VAL’s Progress: The Automatic Validation Tool for PDDL2.1 used in The International Planning Competition

A key element in the success of the 3rd International Planning Competition was the implementation of an automatic plan validator for PDDL2.1 , VAL. Over 5000 plans were generated by entrants, so it was clearly essential for evaluation of the results alone. VAL was a vital tool in the development process of competitors to develop their planners. This document describes the evolution of VAL to handle more complex types of plans for competitions of the future. In the 3rd IPC the handling of numeric resources was limited in that the values could only be updated discretely. We report on the progress made with extending VAL so that numeric resources can be updated continuously. Also a new reporting option in LTEX has been implemented including a Gantt chart and graphs of the numerical resources – this greatly increases the usefulness of VAL as a tool for the development of planners using PDDL2.1.