Consultation language
The system of text search allows to make consultations
in format of expressions arbitrary Boolean with the keywords AND, OR
and NOT, and contained among parenthesis.
For example
information recovery
it searches documents that contain ' information' or ' recovery'
information or recovery the same as above
information and recovery
it searches documents that contain so much ' information' and ' recovery'
information not recovery
it searches documents that contain ' information' but not ' recovery'
(information not recovery) and WAIS
it searches documents that contain ' WAIS' and ' information', but not '
recovery'
web *
it searches documents that contain words that begin with ' web'