support at -3 and -1, 3 kg block at -4
3 kg at 0, effectively (due to board)
torque at a given point:
 out_torque(dw) = d * w [ distance from closest support * weight ]
 in_torque(dw) = 

 out_torque - in_torque (calc for each support, if both same sign, tip).
 if out_torque on left post is positive, tip. if in_torque on right post is neg, tip. (?)

Better pruning! see adversarysearch.pdf
Effective fanout is only half of what it would be (with pruning?)