Used by the routine at ADJ_FOR_OUT_OF_BOUNDS.

ADJ_DU_FOR_OBJ_INTERSECT for Z, done before U and V so it tests the object where it stands: an object has to overlap in U and in V to be above or below it. Stopping sets bit 2 of +$0C, whether the move was up or down, and harm passes as in U.

A mover with bit 2 of its flags -- the robot's legs have it -- is carried: it gives its intended dZ to the obstacle and, wherever its own dU or dV is zero, takes on the obstacle's, so standing on something that moves carries it along. When that mover is one of graphics 16 to 47, which takes in the robot's legs, the obstacle also gets bit 3 of its +$0D: the robot has stood on it, or come up against it from below. The update routines of graphics 44, 45 and 47 (DROPPING_BLOCK, COLLAPSING_BLOCK, LIFT) read and clear that bit.

Knight Lore sets the obstacle's bit 3 for any mover and passes no dZ; Pentagram passes the dZ and sets bit 3 for any mover too, with more of its own (the conveyors, the marks its lift reads). Here the bit is kept for the robot.