The undecidability of basic decision problems for general FIFO machines such as reachability and unboundedness is well-known. In this paper, we provide an underapproximation for the general model by considering only runs that are input-bounded (i.e.\ the sequence of messages sent through a particular channel belongs to a given bounded language). We prove, by reducing this model to a counter machine with restricted zero tests, that the rational-reachability problem (and by extension, control-state reachability, unboundedness, deadlock, etc.) is decidable. This class of machines subsumes input-letter-bounded machines, flat machines, linear FIFO nets, and monogeneous machines, for which some of these problems were already shown to be decidable. These theoretical results can form the foundations to build a tool to verify general FIFO machines based on the analysis of input-bounded machines.

中文翻译：

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在FIFO机器中可以确定有限的可达性问题

通用FIFO机器的基本决策问题（如可达性和无边界性）的不确定性是众所周知的。在本文中，我们通过仅考虑输入受限的运行（即，通过特定通道发送的消息序列属于给定的受限语言）来为通用模型提供近似值。通过将这个模型简化为带有受限零测试的计数器机器，我们证明了有理可及性问题（以及扩展，控制状态可及性，无界性，死锁等）是可以判定的。这类机器包含有输入字母限制的机器，平面机器，线性FIFO网络和异构机器，对于这些机器，其中的一些问题已被证明是可以判定的。