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Daniel I. Scully

A Beginner's Guide to MathML

Sub-scripts & Super-scripts

Sub/Super-scripts are used in MathML not just for powers or indices, they are also used for limits.

Sub-scripts

Sub-Scripts are denoted with the <msub> tag. It accepts exactly 2 child elements, the first is the 'base', the second is the sub-script.

  1. <msub>
  2. <mi>x</mi>
  3. <mi>i</mi>
  4. </msub>
x i

As usual, you can use grouping elements, such as <mrow>, to group multiple tags so that there are only two child elements within the <msub>.

Super-scripts

The <msup> behaves in exactly the same way as for sub-scripts.

  1. <msup>
  2. <mi>e</mi>
  3. <mrow>
  4. <mi>x</mi>
  5. <mo>+</mo>
  6. <mn>2</mn>
  7. </mrow>
  8. </msup>
e x + 2

Sub-script Super-script pair

For the frequently encountered case when you need both sub and super-scripts we can use the <msubsup> tag:

  1. <msubsup>
  2. <mi>x</mi>
  3. <mi>2</mi>
  4. <mn>i</mn>
  5. </msubsup>
x 2 i

Note that this is different to nesting sub/super scripts:

  1. <msup>
  2. <msub>
  3. <mi>x</mi>
  4. <mn>i</mn>
  5. </msub>
  6. <mn>2</mn>
  7. </msup>
x i 2

Integration

  1. <msubsup>
  2. <mo>&Integral;</mo>
  3. <mn>0</mn>
  4. <mn>1</mn>
  5. </msubsup>
  6. <mi>x</mi>
  7. <mrow>
  8. <mo>&DifferentialD;</mo>
  9. <mi>x</mi>
  10. </mrow>
∫ 0 1 x ⅆ x

Under and Over Scripts

Exaclty like the sub and super scripts, we can place things above and below using three similar tags: <munder>, <mover> and <munderover>

  1. <munder>
  2. <mi>x</mi>
  3. <mo>⏟</mo>
  4. </munder>
  5. <mo>+</mo>
  6. <mover>
  7. <mi>y</mi>
  8. <mo>^</mo>
  9. </mover>
x ⏟ + y ^
  1. <munderover>
  2. <mi>&Sum;</mi>
  3. <mrow>
  4. <mi>x</mi>
  5. <mo>=</mo>
  6. <mn>0</mn>
  7. </mrow>
  8. <mi>n</mi>
  9. </munderover>
  10. <mrow>
  11. <mn>2</mn> <mi>x</mi>
  12. <mo>+</mo>
  13. <mn>1</mn>
  14. </mrow>
∑ x = 0 n 2 x + 1

As you can see from this second example, this is a suitable way to write summations.