---
tags:
  - Logic
  - propositional-logic
  - derivation-rules
---

Give that the biconditional means that if $P$ is the case, $Q$ is the case and if $Q$ is the case, $P$ must be the case, if we have $P \equiv Q$ and $P$, we can derive $Q$ and vice versa.

![biconditional-elim.png](../img/biconditional-elim.png)