Peirce's Law/Formulation 1

Theorem

 * $\left({p \implies q}\right) \implies p \vdash p$

Proof

 * align="right" | 2 ||
 * align="right" |
 * $p \lor \lnot p$
 * LEM
 * (None)
 * (None)


 * align="right" | 4 ||
 * align="right" | 3
 * $p \implies q$
 * Sequent Introduction
 * 3
 * False Statement Implies Every Statement
 * align="right" | 5 ||
 * align="right" | 1, 3
 * $p$
 * $\implies \mathcal E$
 * 1, 4
 * $\implies \mathcal E$
 * 1, 4