一句话:引入无穷字上 MSO 的直觉主义变体 SMSO,通过基于自动机的可实现性模型建立其与 Church 合成的可靠性与完备性。
Church 合成问题问是否存在有限状态流转换器满足给定的输入输出规约。对无穷字上的 MSO 规约,该问题理论上可用自动机与博弈算法求解。本文用 Curry-Howard 对应重新审视 Church 合成,引入 SMSO——无穷字上 MSO 的直觉主义变体。借助基于自动机的可实现性(realizability)模型,作者证明 SMSO 相对合成是可靠且完备的,从而将合成问题转化为证明与程序构造问题。
Church's synthesis problem asks whether there exists a finite-state stream transducer satisfying a given input-output specification. For specifications written in Monadic Second-Order Logic (MSO) over infinite words, Church's synthesis can theoretically be solved algorithmically using automata and games. We revisit Church's synthesis via the Curry-Howard correspondence by introducing SMSO, an intuitionistic variant of MSO over infinite words, which is shown to be sound and complete w.r.t. synthesis thanks to an automata-based realizability model.