P').  Then you can type test1 to load first
example and type different queries, e.g, query01(S).

This is developed under Win32 platform.  To use it under Unix, you need
to change the path separator "\" to "/".

Todo list:
1. Currently one has to type OLP queries directly.  It would be desirable 
   to handle D1LP queries directly.  
2. The syntax needs to be extended to allow "A delegates ?P^1 to B,'' 
   which means A delegates every predicate to B.  This should be 
   just a matter of changing the DCG grammar. 
3. A better way to distinguish all principals from other terms is needed. 

To actually use this XSB implementation in other applications, you
probably need interface between XSB and other languages.  Such info
is available from XSB's web site.  

InterProlog, a Java-to-Prolog interface is available from  
http://dev.servisoft.pt/interprolog/
To quote from the website:
    "First, InterProlog provides a simple facelift to Prolog, by running 
    it under a separate process and redirecting its STDIO to a Java 
    window. But it also provides Prolog with the ability to call any 
    Java method, and for Java to invoke Prolog goals, by using standard 
    TCP/IP sockets to pass object/term data among both processes."
The current version of InterProlog (as of August 2000) is 1.0b3 (released 
in December, 1999).  Somehow, the jar file didn't work on my environment.  
But it worked when I compiled the source file and used the class files 
directly.  I use InterProlog as a GUI to XSB.  Because I use it quite 
often, I modified the pt.servisosft.interprolog.gui.TopLevelWindow 
class to 
(1) allow one to use up arrow and down arrow to access command history 
(2) make the history menu an 20-item window.  Otherwise, the menu keep 
    growing until one can not see the most recent commands
(3) and make the history menu do not store short commands (one or two 
    characters).  Otherwise, during debugging, these short commands quickly
    take up all spaces in history menu, making the history menu useless. 
The new file is also included in this package.  You can use it to replace 
the original file in InterProlog 1.0b3.

Please send questions and suggestions to ninghui@cs.nyu.edu