Rule of Idempotence/Disjunction/Formulation 1

Theorem
The disjunction operation is idempotent:
 * $p \dashv \vdash p \lor p$

This can be expressed as two separate theorems:

Technical Note
When invoking this version of the Rule of Idempotence in a tableau proof, use the Idempotence template:



where:
 * is the number of the line on the tableau proof where Rule of Idempotence 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 (or lines) of the tableau proof upon which this line directly depends
 * is the type of Rule of Idempotence whose link will be displayed in the Notes column: in this instance.