- Biconditional introduction
In

mathematical logic ,**biconditional introduction**is therule of inference that, if B follows from A, and A follows from B, then Aif and only if B.For example, from the statements "if I'm breathing, then I'm alive" and "if I'm alive, then I'm breathing", it can be inferred that "I'm breathing if and only if I'm alive".

Formally, biconditional introduction is the rule schema

:$A\; o\; B\; ,$:$underline\{B\; o\; A\}$:$A\; leftrightarrow\; B$

**ee also***

Logical biconditional

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