Answer to Exercise 7

| ANSWER TO EXERCISE 7
    [ SwapDirs o1 o2 x;
      x=o1.door_dir; o1.door_dir=o2.door_dir; o2.door_dir=x; ];
    [ ReflectWorld;
      SwapDirs(e_obj,w_obj); SwapDirs(ne_obj,nw_obj); SwapDirs(se_obj,sw_obj);
    ];

Back to the exercise in section 10

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