The Liner planning system is a prototype implementation of the linear backward chaining (LBC) planning algorithm by Bertram Fronhöfer, which is based on the linear connection method by Wolfgang Bibel. The system performs partial-order planning and includes a constraint handling interface, for example to integrate arithmetic evaluation. It runs in the SWI-Prolog environment. Outputs are represented by Prolog terms. Plans can also be displayed as images of graphs.

The system was originally written in 1999 in Eclipse-Prolog, has been ported to SWI-Prolog in 2002 and adapted to recent versions of SWI-Prolog in 2007. The performance is comparable to state-of-the-art planners around 1999. The implementation proceeds by compiling planning tasks to Prolog code, similar to the Prolog Technology Theorem Prover (PTTP) by Mark Stickel.

Liner is embedded into InfraEngine, an experimental prototype of a Semantic Web inference engine with RDF interfaces.

It is released under the GNU General Public License.


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Christoph Wernhard