<p><b>Copyright information:</b></p><p>Taken from "A general strategy to determine the congruence between a hierarchical and a non-hierarchical classification"</p><p>http://www.biomedcentral.com/1471-2105/8/442</p><p>BMC Bioinformatics 2007;8():442-442.</p><p>Published online 15 Nov 2007</p><p>PMCID:PMC2213689.</p><p></p>nces while the one on the right serves to show more clearly the underlying topology