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have the edges in the hashmap, and to print the edges contained in the third answer set
returned by DLV; this is an example of the print instruction, useful to understand how
the hashmap works:

	print "Edges: @{$mappedAS[2]{edge}}\n";

In this case, we are printing the array containing the predicate "edge".

=head3 getPred

Easily manage the hashmap and get the desired predicate(see the print example
described in the method above):

	my @edges = AI::Logic::AnswerSet::getPred(\@mappedAS,3,"edge");

=head3 getProjection

Returns the projection of the n-th term of a specified predicate.
Suppose that we have the predicate "person" C<person(Name,Surename);> and
that we just want the surenames of all the instances of "person":

	my @surenames = AI::Logic::AnswerSet::getProjection(\@mappedAS,3,"person",2);

The parameters are, respectively: hashmap, number of the answer set, name of the predicate,
position of the term.

=head3 statistics

This method returns an array of hashes with some stats of every predicate of every answer set,
namely the number of occurrences of the specified predicates of each answer set.
If a condition is specified(number of predicates), only the answer sets that satisfy
the condition are returned.

	my @res = AI::Logic::AnswerSet::getAS(@output);
	my @predicates = ("node","edge");
	my @stats = AI::Logic::AnswerSet::statistics(\@res,\@predicates);

In this case the data structure returned is the same as the one returned by C<mapAS()>.
Hence, for each answer set (each element of the array of hashes), the hashmap will appear 
like this:

	{
		node => 6
		edge => 9
	}

This means that for a particular answer set we have 6 nodes and 9 edges.
In addition, this method can be used with some constraints:

	my @res = AI::Logic::AnswerSet::getAS(@output);
	my @predicates = ("node,"edge");
	my @numbers = (4,15);
	my @operators = (">","<");
	my @stats = AI::Logic::AnswerSet::statistics(\@res,\@predicates,\@numbers,\@operators);

Now the functions returns the answer sets that satisfy the condition, i.e., an answer set
is returned only if the number of occurrences of the predicate "node" is higher than 4, and the number of occurrences of the predicate "edge" less than 15.

=head3 getFacts

Get the logic program facts from a file or a string.

	my @facts = AI::Logic::AnswerSet::getFacts($inputFile);

or

	my $code = "a(X):-b(X). b(1). b(2).";
	my @facts = AI::Logic::AnswerSet::getFacts($code);

DLV code can be freely exploited, with the only constraint of putting a space between rules
or facts.
This is an example of wrong input code:

	my $code = "a(X):-b(X).b(1).b(2).";

=head3 addCode

Use this method to quiclky add new code to a string or a file.

	my $code = "a(X):-b(X). b(1). b(2).";
	AI::Logic::AnswerSet::addCode($code,"b(3). b(4).");

or

	my $file = "myfile.txt";
	AI::Logic::AnswerSet::addCode($file,"b(3). b(4).");

=head3 createNewFile

Creates a new file with some code.

	AI::Logic::AnswerSet::createNewFile($file,"b(3). b(4).");

=head3 addFacts

Quiclky adds facts to a file. Imagine to have some data(representing facts) 
stored inside an array; just use this method to put them in a file and give it a name.

	AI::Logic::AnswerSet::addFacts("villagers",\@villagers,">","villagersFile.txt");

In the example above, "villagers" will be the name of the facts; C<@villagers> is the array 
containing the data; ">" is the file operator(will create a new file, in this case); 
"villagersFile.txt" is the filename. The file will contain facts of the form "villagers(X)",
for each "X", appearing in the array C<@villagers>.


=head1 SEE ALSO

www.dlvsystem.com

=head1 AUTHOR

Ferdinando Primerano, E<lt>levia@cpan.orgE<gt>
Francesco Calimeri, E<lt>calimeri@mat.unical.itE<gt>

This work started within the bachelor degree thesis program of the
Computer Science course at Department of Mathematics of the University
of Calabria.

=head1 COPYRIGHT AND LICENSE