DES 1.5.0 Released

[Apologies for multiple receptions]

Hello.
This is a mail just for informing that the new release

  Datalog Educational System version 1.5.0
  http://des.sourceforge.net

has been launched on 30th, December, 2007 and ported to 

  GNU Prolog 1.3.0

Release notes are attached to the end of this message.
Please, see http://des.sourceforge.net for details.

  Best regards.

==============================================================
Fernando Sáenz Pérez
Profesor Titular de Universidad / Associate Professor
Home Page: http://www.fdi.ucm.es/profesor/fernan
Tel: + 34 913947642. Fax: + 34 913947547
Despacho / Office: 435 (4ª planta / 4th floor)
Dept. Ingeniería del Software e Inteligencia Artificial / 
Department of Software Engineering and Artificial Intelligence
Universidad Complutense de Madrid
Facultad de Informática
C/Profesor José García Santesmases, s/n
E - 28040 Madrid. Spain
==============================================================



Version 1.5.0 of DES adds to previous version (1.4.0):

Enhancements:
    o    A more fine-grained debugging as long as individual clauses can be inspected
    o    Warning and error messages provided for: 
        §    Undefined predicates which are called by rules each time the database is changed
        §    Unsafe rules
        §    Execution exceptions known at compile-time
    o    Exception messages provided for: 
        §    Execution exceptions unknown at compile-time
    o    Rule transformation for allowing computation of safe rules which may raise run-time exceptions due to built-ins
    o    Rejection of unsafe or uncomputable queries, views and autoviews
    o    Catching of instantiation errors
    o    Rule source annotated for debugging and informative errors, i.e., file and lines in the program (if consulted) or assertion time (if manually asserted)
    o    Elapsed time display
    o    New basic, simpler (although less efficient than the already implemented) algorithm for computing stratified negation, following [SD91]
    o    Fresh variables are given new variable names instead of numbers
    o    New commands:
        §    /negation Displays the selected algorithm for solving negation
        §    /negation Algorithm Sets the required Algorithm for solving negation (strata or et_not)
        §    /timing Displays whether elapsed time display is enabled
        §    /timing Switch Enables or disables elapsed time display (on or off, resp.)
        §    /safe  Displays whether program transformation is enabled
        §    /safe Switch Enables or disables program transformation (on or off, resp.)
    o    Changed commands: 
        §    /verbose Displays whether verbose output is enabled
        §    /verbose Switch Enables or disables verbose output messages (on or off, resp.)
    o    Deprecated commands: 
        §    /noverbose 
    o    Slight modifications on existing commands: 
        §    /debug Goal Level The inspection level can be set with the second optional argument with p for predicate level and c for clause level
        §    /status Now, it also displays the selected algorithm for negation and whether program transformation is enabled
        §    /version For matching the ‘standard’ display
    o    New examples added to the directory examples
    o    The Prolog database corresponding to the Datalog loaded programs has been discarded, therefore using only one representation for them
    o    Revised and upgraded user’s manual

Changes:
    o    Inequality built-ins cause an error and stops execution whenever they are computed with any non-ground argument (formerly, they silently failed)

Fixed bugs:
    o    The Linux version did not work. Now, it has been fixed and tested on Ubuntu 6.10, Kubuntu 7.04 (Feisty), and Mandriva Linux 2007 Spring
    o    The parser did not detect that the argument of not could be a variable
    o    Name clashes when loading programs and asserting rules are avoided