— With the advent of Model-Driven Engineering (MDE) several model transformation approaches and languages have been developed in the last 5 years. Most of these existing approaches are metamodel-based with metamodels representing abstract syntax of the corresponding modeling language and also a data structure for storing models. However, this implementation specific focus makes it difficult for users of modeling languages to develop model transformations, because metamodels do not necessarily define all language concepts explicitly which are available for notation purposes. Therefore, we propose a by-example approach for defining inter-model mappings representing semantic correspondences between concrete domain models which is more user-friendly then directly specifying model transformation rules or mappings based on ract syntax. The inter-model mappings between domain models can be used to generate the model transformation rules, by-example, taking into account the already defi...