More Webpages, Publications, and Code related to IPP 1.0 to 4.1

• RIFO: removing irrelevant operators and facts from planning problems.
• GAM: IPP's Goal Agenda Manager to order sets of subgoals and incrementally plan for subproblems.
• XGV 1.1: the graphical interface for the inspection of planning graphs on SUN workstations. Requires certain Motif libraries, which are almost nowhere available. Here is XGV for PC under Linux (statically linked and compiled). XGV documentation.
• Syntax for operators and factfiles for IPP 1.0 and IPP 2.0.
• Syntax for operators and factfiles for IPP 3.0 to IPP 3.3.
• IPP 3.3 in the first international planning competition 1998.

• J. Koehler, B. Nebel, J. Hoffmann, Y. Dimopoulos: Extending Planning Graphs to an ADL Subset, ECP-97, pages 273-285, Springer LNAI 1348, 1997.

• Technical report 88/97: A more detailed description of the backward search algorithm to handle conditional effects, proofs, more examples, and a detailed empirical evaluation of IPP 2.0 including a comparison to UCPOP and PRODIGY. The UCPOP domains and Prodigy domains used for comparison in the IPP report can also be downloaded.

• B. Nebel, Y. Dimopoulos, J. Koehler: Ignoring Irrelevant Facts and Operators in Plan Generation, ECP-97, pages 338-350. The original RIFO paper.

• J. Koehler: RIFO within IPP, Technical Report 126/99, which describes the use of RIFO within IPP.

• J. Koehler: Solving Complex Planning Tasks Through Extraction of Subproblems, AIPS-98, pages 62-69. The initial GAM paper. An extended version is available as Technical Report 110/98. A much improved theoretical framework analyzing goal orderings is the following article for the Journal of Artificial Intelligence Research.

• J. Hoffmann, J. Koehler: A new Method to Query and Index Sets, IJCAI-99, pages 462-467. The paper describing UBTREE, IPP's implementation of subset memoization using extended Radix Trees.The Technical Report 108/99 is a slightly extended version.

• J. Koehler: Planning under Resource Constraints, ECAI-98, pages 489-493. This paper describes an attempt of defining a useful representation language to handle resource information in planning problems and gives an outline of the algorithm that is partially implemented in RIPP 0.1. It has inspired some more work into this direction.

• J. Koehler: Metric Planning using Planning Graphs - A First Investigation. The Technical Report 127/99 gives a clean definition of a sound and complete backward searching algorithm to handle simple resource effects in planning graphs. It has never been implemented in IPP.

• J. Koehler: Handling of Conditional Effects and Negative Goals in IPP. The Technical Report 128/99 describes how the graph is built implicitely by generating only a single action and fact layer and how the backward search algorithm works.

• J. Koehler, J. Hoffmann: Handling of Inertia in a Planning System. The Technical Report 122/99 describes IPP's approach to generate a compact and normalized instantiation of general ADL operators.