The text search engine allows queries to be formed from arbitrary Boolean expressions containing the keywords AND, OR, and NOT, and grouped with parentheses. For example:

• information retrieval
• finds documents containing 'information' or 'retrieval'


• information or retrieval
• same as above


• information and retrieval
• finds documents containing both 'information' and 'retrieval'


• information not retrieval
• finds documents containing 'information' but not 'retrieval'


• (information not retrieval) and WAIS
• finds documents containing 'WAIS', plus 'information' but not 'retrieval'


• web*
• finds documents containing words starting with 'web'