Yaacov Y. Weiss

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When a query is evaluated under bag semantics, each answer is returned as many times as it has derivations. Bag semantics has long been recognized as important, especially when aggregation functions will be applied to query results. This paper is the first to focus on bag semantics for XPath queries. In particular, the problem of bag-equivalence of a large(More)
This article investigates the problem of learning tree patterns that return nodes with a given set of labels, from example graphs provided by the user. Example graphs are annotated by the user as being either <i>positive</i> or <i>negative</i>. The goal is then to determine whether there exists a tree pattern returning tuples of nodes with the given labels(More)
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