Pove the pruning strategy for the range query below (Hint: use the triangle inequality) [30 points]:

If |d(O_p, Q)-d(O_r, O_p)|>r(Q)+r(O_r), then d(O_r, Q) > r(Q) + r(O_r) holds and node centered at O_r with radius r(O_r) can be safely pruned.