The Nature of MathMLprev up next58
Two types of tags: presentation & semantic; (a + b)2 
<msup> 
  <mfenced> 
    <mrow> 
      <mi>a</mi> 
      <mo>+</mo> 
      <mi>b</mi> 
    </mrow> 
  </mfenced> 
  <mn>2</mn> 
</msup>
 
<apply> 
  <power/> 
  <apply> 
    <plus/> 
    <ci>a</ci> 
    <ci>b</ci> 
  </apply> 
  <cn>2</cn> 
</apply>

m-math, c-content, o-operator, i-identifier, n-number