union2

(A intersect B) union (C intersect D)

W3C sample	WIRIS
	$A\cap B\cup C\cap D$

<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)