Definition

A definition is a statement of the meaning of a term (a word, phrase, or other set of symbols). Definitions can be classified into two large categories, intensional definitions (which try to give the essence of a term) and extensional definitions (which list every single object that a term describes). A term may have many different senses and multiple meanings, and thus require multiple definitions.

In mathematics, a definition is used to give a precise meaning to a new term, instead of describing a pre-existing term. Definitions and axioms are the basis on which all of mathematics is constructed.

Intensional definitions vs extensional definitions

An Intensional definition, also called a connotative definition, specifies the necessary and sufficient conditions for a thing being a member of a specific set. Any definition that attempts to set out the essence of something, such as that by genus and differentia, is an intensional definition.

An extensional definition, also called a denotative definition, of a concept or term specifies its extension. It is a list naming every object that is a member of a specific set.

Mos Def

Yasiin Bey (/jæˈsiːn ˈbeɪ/; born Dante Terrell Smith Bey; December 11, 1973), better known by his former stage name Mos Def (/ˈmoʊs ˈdɛf/), is an American hip hop recording artist, actor, comedian, and activist from Brooklyn, New York City, New York. Best known for his music, Bey embarked on his hip hop career in 1994, alongside his siblings in the short-lived rap group Urban Thermo Dynamics (UTD), after which he appeared on albums by Da Bush Babees and De La Soul. He subsequently formed the trio Black Star, alongside fellow Brooklyn-based rapper Talib Kweli, and Cincinnati producer Hi-Tek and released their eponymous debut album in 1998. He was a major force in late-1990s underground hip hop while under Rawkus Records. In 1999, Bey released his solo debut, Black on Both Sides, under Rawkus and Priority Records. His debut was followed by The New Danger (2004), True Magic (2006) and The Ecstatic (2009).

Prior to his career in music, Bey first entered public life as a child actor, having played roles in television movies, sitcoms, and theater, some of which were under the name Dante Beze. At the age of 14, he appeared in the TV movie God Bless the Child, which aired on ABC in 1988. He played the oldest child in the 1990 family sitcom You Take the Kids, shortly before it was cancelled. In 1995, he played the character "Dante" in The Cosby Mysteries. Since the early 2000s, Bey has been well known for his roles in films such as Something the Lord Made, Next Day Air, The Hitchhiker's Guide to the Galaxy, 16 Blocks, Be Kind Rewind, The Italian Job, Bamboozled and Brown Sugar, as well as for his portrayal of Brother Sam in the Showtime drama series Dexter. He is also known as the host of Def Poetry Jam, which aired on HBO between 2002 and 2007.

Talib Kweli

Talib Kweli Greene (born October 3, 1975) is an American hip hop recording artist, entrepreneur, and social activist. He is the son of professional educators. In 2011, Kweli founded Javotti Media, which is self-defined as "a platform for independent thinkers and doers. " Kweli earned recognition early on through his work with fellow Brooklyn artist, Yasiin Bey, formerly known as Mos Def, when they formed the group Black Star. Kweli's career continued with solo success including collaborations with famed producers Kanye West, Just Blaze, and Pharrell Williams. Kweli is known to support artists on the rise, such as J. Cole, Jay Electronica, Kendrick Lamar, and NIKO IS.

Early life

Born in Brooklyn, New York, Kweli grew up in a household in Park Slope. His mother, Brenda Greene, is an English professor at Medgar Evers College of the City University of New York and his father an administrator at Adelphi University. His younger brother, Jamal Greene, is a professor of Constitutional Law at Columbia Law School, a graduate of Yale Law School, and former clerk to Justice John Paul Stevens on the Supreme Court. As a youth, he was drawn to Afrocentric rappers, such as De La Soul and other members of the Native Tongues Posse whom he had met in high school. Kweli was a student at Cheshire Academy, a boarding school in Connecticut. He was previously a student at Brooklyn Technical High School before being academically dismissed. He later studied experimental theater at New York University.

Secret society

A secret society is a club or organization whose activities, events, and inner functioning are concealed from non-members. The society may or may not attempt to conceal its existence. The term usually excludes covert groups, such as intelligence agencies or guerrilla insurgencies, that hide their activities and memberships but maintain a public presence. The exact qualifications for labeling a group as a secret society are disputed, but definitions generally rely on the degree to which the organization insists on secrecy, and might involve the retention and transmission of secret knowledge, denial of membership or knowledge of the group, the creation of personal bonds between members of the organization, and the use of secret rites or rituals which solidify members of the group.

Anthropologically and historically, secret societies are deeply interlinked with the concept of the Männerbund, the all-male "warrior-band" or "warrior-society" of pre-modern cultures (see H. Schurtz, Alterklassen und Männerbünde, Berlin, 1902; A. Van Gennep, The Rites of Passage, Chicago, 1960).

San Francisco Bay Area

The San Francisco Bay Area is a populous region surrounding the San Francisco and San Pablo estuaries in Northern California. The region encompasses the major cities and metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas. The Bay Area's nine counties are Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and Sonoma. Home to approximately 7.44 million people, the nine-county Bay Area contains many cities, towns, airports, and associated regional, state, and national parks, connected by a network of roads, highways, railroads, bridges, tunnels and commuter rail. The combined statistical area of the region is the second-largest in California (after the Greater Los Angeles area), the fifth-largest in the United States, and the 43rd-largest urban area in the world.

The United States Office of Management and Budget (OMB) does not use the nine-county definition of the San Francisco Bay Area. The OMB has designated a more extensive 12-county Combined Statistical Area (CSA) titled the San Jose-San Francisco-Oakland, CA Combined Statistical Area which also includes the three counties of San Joaquin, Santa Cruz, and San Benito that do not border San Francisco Bay, but are economically tied to the nine counties that do.