Reverse Engineering Grammar Relationships

Many software languages (and programming languages, in particular) are described simultaneously by multiple grammars that are found in different software artifacts. For instance, one grammar may reside in a language specification; another grammar may be encoded in a parser specification; yet another grammar may be present in an XML schema for toolindependent data exchange. Ideally, one would want to reliably establish and continuously maintain that all co-existing (potentially embedded) grammars describe the same intended language. Without such guarantee, grammar inconsistencies may go unnoticed, and grammar-based software artifacts may get brittle. Some ad hoc or brute force methods exist to address this problem, but ultimately grammar consistency checking is an open software engineering problem without a satisfying best practice.