# Biconditional Introduction

Jump to navigation Jump to search

## Proof Rule

The rule of biconditional introduction is a valid deduction sequent in propositional logic.

### Proof Rule

If we can conclude both $\phi \implies \psi$ and $\psi \implies \phi$, then we may infer $\phi \iff \psi$.

### Sequent Form

$p \implies q, q \implies p \vdash p \iff q$

## Also known as

Some sources refer to the Biconditional Introduction as the rule of Conditional-Biconditional.