Before revision:  When \pi_0 is uniform random, OBL learns the optimal grounded policy . OBL can be iterated in a hierarchy, where the optimal policy from one level becomes the input to the next . This introduces counterfactual reasoning in a controlled manner.
After revision:  When \pi_0 is uniform random, OBL learns the optimal grounded policy . OBL can be iterated in a hierarchy, where the optimal policy from one level becomes the input to the next , thereby introducing multi-level cognitive reasoning in a controlled manner.