Structure-conforming XML document transformation based on graph homomorphism

We propose a principled method to specify XML document transformation so that the outcome of a transformation can be ensured to conform to certain structural constraints as required by the target XML document type. We view XML document types as graphs, and model transformations as relations between the two graphs. Starting from this abstraction, we use and extend graph homomorphism as a formalism for the specifications of transformations between XML document types. A specification can then be checked to ensure whether results from the transformation will always be structure-conforming.