Adding semantics to an expression

<semantics>
  <apply>
  <divide/>
    <cn>123</cn>
    <cn>456</cn>
  </apply>
  <annotation encoding="Mathematica">N[123/456, 39]</annotation>
  <annotation encoding="Maple">evalf(123/456, 39);</annotation>
  <annotation-xml encoding="OpenMath">
    <OMA xmlns="http://www.openmath.org/OpenMath">
	  <OMS cd="arith1" name="divide"/>
	  <OMI>123</OMI>
	  <OMI>456</OMI>
    </OMA>
  </annotation-xml>
</semantics>