Working version. Tests to be done

README.md

+pasp V0.9
+=========
+
+(c) 2016-2017 Éric Würbel, LSIS-CNRS UMR7196
+<eric.wurbel@lsis.org>
+
+pasp is an application which implements Possibilistic Answer Set
+Programming. The semantics are those found in Bauters & al. [1]
+
+It comes with two prolog programs : `pasp` encodes the possibilistic
+normal logic program given as input into a normal logic program, which
+can be transmitted to an ASP grounder and solver (eg clingo,
+gringo+clasp, dlv, lparse+smodels...)
+
+The program `paspfilter` takes as input the output of a clingo solver
+and outputs the possibilistic stable models of the original program.
+
+Note that at this time, only normal or extended logic programs are
+handled. There are plans to implement the handling of disjunctive
+programs.
+
+See the documentation in =doc= folder for further instructions.
+
+Bibliography
+============
+
+- [1] :: Kim Bauters and Steven Schockaert and Martine De Cock and
+  Dirk Vermeir, "Characterizing and Extending Answer Set Semantics
+  using Possibility Theory", Theory and Practice of Logic Programming,
+  15(1), pp79-116, 2013
+

doc/auto/manual.el

+(TeX-add-style-hook
+ "manual"
+ (lambda ()
+   (LaTeX-add-bibitems
+    "DBLP:journals/corr/BautersSCV13")))
+

doc/manual.bib

+
+
+@article{DBLP:journals/corr/BautersSCV13,
+  author    = {Kim Bauters and
+               Steven Schockaert and
+               Martine De Cock and
+               Dirk Vermeir},
+  title     = {Characterizing and Extending Answer Set Semantics using Possibility
+               Theory},
+  journal   = {CoRR},
+  volume    = {abs/1312.0127},
+  year      = {2013},
+  url       = {http://arxiv.org/abs/1312.0127},
+  archivePrefix = {arXiv},
+  eprint    = {1312.0127},
+  timestamp = {Wed, 07 Jun 2017 14:40:39 +0200},
+  biburl    = {http://dblp.org/rec/bib/journals/corr/BautersSCV13},
+  bibsource = {dblp computer science bibliography, http://dblp.org}
+}
+

