Uniform winning strategies for the synchronization games on subclasses of finite automata
Henning Fernau, Carolina Haase, Stefan Hoffmann, Mikhail Volkov
TL;DR
The paper analyzes synchronization games on DFAs through the lens of algebraic structure, focusing on the DS pseudovariety of finite monoids. It proves that every synchronizing DS-automaton admits a uniform winning strategy, with the proof leveraging a semilattice decomposition of the transition monoid into semigroups nilpotent over their kernels. It also shows that DS is the largest pseudovariety enjoying this uniform strategy property, by exhibiting a counterexample outside DS, and connects the findings to known automata families (definite, commutative, weakly acyclic). The work further discusses decidability, bounds on strategy length, and robustness under a modified adversarial rule, and outlines open questions for efficiency and broader generalizations.
Abstract
The pseudovariety $\mathbf{DS}$ consists of all finite monoids whose regular $D$-classes form subsemigroups. We exhibit a uniform winning strategy for Synchronizer in the synchronization game on every synchronizing automaton whose transition monoid lies in $\mathbf{DS}$, and we prove that $\mathbf{DS}$ is the largest pseudovariety with this property.
