mel- model extractor language for extracting facts from models.

There is a large body of research on extracting models from code-related artifacts to enable model-based analyses of large software systems. However, engineers do not always have access to the entire code base of a system: some components may be procured from third-party suppliers based on a Model specification or their code may be generated automatically from Models. This paper introduces mel --- a model extraction language and interpreter for extracting "facts" from Models represented in XMI; these facts can be combined with facts extracted from other system components to form a lightweight model of an entire software system. We provide preliminary evidence that mel is sufficient to specify fact extraction from Models that have very different XMI representations. We also show that it can be easier to use mel to create a fact extractor for a particular Model representation, than to develop a specialized fact extractor for the Model from scratch.