How to use the MathML Identifier Element: "mi"?

"mi" is the MathML Identifier Element that allows you to specify a symbolic name in a mathematical express.

The syntax for "mi" element is:

<mi mathvariant="normal" | "bold" | "italic" ...>name</mi>

Here are some guidelines on how to specify a symbolic name:

• Multiple characters are allowed.
• Unicode characters are allowed.
• XML entities are allowed.
• Spaces and numbers should not be used.
• Operators and symbols should not be used.

Here are some good examples of "mi" elements:

<math>
  <mrow>
    <mi>x</mi><mo>,</mo>
    <mi>sin</mi><mo>,</mo>
    <mi>radius</mi><mo>,</mo>
    <mi>pi</mi><mo>,</mo>
    <mi>δ</mi><mo>,</mo>
    <mi>&#x2026;</mi><mo>,</mo>
  </mrow>
</math>

The above MathML example represents:

$x,\sin ,\mathrm{radius},\mathrm{pi},\delta ,\dots ,$

Here are some bad examples of "mi" elements:

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mi>a2</mi><mo>,</mo>
    <mi>2a</mi><mo>,</mo>
    <mi> radius </mi><mo>,</mo>
    <mi>a-b</mi><mo>,</mo>
    <mi>x y</mi><mo>,</mo>
  </mrow>
</math>

The above MathML example represents:

$\mathrm{a2},\mathrm{2a},\mathrm{radius},\mathrm{a-b},\mathrm{x\; y},$

⇒ "mn" - MathML Number Element

⇐ Simple MathML Elements

⇑ Simple MathML Elements

⇑⇑ MathML (Mathematical Markup Language)