15. A device comprising: a memory; and a processor coupled to the memory and configured to: identify a semantic structure associated with a first term and a second term occurring in a document, where a plurality of rules are associated with the semantic structure, and where the semantic structure includes a list having a header and a plurality of items associated with the header; determine a semantically based distance relationship between the first term and the second term in the identified semantic structure; select one of the plurality of rules, as a selected rule, that corresponds to the distance relationship; where the processor is to select a first rule of the plurality of rules when the first term is located in one of the plurality of items and the second term is located in a different one of the plurality of items, where the processor is to select a second rule of the plurality of rules, different than the first rule, when the first term is located in one of the plurality of items and the second term is located in the same one of the plurality of items, and where the processor is to select a third rule of the plurality of rules, different than the first rule and the second rule, when the first term is located in the header and the second term is located in one of the plurality of items; determine, using a function based on the selected rule, a semantically based distance value between the first term and the second term, where the first term and the second term occur in a search query, and where the function differs based on whether the selected rule corresponds to the first rule, the second rule, or the third rule; rank the document for relevancy to the search query based on the semantically based distance value; and provide at least some of the ranks in response to the search query.
16. The device of claim 15 , where the processor is further configured to: locate implicitly defined semantic structures in the document; and use the implicitly defined semantic structures in determining the semantically based distance value.