Section: New Results

Behavioral properties of higher-order programs

In a series of results [28] , [27] , we have been able to cast to traditional denotational semantics the behavioral properties captured by Monadic Second Order Logic (MSOL) and weak MSOL. The main difficulty was to represent infinitary properties in finitary models. From a foundational point of view, these results exhibit once more the robustness of approaches based on recognizability to capture complex properties of programs. They also make salient the problem of program evaluation in finite models as a milestone towards effective model-checking of higher-order programs.