Datalog Educational System Files

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  | DES INSTALLATION (quick guide) |
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Windows Binary Distribution with ACIDE GUI
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- Double-click on des_acide.jar for starting the 
  ACIDE GUI

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Windows Binary Distribution
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- Double-click on deswin.exe for starting the Windows
  application
- Execute des.exe for starting the console application

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Linux/MacOSX Binary Distribution with ACIDE GUI
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- Add execute permission to file des, typically with:
  chmod +x ./bin/des
  or from the file explorer.
- Start ACIDE from a terminal with:
  java -jar des_acide.jar  

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Linux/MacOSX Binary Distribution
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- Add execute persmission to file des, typically with:
  chmod +x ./des
  or from the file explorer.
- Start ./des in a terminal from its installation path

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Windows Source Distributions
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1. Create a shortcut in the desktop for running the Prolog 
   interpreter of your choice. 
2. Modify the start directory in the "Properties" dialog box 
   of the shortcut to the installation directory for DES. 
   This allows the system to consult the needed files at startup.
3. Append the following options to the Prolog executable complete 
   filename, depending on the Prolog interpreter you use:
   (a) SICStus Prolog: -l des.pl
   (b) SWI Prolog: -g "ensure_loaded(des)" (remove --win_app if 
     present)
Another alternative is to write a batch file similar to the 
script file described just in the above section.
    
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Linux/MacOSX Source Distributions
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You can write a script for starting DES according to the 
selected Prolog interpreter, as follows:
(a) SICStus Prolog: 
    $SICSTUS -l des.pl 
    Provided that $SICSTUS is the variable which holds 
    the absolute filename of the SICStus Prolog executable.
(b) SWI Prolog: 
    $SWI -g "ensure_loaded(des)"
    Provided that $SWI is the variable which holds the 
    absolute filename of the SWI Prolog executable.

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More Information: 
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- See User Manual
  'Documentation' entry in 
  http://www.fdi.ucm.es/profesor/fernan/des/html/download.html
- http://des.sourceforge.net


Version Devel of DES (released on February, 25th, 2016)
 
* Enhancements:
  o New formal languages with syntax and safety checking::
    * Domain relational calculus (DRC)
    * Tuple relational calculus (TRC)
  o New Datalog existential quantifier provided with the metapredicate
    exists(Vars,Goal)
  o Pointing to the location where an unbalanced bracket is found
  o Improved some SQL syntax error messages
  o Improved unfolding for more simplified compilations
  o Unsafe calls including a negated goal with unrestricted variables 
    that can be made safe are processed by safety transformations, 
    therefore sugaring syntax for neater formulations
  o Unrestricted, underscored variables are assumed to be existential 
    variables if not occurring in the head
  o Left operand of is is checked to be either a variable or number
  o New commands:
    * /drc Switch to DRC interpreter
    * /drc Query Execute a DRC query
    * /trc Switch to DRC interpreter
    * /trc Query Execute a TRC query


* Changes:
  o 
  
* Fixed bugs:
  o RA listings failed due to a non-existent predicate.
  o An identifier starting with not would be split into a not 
    metapredicate and the rest of the identifier.
  o Listings of RA view definitions with /dbschema failed (bug 
    introduced in version 3.11)
  o Added error message for schema with no column.
  o A view with the name and arity of a Datalog built-in could be 
    created.
  o Modes were not updated when retracting rules by identifier.
  o Negated literals as metapredicate arguments were required to be 
    delimited between parentheses
  o Operators with textual names required blanks surrounding them
  o Compilation of some logical expressions including and, or and not 
    were not correct due to operator precedence and associativity