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				WORKFLOW


			     Torsten Schaub
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Table of Contents
─────────────────

1 Process
2 Problem
3 Modeling
.. 3.1 Problem instance
..... 3.1.1 Commands
.. 3.2 Problem class
..... 3.2.1 Commands
4 Grounding
.. 4.1 NB: You may as well want to try gringo 3 for more options:
5 Solving
6 Miscellaneous
.. 6.1 Alternative encoding
.. 6.2 clingo versus gringo+clasp


The ASP solving process Graph coloring

Torsten Schaub, torsten@cs.uni-potsdam.de

[http://potassco.sourceforge.net/videos.html]


1 Process
═════════

  okular –presentation asp-solving.pdf


2 Problem
═════════

  • [http://en.wikipedia.org/wiki/Graph_coloring]
  • Example: Graph coloring, Section 3.1 in [1]

  • Given a graph consisting of nodes and edges, assign each node one
    color such that no two nodes connected by an edge have the same
    color


3 Modeling
══════════

3.1 Problem instance
────────────────────

  A *graph* consisting of nodes and edges, along with some colors, is
  represented as
  • facts formed by predicates node/1 and edge/2
  • facts formed by predicate col/1


3.1.1 Commands
╌╌╌╌╌╌╌╌╌╌╌╌╌╌

  view-file [graph.lp]


  [graph.lp] file:graph.lp


3.2 Problem class
─────────────────

  Assign each node one color such that no two nodes connected by an edge
  have the same color

  In other words:

  • Each node has a unique color
  • Two connected nodes must not have the same color


3.2.1 Commands
╌╌╌╌╌╌╌╌╌╌╌╌╌╌

  view-file [color.lp4] [2]

  okular –presentation methodology.pdf


  [color.lp4] file:color.lp4


4 Grounding
═══════════

  gringo4 –version

  • _human-readable output_ gringo4 color.lp4 graph.lp –text

  • _machine-readable output_ (see Table 7.1 in [1]) gringo4 color.lp4
    graph.lp


4.1 NB: You may as well want to try gringo 3 for more options:
──────────────────────────────────────────────────────────────

  view-file [color.lp4] [2] view-file [color.lp]

  gringo3 color.lp graph.lp –text

  gringo3 color.lp4 graph.lp –text gringo4 color.lp4 graph.lp –text


  [color.lp4] file:color.lp4

  [color.lp] file:color.lp


5 Solving
═════════

  clasp3 –version

  gringo4 color.lp4 graph.lp | clasp3 gringo4 color.lp4 graph.lp |
  clasp3 0

  gringo4 color.lp4 graph.lp | clasp3 0 –stats


6 Miscellaneous
═══════════════

6.1 Alternative encoding
────────────────────────

  view-file [colorD.lp4] [2]

  gringo4 colorD.lp4 graph.lp –text gringo4 colorD.lp4 graph.lp | clasp3
  0


  [colorD.lp4] file:colorD.lp4


6.2 clingo versus gringo+clasp
──────────────────────────────

  clingo4 –version

  clingo4 color.lp4 graph.lp

  clingo4 –help
  • "–help=3" clingo4 –help=3
  • "–mode" clingo4 –mode=gringo color.lp4 graph.lp | clingo4
    –mode=clasp



Footnotes
─────────

[1] M. Gebser, R. Kaminski, B. Kaufmann, and T. Schaub.  Answer Set
Solving in Practice.  Synthesis Lectures on Artificial Intelligence
and Machine Learning, Morgan and Claypool December 2012, 238 pages,
[doi:10.2200/S00457ED1V01Y201211AIM019]

[2] We use extension lp4 to indicate encodings for gringo 4 (along the
ASP-Core-2 standard [3])

[3] F. Calimeri, W. Faber, M. Gebser, G. Ianni, R. Kaminski,
T. Krennwallner, N. Leone, F. Ricca, and T. Schaub: ASP-Core-2: Input
language format. 2012.  Available at
[https://www.mat.unical.it/aspcomp2013/files/ASP-CORE-2.0.pdf].