Degree of derivative test has wrong MathML

[MichaelClerx]

https://www.w3.org/TR/2001/REC-MathML2-20010221/chapter4.html#contm_opwithqual

<?xml version="1.0" encoding="UTF-8"?>
<!-- CellML Test Suite. https://github.com/MichaelClerx/cellml-validation -->
<!-- CellML 1.0, 5.5.2: A derivative's degree can't be true -->
<model name="boolean_derivatives_2"
       xmlns="http://www.cellml.org/cellml/1.0#"
       xmlns:cellml="http://www.cellml.org/cellml/1.0#">
  <component name="A">
    <variable name="time" units="dimensionless" initial_value="0" />
    <variable name="V" units="dimensionless" initial_value = "-0.08" />
    <math xmlns="http://www.w3.org/1998/Math/MathML">
      <apply>
        <eq/>
        <apply>
          <diff/>
          <bvar>
            <ci>time</ci>
          </bvar>
          <degree>
            <true />
          </degree>
          <ci>V</ci>
        </apply>
        <cn cellml:units="dimensionless">0.001</cn>
      </apply>
    </math>
  </component>
</model>

should be

<?xml version="1.0" encoding="UTF-8"?>
<!-- CellML Test Suite. https://github.com/MichaelClerx/cellml-validation -->
<!-- CellML 1.0, 5.5.2: A derivative's degree can't be true -->
<model name="boolean_derivatives_2"
       xmlns="http://www.cellml.org/cellml/1.0#"
       xmlns:cellml="http://www.cellml.org/cellml/1.0#">
  <component name="A">
    <variable name="time" units="dimensionless" initial_value="0" />
    <variable name="V" units="dimensionless" initial_value = "-0.08" />
    <math xmlns="http://www.w3.org/1998/Math/MathML">
      <apply>
        <eq/>
        <apply>
          <diff/>
          <bvar>
            <ci>time</ci>
            <degree>
              <true />
            </degree>
          </bvar>
          <ci>V</ci>
        </apply>
        <cn cellml:units="dimensionless">0.001</cn>
      </apply>
    </math>
  </component>
</model>