Given a Markov decision process (MDP) $M$ and a formula $\Phi$, the strategy synthesis problem asks if there exists a strategy $\sigma$ s.t. the resulting Markov chain $M[\sigma]$ satisfies $\Phi$. This problem is known to be undecidable for the probabilistic temporal logic PCTL. We study a class of formulae that can be seen as a fragment of PCTL where a local, bounded horizon property is enforced all along an execution. Moreover, we allow for linear expressions in the probabilistic inequalities. This logic is at the frontier of decidability, depending on the type of strategies considered. In particular, strategy synthesis is decidable when strategies are deterministic while the general problem is undecidable.
翻译:考虑到Markov决策程序(MDP)$M美元和公式$Phi$,战略综合问题询问是否存在一项战略($\sigma$ s.t),由此产生的Markov链($M[\sgma]$x$x$\Phi$)满足了美元。众所周知,对于概率性时间逻辑PCTL来说,这个问题是无法消化的。我们研究了一组公式,这些公式可以被视为PCTL的碎片,在这种公式中,一个局部的、封闭的地平线属性随执行而执行。此外,我们允许在概率不平等中出现线性表达。这一逻辑处于可变性的前沿,取决于所考虑的战略类型。特别是,当战略具有确定性,而一般问题不可变现时,战略综合是可以分化的。