Constructing action graphs for planning

The problem of planning in a world can be seen as the problem of determining a sequence of world changes which allows to reach a goal state from a given initial state, each world change being caused by an action. We present here a planning system which is constructed on a logical action formalism, where actions are pairs of formulas (precondition, result). The precondition describes what has to be true in a state for an action to be performed; the result describes what will be true in a state after the execution of the action. Actions occur in worlds which are also determined by general laws which remain always true throughout the changes. These general laws de ne which are the states possible for a world. These possible states can be obtained from the implicants of the general laws. Given a planning problem, we show how to obtain, without backtracking, a graph representing the minimal solutions for it. keywords: Deductive planning, action theory, persistencies, shortest path search, subgraph computation.