![]() īoolean expressions correspond to propositional formulas in logic and are a special case of Boolean circuits. A Boolean expression may be composed of a combination of the Boolean constants true or false, Boolean-typed variables, Boolean-valued operators, and Boolean-valued functions. In computer science, a Boolean expression is an expression used in programming languages that produces a Boolean value when evaluated. You cannot use the AND operator in queries that include the NEAR operator.Expression in a computer program that produces either "true" or "false" when evaluated NEAR/0 means words joined by the operator should be adjacent. TS = (Germany NEAR/10 (monetary NEAR/0 union)) The two words must be within five words of each other If you leave out the quotation marks, the system returns an error: Search Error: Invalid use of NEAR operator.īeverage NEAR/5 bottle finds records containing both beverage and bottle. Valid Search ExampleĪtomistic simulations of a solid/liquid interface: a combined force field and first principles approach to the structure and dynamics of acetonitrile "near" an anatase For example, these searches are equivalent:Īlways enclose NEAR in quotation marks ( " " ) when it appears in the title of a source item such as a journal, book, proceeding, or other type of work. If you use NEAR without /x, the system will find records where the terms joined by NEAR are within 15 words of each other. Replace the x with a number to specify the maximum number of words that separate the terms. Use NEAR/x to find records where the terms joined by the operator are within a specified number of words of each other. ![]() Note: For DOI, PMID and Accession number fields we use OR as an implicit operator. TITLE: ( 말 AND 폐렴) returns records where 말 and 폐렴 both appear in a title.TITLE: ( 말 폐렴) returns records where 말 and 폐렴 are adjacent in a title.TITLE: (海洋 AND 地震) returns records where 海洋 and 地震 both appear in a title.TITLE: (海洋 地震) returns records where 海洋 and 地震 are adjacent in a title.Implicit AND in Chinese and Korean-Languageīy contrast, implied-AND logic does not apply to Chinese and Korean-language queries. For example, typing rainbow trout fish farm in an All Fields search is equivalent to typing rainbow AND trout AND fish AND farm both queries render the same number of results. Web of Science search uses an implicit AND operator in most fields when you enter two or more adjacent terms. You can also enclose the entire query in quotation marks. When you search for organization names that include a Boolean operator (AND, NOT, NEAR, and SAME), always enclose the operator in quotation marks ( " " ). Implied AND does not apply to Chinese-language search queries.įinds records containing any of the terms separated by the operatorīeverage OR bottle finds records containing beverage or bottle or both search termsĮxcludes records containing certain words from your searchīeverage NOT bottle finds records containing beverage but excludes records containing bottle Rainbow trout fish farm is equivalent to rainbow AND trout AND fish AND farm Our product uses an implicit AND operator when you enter two or more adjacent terms in most fields. Finds records containing all terms separated by the operator
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