Principle of Non-Contradiction/Proof Rule/Technical Note

Theorem
When invoking the Principle of Non-Contradiction in a tableau proof, use the NonContradiction template:



or:

where:
 * is the number of the line on the tableau proof where the Principle of Non-Contradiction is to be invoked
 * is the pool of assumptions (comma-separated list)
 * is the first of the two lines of the tableau proof upon which this line directly depends
 * is the second of the two lines of the tableau proof upon which this line directly depends
 * is the (optional) comment that is to be displayed in the Notes column.