Conjunction Equivalent to Negation of Implication of Negative/Formulation 1/Forward Implication

Theorem

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

Proof
{{ModusPonens|5|1, 2|\neg q|2|3| ... and demonstrate a contradiction {{Contradiction|7|1|\neg \left({p \implies \neg q}\right)|2|6}} {{EndTableau}} {{qed}}
 * align="right" | 6 ||
 * align="right" | 1, 2
 * $\bot$
 * $\neg \mathcal E$
 * 4, 5
 * 4, 5