Proof by Contradiction/Proof Rule/Tableau Form
Proof Rule
Let $\phi$ be a well-formed formula in a tableau proof.
The Proof by Contradiction is invoked for $\phi \vdash \bot$ in the following manner:
| Pool: | The pooled assumptions of $\bot$ | ||||||||
| Formula: | $\neg \phi$ | ||||||||
| Description: | Proof by Contradiction | ||||||||
| Depends on: | The series of lines from where the assumption $\phi$ was made to where $\bot$ was deduced | ||||||||
| Discharged Assumptions: | The assumption $\phi$ is discharged | ||||||||
| Abbreviation: | $\text{PBC}$ or $\neg \II$ |