Periodic Reporting for period 1 - SyGaST (Synthesising Game Solving Techniques)
Période du rapport: 2021-07-01 au 2023-06-30
In particular, the research on the first task, that was the most speculative one, provided many negative results, that do not allow for an immediate publication but requires additional time. The transfer of algorithmic advances led to the development of new progress measures for solving parity games. A general approach has been accepted and will appear on "Computation and Automata" in the work "From Quasi-Dominions to Progress Measures", while a specific succinct approach has been published on "Frontiers in Computer Science" as "Smaller Progress Measures and Separating Automata for Parity Games". The composition of two techniques, one efficient in practice and the other with an efficient complexity bound, has been described in the journal "Priority Promotion with Parysian Flair" that is under submission. The proposed algorithm is the only efficient solver with quasi-polynomial guarantees, since the other known quasi-polynomial approaches tend to realize their worst-case behaviour. Advancements have been obtained also on mean-payoff games and discounted payoff games. For the first class of games, a refinement of the quasi-dominion approach has been submitted to a journal in the work "Solving Mean-Payoff Games via Quasi Dominions". For the second class of games, a novel technique will be presented at "GandALF 2023" in the work "An Objective Improvement Approach to Solving Discounted Payoff Games". To achieve the objectives of the last task, it has been started a collaboration with students to develop a quantitative framework that supports classes of games such as mean payoff in addition to parity games. While the set of parity games solvers will be imported from an older framework, the set of energy games solvers was incomplete, hence, in a first step of this collaboration the set of energy games has been completely implemented. In a second step, it has been started the development of the framework. The release of the first version as a tool paper has been planned within the year. In addition to these objectives, it has been conducted research on automata theory to investigate the good-for-games property. This study has been submitted in the work "Semantic Flowers for Good-for-Games and Deterministic Automata". Both this latter work and "Solving Mean-Payoff Games via Quasi Dominions" have passed the first review stage with positive comments and are waiting for the final comments.