Question 996085
<table border=1><tr><th>Number</th><th>Statement</th><th>Lines Used</th><th>Reason</th></tr><tr><td>1</td><td>(E -&gt; T) &amp; (T -&gt; O)</td><td></td><td></td></tr><tr><td>2</td><td>~O v E</td><td></td><td></td></tr><tr><td>:.</td><td>O &lt;--&gt; T</td><td></td><td></td></tr><tr><td>3</td><td>E -&gt; T</td><td>1</td><td>Simp</td></tr><tr><td>4</td><td>(T -&gt; O) &amp; (E -&gt; T)</td><td>1</td><td>Comm</td></tr><tr><td>5</td><td>T -&gt; O</td><td>4</td><td>Simp</td></tr><tr><td>6</td><td>~~O -&gt; E</td><td>2</td><td>MI</td></tr><tr><td>7</td><td>O -&gt; E</td><td>6</td><td>DN</td></tr><tr><td>8</td><td>O -&gt; T</td><td>7,3</td><td>HS</td></tr><tr><td>9</td><td>(O -&gt; T) &amp; (T -&gt; O)</td><td>8,5</td><td>Conj</td></tr><tr><td>10</td><td>O &lt;--&gt; T</td><td>9</td><td>ME</td></tr></table>

Acronyms/Abbreviations used
Simp = Simplification
Comm = Commutation
MI = Material Implication
ME = Material Equivalence
Conj = Conjunction
HS = Hypothetical Syllogism