iff

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conjunction \ˈif-ən(d)-ˈōn-lē-ˌif; ˈif, sometimes read with a prolonged f\

Definition of iff

  1. :  if and only if two figures are congruent iff one can be placed over the other so that they coincide —used in logic and mathematics

Origin and Etymology of iff

alteration of 1if


First Known Use: 1955


IFF

abbreviation

Definition of IFF

  1. identification, friend or foe

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