“…In these graphs, units of information (entities and relations in [MB97], sentences in [Mih05]) are interconnected to form a graph based either on collocation (indicative, for instance, of context [MB97]), or on sentence similarity (indicating for instance presumed semantic similarity [Mih05,ER04a]). Trees, which are actually a subconcept of graphs, like the dependency trees in [BM05], can be used as well to represent a sentence, given the output of a syntactic parser and a set of rules. The representation of structured relationships conveys information that has been utilized either for salience indication and selection of sentences, or for reformulation of a summary.…”