Logical Operators

Use logical operators to limit your search criteria in a number of ways. Table 7-1 describes some of these operators.

Table 1 Logical Operators

Operator	Symbol	Description	Example Expression
AND	&	Use to search for documents that contain at least one occurrence of each of the query terms. The returned score is the minimum of the operands.	'cats AND dogs' 'cats & dogs'
OR	|	Use to search for documents that contain at least one occurrence of any of the query terms. The returned score is the maximum of the operands.	'cats | dogs' 'cats OR dogs'
NOT	~	Use to search for documents that contain one query term and not another.	To obtain the documents that contain the term animals but not dogs, use the following expression: 'animals ~ dogs'
ACCUM	,	Use to search for documents that contain at least one occurrence of any of the query terms. The accumulate operator ranks documents according to the total term weight of a document.	The following query returns all documents that contain the terms dogs, cats, and puppies, giving the highest scores to the documents that contain all three terms: 'dogs, cats, puppies'
EQUIV	=	Use to specify an acceptable substitution for a word in a query.	The following example returns all documents that contain either the phrase alsatians are big dogs or German shepherds are big dogs: 'German shepherds=alsatians are big dogs'