rec-emptyset1

empty set

W3C sample	WIRIS
[N/A]	$neq Z emptyset$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <csymbol cd="relation1">neq</csymbol>
    <csymbol cd="setname1">Z</csymbol>
    <csymbol cd="set1">emptyset</csymbol>
  </apply>
</math>

Author: MathML 2 Recommendation