Proof by Contradiction/Sequent Form

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The Proof by Contradiction can be symbolised by the sequent:

$\paren {p \vdash \bot} \vdash \neg p$


By the tableau method of natural deduction:

$\paren {p \vdash \bot} \vdash \neg p$
Line Pool Formula Rule Depends upon Notes
1 1 $p \vdash \bot$ Premise (None)
2 2 $p$ Assumption (None)
3 1 $\neg p$ Proof by Contradiction: $\neg \II$ 2 – 2 Assumption 2 has been discharged