Learning and Solving Regular Decision Processes

Learning and Solving Regular Decision Processes

Eden Abadi, Ronen I. Brafman

Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence
Main track. Pages 1948-1954. https://doi.org/10.24963/ijcai.2020/270

Regular Decision Processes (RDPs) are a recently introduced model that extends MDPs with non-Markovian dynamics and rewards. The non-Markovian behavior is restricted to depend on regular properties of the history. These can be specified using regular expressions or formulas in linear dynamic logic over finite traces. Fully specified RDPs can be solved by compiling them into an appropriate MDP. Learning RDPs from data is a challenging problem that has yet to be addressed, on which we focus in this paper. Our approach rests on a new representation for RDPs using Mealy Machines that emit a distribution and an expected reward for each state-action pair. Building on this representation, we combine automata learning techniques with history clustering to learn such a Mealy machine and solve it by adapting MCTS to it. We empirically evaluate this approach, demonstrating its feasibility.
Keywords:
Machine Learning: Reinforcement Learning
Planning and Scheduling: Markov Decisions Processes
Knowledge Representation and Reasoning: Action, Change and Causality