Modular Constraint Solver Cooperation via Abstract Interpretation
University of Angers（昂热大学）；University of Nantes（南特大学）
Pierre Talbot, Éric Monfroy, Charlotte Truchet
备注：
Paper presented at the 36th International Conference on Logic Programming (ICLP 2020), University Of Calabria, Rende (CS), Italy, September 2020, 17 pages. v2: Fix an example in Section 3.2 (improved closure)
发表信息：
Theory and Practice of Logic Programming 20 (2020) 848-863
Cooperation among constraint solvers is difficult because different solving paradigms have different theoretical foundations. Recent works have shown that abstract interpretation can provide a unifying theory for various constraint solvers. In particular, it relies on abstract domains which capture constraint languages as ordered structures. The key insight of this paper is viewing cooperation schemes as abstract domains combinations. We propose a modular framework in which solvers and cooperation schemes can be seamlessly added and combined. This differs from existing approaches such as SMT where the cooperation scheme is usually fixed (e.g., Nelson-Oppen). We contribute to two new cooperation schemes: (i) interval propagators completion that allows abstract domains to exchange bound constraints, and (ii) delayed product which exchanges over-approximations of constraints between two abstract domains. Moreover, the delayed product is based on delayed goal of logic programming, and it shows that abstract domains can also capture control aspects of constraint solving. Finally, to achieve modularity, we propose the shared product to combine abstract domains and cooperation schemes. Our approach has been fully implemented, and we provide various examples on the flexible job shop scheduling problem. Under consideration for acceptance in TPLP.
Strategy Synthesis in POMDPs via Game-Based Abstractions
Albert-Ludwigs-Universität Freiburg（弗莱堡大学）；Concept Engineering GmbH（Concept Engineering有限公司）；RWTH Aachen University（亚琛工业大学）；Radboud University（拉德堡德大学）；The University of Texas at Austin（德克萨斯大学奥斯汀分校）
