一句话:证明按值调用 λ-演算编码进两个 π-演算子演算后,所诱导的项等价恰为含 η-等式的 Lassen 急切范式互模拟。
本文重新审视 Milner 将按值调用(call-by-value)λ-演算编码到 π-演算的经典工作。作者通过把编码精细地调整到两个 π-演算子演算——Internal π 与 Asynchronous Local π——使得编码在 λ-项上诱导的等价关系恰好与 Lassen 的急切范式互模拟(eager normal-form bisimilarity)重合,并且该对应关系可扩展以处理 η-等式。在 π-演算一侧,作者以上下文等价(contextual equivalence)和 barbed congruence 作为行为等价的标准,证明了编码是可靠且完备的:两个 λ-项在上述行为等价下不可区分,当且仅当它们在扩展后的急切范式互模拟下等价。文中进一步把结果从前述等价关系推广到相应的前序(preorder),从而给出按值调用函数式计算与并发进程行为之间更完整的语义对应图景。
We study Milner's encoding of the call-by-value λ-calculus into the π-calculus. We show that, by tuning the encoding to two subcalculi of the π-calculus (Internal π and Asynchronous Local π), the equivalence on λ-terms induced by the encoding coincides with Lassen's eager normal-form bisimilarity, extended to handle η-equality. As behavioural equivalence in the π-calculus we consider contextual equivalence and barbed congruence. We also extend the results to preorders.