The code for mutating (strengthening) invariants to obtain Classifying Terms has been implemented within the USE tool.
To be able to use it, the folder src has to be merged with the src folder of the USE tool source code (version 5.0.1). The USE tool can be downloaded from: https://sourceforge.net/projects/useocl/
In order to use our tool, the program CTGen.java has to be executed. It receives two command line parameters: the name of the input ".use" file and the name of the output text file where the CTs will be stored.
The folder examples contains examples that illustrate how constraint mutation is applied to the generation of Classifying Terms for obtaining diverse instantiations for a conceptual schema.