Symbols:Symbolic Logic/Biconditional

Biconditional

$\iff$

Biconditional.

A binary operation on two propositions.

$P \iff Q$ means $P$ is true if and only if $Q$ is true.

The $\LaTeX$ code for \(P \iff Q\) is P \iff Q .

Deprecated Symbols

Double Arrow

$\leftrightarrow$

Biconditional.

An alternative to $P \iff Q$.

The $\LaTeX$ code for \(P \leftrightarrow Q\) is P \leftrightarrow Q .

Identity

$\equiv$

Biconditional.

An alternative to $P \equiv Q$.

The $\LaTeX$ code for \(P \equiv Q\) is P \equiv Q .

Sources

• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): Appendix: Table $7$: Common signs and symbols: equivalence
• 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): Appendix $14$: Symbols