A Case Study on Evaluating Encodings Between Process Calculi
This paper systematically evaluates the quality of encodings between process calculi, specifically addressing the fidelity of two classical translations—from synchronous to asynchronous π-calculus—namely the Honda–Tokoro and Boudol encodings—under various behavioral equivalences. Method: We conduct a dual-dimensional verification within a unified formal framework, integrating Gorla’s five criteria for valid encodings with a hierarchy of semantic equivalences: trace equivalence, failure simulation, observational equivalence, and strong/weak bisimulation. Contribution/Results: Our analysis reveals that the Honda–Tokoro encoding satisfies only the weakest criterion—trace equivalence—whereas the Boudol encoding preserves the strictly stronger failure simulation equivalence, demonstrating significantly higher behavioral fidelity. This work establishes the first empirical benchmark for assessing encoding quality in process calculi and provides a reusable, principled methodology grounded in both syntactic validity criteria and semantic strength.