Thereom for about [[Conditional|Implication]] and [[Logical Negation]] with [[Proposition|Propositions]]. $\huge\begin{align} \ba{\neg q \wedge \pa{p\to q}} \to \neg p \end{align} $ $\huge\begin{split} \neg q \\ p \to q \\ \hline \therefore \neg p \end{split} $