Reductio ad Absurdum/Proof Rule/Tableau Form

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Proof Rule

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:    $\text{RAA}$