Types and concept analysis for legacy systems

We combine type inference and concept analysis in order to gain insight into legacy software systems. Type inference for COBOL yields the types for variables and program parameters. These types are used to perform mathematical concept analysis on legacy systems. We have developed ConceptRefinery, a tool for interactively manipulating concepts. We show how this tool facilitates experiments with concept analysis, and lets reengineers employ their knowledge of the legacy system to refine the results of concept analysis.