(A intersect B) union (C intersect D)
<math xmlns="http://www.w3.org/1998/Math/MathML">
<apply>
<union/>
<apply>
<intersect/>
<ci>A</ci>
<ci>B</ci>
</apply>
<apply>
<intersect/>
<ci>C</ci>
<ci>D</ci>
</apply>
</apply>
</math>
Author: Design Science, Inc. (E. Cannon, E. Tabacman, R.Miner)