Biconditional elimination allows one to infer a conditional from a biconditional: if ( A ↔ B ) is true, then one may infer one direction of the biconditional, either ( A → B ) or ( B → A ).
For example, if it's true that I'm breathing if and only if I'm alive, then it's true that if I'm breathing, I'm alive; likewise, it's true that if I'm alive, I'm breathing.
Formally:
( A ↔ B )
∴ ( A → B )
also
( A ↔ B )
∴ ( B → A )