doc/pasp-manual.org

+#+TITLE: PASP V0.9
+#+AUTHOR: Éric Würbel
+#+DATE: <2018-01-19 ven.>
+#+LATEX_CLASS: scrartcl
+#+LATEX_CLASS_OPTIONS: [french,DIV15]
+#+LANGUAGE: fr
+#+LATEX_HEADER: \usepackage{lmodern}
+#+LATEX_HEADER: \usepackage{listings}
+#+LATEX_HEADER: \newcommand{\cad}{c.-à-d.{}}
+
+* Introduction
+
+  (c) 2016-2017 Éric Würbel, LSIS-CNRS UMR7296
+  <eric.wurbel@lsis.org>
+
+  pasp is an application which implements Possibilistic Answer Set
+  Programming. The semantics are those found in Bauters & al
+  \cite{DBLP:journals/corr/BautersSCV13}.
+
+  It comes with two prolog programs : `pasp` encodes the possibilistic
+  normal logic program given as input into a normal logic program,
+  which can be transmitted to an ASP grounder and solver (eg clingo,
+  gringo+clasp, dlv, lparse+smodels...)
+
+  The program `paspfilter` takes as input the output of a clingo
+  solver and outputs the possibilistic stable models of the original
+  program.
+
+  Note that at this time, only normal or extended logic programs are
+  handled. There are plans to implement the handling of disjunctive
+  programs.
+
+* Installation
+
+  PASP mainly consists in two prolog programs written for the
+  SWI-prolog compiler. It should not be complicated to port PASP to
+  other prolog systems. If you consider writing a port, please drop me a line.
+
+  At present, the installation instructions are directed toward
+  SWI-prolog installed on a linux system.
+
+  PASP consist in two different applications:
+
+  - =pasp= : a command line tool which, given an possibilistic normal
+    logic program as input, computes a corresponding normal nogic
+    program, which can be fed into an ASP grounder/solver.
+  - =paspfilter= : interprets the output of the ASP solver, and prints
+    the corresponding possibilistic answer sets.
+
+** Building the executables
+   :PROPERTIES:
+   :CUSTOM_ID: build-exec
+   :END:
+
+   The script file =build-executable.sh= is provided to build both
+   programs =pasp= and =paspfilter=. It accepts one option =-e=, which
+   effect is to incorporate SWI-prolog runtime libraries in the final
+   executable. This is actually needed for 64 bits linux systems. You
+   can omit this option if you build on a 32 bit linux system, except
+   if you plan to copy the final executables on a machine on which
+   SWI-prolog is not installed.
+
+** Installing the executables
+
+   At present there is no installation script. All you have to do is
+   to copy the executable files =pasp= and =paspfilter= in a directory
+   appearing in your =PATH=.
+
+** External programs
+
+   You need to install the =clingo= grounder/solver (4.5 and 5.x has
+   been tested). It must be present somewhere in your path.
+
+* Running pasp
+** running the command line tool
+
+   The =pasp= command line tool syntax is as follows :
+
+#+BEGIN_EXAMPLE
+pasp files...
+#+END_EXAMPLE
+
+  The files are read, and the resulting normal logic program is
+  printed on standard output.
+
+  The =paspfilter= command line tool reads the output of a clingo
+  solver on standard input and writes the corresponding possibilistic
+  answer sets on standard output.
+
+  The two programs are used in a pipeline. Suppose you want to compute
+  all the possibilistic stable models of a possibilistic normal logic
+  program contained in a file =f.pnpl=. You should run (provided that
+  the three needed programs are accessible in the PATH) :
+  #+BEGIN_EXAMPLE
+  pasp f.pnlp | clingo 0 | paspfilter
+  #+END_EXAMPLE
+
+
+
+\bibliographystyle{plain}
+\bibliography{manual}

generator.pl

@@ -100,6 +100,11 @@ necessity((H:-B),(H:-NewB),N) :-
 	flatten_conjunction(B1,NewB)
 	.
 
+%%	is_necessity(?Atom1, ?Atom2)
+%
+%	unifies Atom2 with true whenever Atom1 unifies with nec__/1.
+%	Otherwise unifies Atom1 with Atom2.
+
 is_necessity(nec__(_),true) :- !.
 is_necessity(A,A).
 

pasp.pl

@@ -35,7 +35,7 @@
 
 
 go :-
-	current_prolog_flag(argv, [_|InputFiles]),
+	current_prolog_flag(argv, InputFiles),
 	(   InputFiles = []
 	->  error("no input files")
 	;   true
@@ -54,3 +54,7 @@ test(Files) :-
 	write_conjunct(ASP,user_output)
 	.
 
+
+
+
+

postfilter.pl

@@ -147,6 +147,9 @@ result_line(end) -->
 result_line(end) -->
 	['S','A','T','I','S','F','I','A','B','L','E']
 	.
+result_line(end) -->
+	['U','N','S','A','T','I','S','F','I','A','B','L','E']
+	.
 result_line(as(AS)) -->
 	answer_set(AS)
 	.

test/test02.pl

+a :- nec__(80).
+-b :- a, nec__(80).
+c :- a, -b, nec__(70).
+d :- d, nec__(90).
\ No newline at end of file

test/test03.pl

+a :- not a, nec__(100).

test/test04.pl

+a :- not b, nec__(90).
+b :- not c, nec__(20).
+c :- not a, nec__(70).
+

test/test05.pl

+b :- not c, nec__(90).
+d :- nec__(80).
+c :- not a, nec__(80).
+e :- nec__(70).
+a :- not b, nec__(100).

test/test06.pl

+a :- b, nec__(50).
+b :- a, nec__(50).
+c :- nec__(60).
+:- c, not a, nec__(100).