Reductio ad Absurdum/Variant 1

Theorem
If, by making an assumption $\neg p$, we can infer a contradiction as a consequence, then we may infer $p$:
 * $\neg p \implies \bot \vdash p$

Comment
It can be seen that this result depends on the rule of Double Negation Elimination.

As this depends on the Law of the Excluded Middle, it invalidates the Reductio Ad Absurdum from the intuitionist system.

Linguistic Note
Reductio ad absurdum is Latin for reduction to absurdity.