There are five basic elements of a MathML expression.

• <math> element − It is top or root level element and is used to encapsulate each instance of MathML instance. Every valid MathML expression should be wrapped in outer <math> tag. It can contain any number of child elements. One math element cannot contain another math element tag.

• <mrow> element − It is used to group any number of sub expressions in horizontal way.

• <mi> element − It is used to specify an identifier such as name of a variable, function or a constant etc. For example, <mi>PI</mi> .

• <mo> element − It is used to specify an operator like +, – etc. For example, <mo>+</mo>.

• <mn> element − It is used to specify a numerical literal like 3.14 etc. For example, <mn>3.14</mn>.

Example

Let”s build a simple mathematical equation a + b = 5 using MathML notation.

Step 1: Identification

Here a, b are variables. + is an operator and 5 is a number. We”ll enclose them as <mi>a</mi> , <mi>b</mi>, <mo>+</mo> and <mn>+</mn>

Step 2: Build Expression, a + b.

Syntax

<math xmlns = "http://www.w3.org/1998/Math/MathML">
   <mrow>  
      <mi>a</mi>  
      <mo>+</mo>  
      <mi>b</mi>  
   </mrow>
</math>

<math xmlns = "http://www.w3.org/1998/Math/MathML">
   <mrow> 
      <mrow>  
         <mi>a</mi>  
         <mo>+</mo>  
         <mi>b</mi>  
      </mrow>
      <mo>=</mo>  
      <mn>5</mn>  
   </mrow>
</math>