Alexander Vinson,  Marcos Nunes,  Carlos Heuser. 

XML's modelling flexibility allows the creation of well described models. On the other hand, the same flexibility helped the appearance of some modelling technics that add descriptions and do not enhance semantically the model. That way, when functions compare such elements they can have their precision decreased. In this context, this articles objetive is to present pre-processing functions for XML documents that, by simplifying the the documents representation, enhances the comparisons functions results.

http://ccet.ucs.br/erbd2007/artigos/26141.pdf

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