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propositional logic, Boolean algebra, Heyting algebra: is false when A is true and B is false but true otherwise. may mean the same as (the symbol may also indicate the domain and codomain of a function; see table of mathematical symbols).
A law of Boolean algebra is an identity such as x ∨ (y ∨ z) = (x ∨ y) ∨ z between two Boolean terms, where a Boolean term is defined as an expression built up from variables and the constants 0 and 1 using the operations ∧, ∨, and ¬. The concept can be extended to terms involving other Boolean operations such as ⊕, →, and ≡ ...
Other search engines may require that either the symbol & [7] or + [5] be added as a prefix before the keyword. These search engines use the "OR" Boolean expression as a default search setting. [5] Those search engines with a default "AND" expression can still do an "OR" search by using the | symbol inbetween keywords. [7]
A Boolean value is either true or false. A Boolean expression may be composed of a combination of the Boolean constants True/False or Yes/No, Boolean-typed variables, Boolean-valued operators, and Boolean-valued functions. [1] Boolean expressions correspond to propositional formulas in logic and are a special case of Boolean circuits. [2]
Regular expressions are used in search engines, in search and replace dialogs of word processors and text editors, in text processing utilities such as sed and AWK, and in lexical analysis. Regular expressions are supported in many programming languages.
Phrase search is one of many search operators that are standard in search engine technology, along with Boolean operators (AND, OR, and NOT), truncation and wildcard operators (commonly represented by the asterisk symbol), field code operators (which look for specific words in defined fields, such as the Author field in a periodical database ...
The (standard) Boolean model of information retrieval (BIR) [1] is a classical information retrieval (IR) model and, at the same time, the first and most-adopted one. [2] The BIR is based on Boolean logic and classical set theory in that both the documents to be searched and the user's query are conceived as sets of terms (a bag-of-words model ).
Boolean domain, a set consisting of exactly two elements whose interpretations include false and true; Boolean circuit, a mathematical model for digital logical circuits. Boolean expression, an expression in a programming language that produces a Boolean value when evaluated; Boolean function, a function that determines Boolean values or operators