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iff

iff

2 9.9
Two statements are true exactly in the same cases
  • subordinating conjunction
  • /ɪf/
  • Specialized
: si y solo si
  • A statement is considered true iff it can be proven through logical deductions.

Examples

  • Also, permissibility is usually defined in terms of oughts (one is permitted to A iff it is not the case that one ought not to A).

    Blog text (5)
  • A function f is continuous iff it is continuous at every point in its domain.

  • A set is closed under an operation iff applying the operation to members of the set always produces another member of the set.

Synonyms

biconditional
vsiff
  • Specialized
1 9.5

About two statements that are either both true or both false

is the abbreviated mathematical label used for that exact logical relation

Surface Forms

iff main

Etymology

Iff is a math short form made by writing if twice to mean 'if and only if'. It is used in logic and mathematics to show that two statements are true exactly when the other is true.