Modus Ponendo Tollens/Variant/Formulation 1/Forward Implication

Theorem

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

Proof

 * align="right" | 5 ||
 * align="right" | 1, 2, 3
 * $\bot$
 * $\neg \mathcal E$
 * 4, 1
 * 4, 1