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In logic and related fields such as mathematics and philosophy, if and only if (shortened iff) is a biconditional logical connective between statements.

In that it is biconditional, the connective can be likened to the standard material conditional ("only if," equal to "if ... then") combined with its reverse ("if"); hence the name. The result is that the truth of either one of the connected statements requires the truth of the other, i.e., either both statements are true, or both are false. It is controversial whether the connective thus defined is properly rendered by the English "if and only if", with its pre-existing meaning. Of course, there is nothing to stop us stipulating that we may read this connective as "only if and if", although this may lead to confusion.

In writing, phrases commonly used, with debatable propriety, as alternatives to P "if and only if" Q include Q is necessary and sufficient for P, P is equivalent (or materially equivalent) to Q (compare material implication), P precisely if Q, P precisely (or exactly) when Q, P exactly in case Q, and P just in case Q. Many authors regard "iff" as unsuitable in formal writing; others use it freely.^{[citation needed]}

French Montana (born November 9, 1984) is an American rapper and singer of Moroccan and Somali descent. He is the founder and CEO of Cocaine City Records, and in 2012, signed a joint venture recording deal with Maybach Music Group and Bad Boy Records. He is known for his frequent collaborations with Max B, and more recently with Rick Ross and with his group Coke Boys.

French Montana was born Karim Kharbouch in 1984 in Rabat, Morocco, where he lived for the first 13 years of his life. Growing up in Rabat, he was consumed by playing soccer and rapping, describing them as his two favorite childhood hobbies. In 1996, French emigrated with his parents and two younger brothers to the Bronx in New York City. His father left the family when French was 17, and so he began to provide for his mother and younger brothers.

In 2002, along with his friend Camz he created a series of street-flavoured DVD documentaries called 'Cocaine City' after drawing inspiration from the 'Smack' DVD series. Under the name Young French he used the DVDs as a means of showcasing his talent as an underground artist. To gain a broader fan base, French incorporated interviews with major artists, as well as some up and comers. The first edition in the series included Pee Wee Kirkland and Remy Ma alongside French himself among others. What started out as simply a medium for developing an audience quickly grew into one of the top-selling "street DVDs". The series ran for 8 years between 2002 and 2010, with a total of 14 editions being released.

David John "Dave" Matthews (born January 9, 1967) is a South African-American musician and actor, best known as the lead vocalist, songwriter, and guitarist for the Dave Matthews Band. He performs mainly with acoustic guitar and favors rhythm rather than solos in his playing.

David John Matthews was born in Johannesburg, South Africa, the third of four children of parents John and Valerie Matthews. At two years old, Matthews' family moved to Yorktown Heights in Westchester County, New York, where his father, a physicist, started working for IBM.

In 1974, the family moved to Cambridge, England, for a year before returning to New York, where his father died from lung cancer in 1977. Biographer Nevin Martell argues that Dave's father's death may be an impetus for his "carpe diem" lyrics. At some point while residing in New York, Matthews attended his first concert, when his mother took him to a performance by Pete Seeger. The family moved back to Johannesburg, South Africa, in 1977.

Upon Matthews' graduation from St Stithians College high school in 1985, he was faced with conscription into the South African military just as civil disobedience to the practice was becoming widespread. A Quaker (and consequently pacifist), Matthews left South Africa to avoid service.

Sarah Asher Tua Geronimo is a Filipino recording artist and actress. Geronimo started her official debut in show business after having won the Star for a Night singing competition. In 2003, after winning the contest, she released her first album entitled Popstar: A Dream Come True under Viva Records. It is considered as Geronimo's most successful album which sold more than 210,000 copies nationwide.

She is the first Filipino artist to receive a platinum award for a DVD copy of her concert The Other Side in 2005 and is currently the only artist who has a platinum record for 4 DVDs of her concert. Her fourth one was awarded with triple platinum status in December of 2010.

Moreover, Geronimo received from the Aliw Awards the "Best Female Major Concert" award for Record Breaker and the "Entertainer of the Year" award, making her the youngest artist to receive it in history.

Geronimo was crowned as the Philippines' Box-Office Queen in 2008 and 2009 for her movies, A Very Special Love and You Changed My Life.