# Reductio ad Absurdum/Proof Rule/Tableau Form

Let $\phi$ be a propositional formula in a tableau proof.
The Reductio ad Absurdum is invoked for $\neg \phi \vdash \bot$ in the following manner:
 Pool: The pooled assumptions of $\bot$ Formula: $\phi$ Description: Reductio ad Absurdum Depends on: The series of lines from where the assumption $\neg \phi$ was made to where $\bot$ was deduced Discharged Assumptions: The assumption $\neg \phi$ is discharged Abbreviation: $\text{RAA}$