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Clipper Reasoner

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Clipper is a DL reasoner for conjunctive query answering over Horn-SHIQ ontology via query rewriting.

Build from source

We use maven build system and Git to manage the source code.

  $ git clone clipper
  $ cd clipper
  $ ./

Usage from CLI

  1. Download DLV to your local machine (e.g., to ~/bin/dlv).

  2. Run from the generated package.

Usage: [options] [command] [command options]
    -v, -verbose   Level of verbosity
                   Default: 1
    query      answerting conjunctive query
      Usage: query [options] <ontology.owl> -sparql <cq.sparql>    
          -f, --output-format   output format, possible values: { table | csv |
                                atoms | html }
                                Default: table
          -dlv                  the location of dlv (e.g. /usr/local/bin/dlv)

    rewrite      rewrite the query w.r.t. the ontology, and generate a datalog program
      Usage: rewrite [options] <ontology.owl> [ -sparql <cq.sparql> ]       
          --abox-only, -a             only rewrite ABox
                                      Default: false
          --ontology-and-query, -oq   rewrite ontology (= TBox + ABox) and query
                                      Default: false
          --ontology-only, -o         only rewrite ontology (= TBox + ABox)
                                      Default: false
          --remove-redundancy, -r     remove redundancy rules w.r.t the query
                                      Default: false
          --tbox-and-query, -tq       only rewrite TBox and query
                                      Default: false
          --tbox-only, -t             only rewrite TBox
                                      Default: false
          -output-datalog, -d         output datalog file 

    help      Print the usage
      Usage: help [options]

Development in Eclipse

  1. Download the source code via git.
  2. In eclipse, import the project by "File" -> "Import" -> "Maven" -> "Existing Maven Projects" and point to root directory of clipper.


[1] Thomas Eiter, Magdalena Ortiz, Mantas Šimkus, Trung-Kien Tran, and Guohui Xiao. Query Rewriting for Horn-SHIQ plus Rules. In Proceedings of the Twenty-Sixth AAAI Conference on Artificial Intelligence (AAAI 2012), July 22-26, 2012, Toronto, Ontario, Canada. AAAI, AAAI Press, 2012.. pdf

[2] Thomas Eiter, Magdalena Ortiz, Mantas Šimkus, Trung-Kien Tran, and Guohui Xiao. Towards Practical Query Answering for Horn SHIQ. T. In Y. Kazakov, D. Lembo, and F. Wolter, editors, Proceedings of the 2012 International Workshop on Description Logics, DL-2012, Rome, Italy, June 7-10, 2012, volume 846 of CEUR Workshop Proceedings., 2012. pdf


Contact: xiao(a)


A Reasoner for Conjunctive Query Answering over Horn-SHIQ via Query Rewriting



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