24. The media of claim 23 , wherein the plurality of computer-readable instructions, when executed, are further operable to cause one or more computing devices to: receive a new search query, the new search query comprising one or more of the words; search through the sixth BDD; for each of the paths that leads to the 1 terminal node, if the search query on the path equals the new search query, then include all web pages on the path in a search result for the new search query; and return the search result in response to the new search query.
23. The media of claim 22 , wherein: the sixth BDD comprises: a binary 0 terminal node; a binary 1 terminal node; and a plurality of paths, each path comprising a plurality of decision nodes and leading to either the 0 terminal node or the 1 terminal node, and for each of the paths that leads to the 1 terminal node, a web page represented by first one or more of the decision nodes on the path is included in a search result for a search query represented by second one or more of the decision nodes on the path.