I would like to solve the Sokoban puzzle, which consists in moving a character in a 2D map to push boulders into target cells. Each turn, the player can move to an adjacent cell (no diagonals) if it is empty, or push a boulder one step further. To push a boulder, the player needs to stand next to it, and the space behind the boulder needs to be empty (no other boulders and no walls).
I'm using the STRIPS planner, and I am having a hard time defining the fixed and dynamic relations and also the preconditions and effects of each operator for this puzzle.
