Definition:Finished Branch of Propositional Tableau

Definition
Let $T$ be a propositional tableau.

Let $\Gamma$ be a branch of $T$.

Then $\Gamma$ is finished iff:
 * $(1): \quad \Gamma$ is not contradictory
 * $(2): \quad$ Every non-basic WFF on $\Gamma$ is used at some node of $\Gamma$.

That is, $\Gamma$ is finished iff the set $\Delta$ of WFFs of propositional logic which occur along $\Gamma$ is a finished set‎.