Browse Definitions:
Definition

logical implication

Logical implication is a type of relationship between two statements or sentences. The relation translates verbally into "logically implies" or "if/then" and is symbolized by a double-lined arrow pointing toward the right ( ). If A and B represent statements, then A B means "A implies B" or "If A, then B." The word "implies" is used in the strongest possible sense.

As an example of logical implication, suppose the sentences A and B are assigned as follows:

A = The sky is overcast.
B = The sun is not visible.

In this instance, A B is a true statement (assuming we are at the surface of the earth, below the cloud layer.) However, the statement B A is not necessarily true; it might be a clear night. Logical implication does not work both ways. However, the sense of logical implication is reversed if both statements are negated. That is,

(A B) (-B -A)

Using the above sentences as examples, we can say that if the sun is visible, then the sky is not overcast. This is always true. In fact, the two statements A B and -B -A are logically equivalent.

Also see logical equivalence and Mathematical Symbols .

This was last updated in September 2005

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

SearchSecurity

  • Web application firewall (WAF)

    A Web application firewall (WAF) is a firewall that monitors, filters or blocks traffic to and from a Web application. WAFs are ...

  • MD5

    The MD5 hashing algorithm is a one-way cryptographic function that accepts a message of any length as input and returns as output...

  • identity theft

    Identity theft, also known as identity fraud, is a crime in which an imposter obtains key pieces of personally identifiable ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • secondary storage

    Secondary storage is used to protect inactive data written from a primary storage array to a nonvolatile tier of disk, flash or ...

  • VRAM (video ram)

    VRAM (video RAM) is a reference to any type of random access memory (RAM) used to store image data for a computer display.

  • ZFS

    ZFS is a local file system and logical volume manager created by Sun Microsystems to control the placement, storage and retrieval...

SearchSolidStateStorage

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close