union3

A union empty set eq A

W3C sample	WIRIS
[N/A]	$eq union A φ A$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <csymbol cd="relation1">eq</csymbol>
    <apply>
      <csymbol cd="set1">union</csymbol>
      <ci>A</ci>
      <ci>φ</ci>
    </apply>
    <ci>A</ci>
  </apply>
</math>

Author: Design Science, Inc. (E. Cannon, E. Tabacman, R.Miner)