<p>IF &nbsp;<span class="math-editor mathquill-rendered-math"><var>A</var><span class="binary-operator">=</span><span class="non-leaf"><span class="scaled paren" style="transform: scale(1, 1.05);">{</span><span class="non-leaf">1,2,3</span><span class="scaled paren" style="transform: scale(1, 1.05);">}</span></span><var>B</var><span class="binary-operator">=</span><span class="non-leaf"><span class="scaled paren" style="transform: scale(1, 1.05);">{</span><span class="non-leaf">3,4,5</span><span class="scaled paren" style="transform: scale(1, 1.05);">}then<span style="font-family: Times New Roman, Symbola, serif;"><em> <var class="florin">&fnof;</var><span style="display: inline-block; width: 0;">&nbsp;</span><var>i</var><var>n</var><var>d</var> &nbsp;<var>A</var><span class="binary-operator">&cup;</span><var>B</var> ?</em></span></span></span></span></p>