Double Negation/Double Negation Elimination

Theorem
The rule of double negation elimination is a valid deduction sequent in propositional logic: If we can conclude $\neg \neg p$, then we may infer $p$.

It can be written:
 * $\displaystyle {\neg \neg p \over p} \neg \neg_e$

Variants
The following forms can be used as variants of this theorem:

Also see

 * Double Negation Elimination implies Law of Excluded Middle

Technical Note
When invoking Double Negation Elimination in a tableau proof, use the DoubleNegElimination template:



or:

where:
 * is the number of the line on the tableau proof where Double Negation Elimination is to be invoked
 * is the pool of assumptions (comma-separated list)
 * is the statement of logic that is to be displayed in the Formula column, without the  delimiters
 * is the line of the tableau proof upon which this line directly depends
 * is the (optional) comment that is to be displayed in the Notes column.