IBU News (Germany) Edition 0.9.9

IB search is built around the concept of set. The result of each search is a "result set". These may be combined.

The basic set element is the set of the relevant records to a single word or phrase. Query expressions can be build using multiple terms and combined together by operators to form a more complex query.

If "SetA" is the set of search A and "SetB" is the set of Search-B then:

• The union of SetA and SetB is the set of "Search-A OR Search-B".
• The intersection of SetA and SetB is the set of "Search-A AND Search-B".
• The complement of SetA is the set of all records in the index not contained in SetA. That's NOT SetA

The product of these operators is also a set and one may combine them with other sets using the operators. Operators that act on two sets are called "binary". Those that act on a single set are called "unary".

IB provides a very rich collection of very powerful set operators: [Binary operators] [Unary operators]