We present the model transformation language of the VIATRA2 framework, which provides
a rule- and pattern-based transformation language for manipulating graph models by
combining graph transformation and abstract state machines into a single specification
paradigm. This language offers advanced constructs for querying (e.g. recursive graph
patterns) and manipulating models (e.g. generic transformation and meta-transformation
rules) in unidirectional model transformations frequently used in formal model analysis
to carry out powerful abstractions. (c) 2007 Elsevier B.V. All rights reserved.