world states. If an unsatisfied symbol exists, the effects table is examined for that world state symbol. Each action associated with the world state symbol is examined and if the action solves the unsatisfied symbol then it is considered a possible neighbour. This process continues until all possible actions have been examined for the symbol in the action effects table. Figure 9 shows the neighbours of a node being calculated during an A* search.
Figure 9 Calculation of neighbours during A* search