Question 981762
<pre>
1. (T &#9679; K) v (C &#9679; E)
2. K &#64292; ~E
3. E &#64292; ~C             / T &#9679; K

4. ~E v ~C            3, material implication
5. ~(E &#9679; C)           4, DeMorgan
6. ~(C &#9679; E)           5, commutation
7. T &#9679; K            1,6, disjunctive syllogism

Edwin</pre>