Modus Tollendo Tollens/Proof Rule/Technical Note

Technical Note on
When invoking  in a tableau proof, use the ModusTollens template:



or:

where:
 * is the number of the line on the tableau proof where 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 first of the two lines of the tableau proof upon which this line directly depends, the one in the form $\phi \implies \psi$
 * is the second of the two lines of the tableau proof upon which this line directly depends, the one in the form $\phi$
 * is the (optional) comment that is to be displayed in the Notes column.