Browse Definitions :
Definition

logical negation symbol

The logical negation symbol is used in Boolean algebra to indicate that the truth value of the statement that follows is reversed. The symbol resembles a dash with a 'tail' (¬). The arithmetic subtraction symbol (-) or tilde (~) are also used to indicate logical negation.

The simplest use of a negation symbol is with a single sentence. For example, if A represents the statement "The sky is blue," then ¬A represents the statement "The sky is not blue" or "It is not true that the sky is blue."

The negation symbol is often found within, or preceding, complex logical statements. In Boolean algebra, the plus sign (+) represents the logical inclusive OR, and the asterisk (*) represents the logical AND. Rules for use of the logical negation symbol become more complicated when the symbol appears in complex statements. For example, these pairs of statements are not equivalent for all A and for all B:

¬(A + B)
(¬A) + (¬B)

¬(A * B)
(¬A) * (¬B)

However, the following pairs of statements are logically equivalent for all A and for all B:

¬(A + B)
(¬A) * (¬B)

¬(A * B)
(¬A) + (¬B)

Also see Boolean algebra, and the Mathematical Symbols .

This was last updated in September 2005
SearchCompliance
  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

  • information governance

    Information governance is a holistic approach to managing corporate information by implementing processes, roles, controls and ...

  • enterprise document management (EDM)

    Enterprise document management (EDM) is a strategy for overseeing an organization's paper and electronic documents so they can be...

SearchSecurity
  • session key

    A session key is an encryption and decryption key that is randomly generated to ensure the security of a communications session ...

  • data breach

    A data breach is a cyber attack in which sensitive, confidential or otherwise protected data has been accessed and/or disclosed ...

  • multifactor authentication (MFA)

    Multifactor authentication (MFA) is a security technology that requires more than one method of authentication from independent ...

SearchHealthIT
SearchDisasterRecovery
  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

  • call tree

    A call tree is a layered hierarchical communication model that is used to notify specific individuals of an event and coordinate ...

  • Disaster Recovery as a Service (DRaaS)

    Disaster recovery as a service (DRaaS) is the replication and hosting of physical or virtual servers by a third party to provide ...

SearchStorage
  • cloud storage

    Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, ...

  • cloud testing

    Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software ...

  • storage virtualization

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage ...

Close