However, estimating and optimizingα-divergences require to use importance sampling, which may havelarge orinfinite variance due to heavy tails ofimportance weights.

While it is well suited to describe turn-based decision problems such as board games, this framework is ill suited for real-time applications in which the environment's state continues to evolve while the agent selects an action (Travnik et al., 2018). Nevertheless, this framework hasbeen used forreal-time problems using what areessentially tricks, e.g.

Here, we focus on a more practical setting in object rearrangement,i.e., rearranging objects from shuffled layouts to a normative target distribution without explicit goal specification. However, it remains challenging for AI agents, as it is hard to describe the target distribution (goal specification) for reward engineering or collect expert trajectories as demonstrations. Hence, it is infeasible to directly employ reinforcement learning or imitation learning algorithms to address the task. This paper aims to search for a policy only with a set of examples from a target distribution instead of a handcrafted reward function. We employ the score-matching objectiveto train aTargetGradientField (TarGF),indicating a direction on each object to increase the likelihood of the target distribution.

Ontheotherhand,asintelligentagents,humansusuallyspendlesstime learning similar tasks and can acquire new skills using existing ones.

Based on our regularization, we propose an off-policy actor-critic algorithm.

In BW, an include: areforwardprogress, failur ), acostcontr ), ashapingrehead). Require:Experience B; twinQ-function 1, 2 (with parameters 1, 2; policyparameter ; discount ; entrop ; learningrates q, ; targetnetw ; Boolean 1: Sampletransition(s, a, r,0) B.r2Rm is 2: Samplepolica0 ( |s0; )andu ( |s; ) 3: rm+1 log (a0|s0; ).Extend 4: j argmin