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>.
Let's build a simple mathematical equation a + b = 5 using MathML notation.
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>
Syntax
<math xmlns = "http://www.w3.org/1998/Math/MathML"> <mrow> <mi>a</mi> <mo>+</mo> <mi>b</mi> </mrow> </math>
Output
<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>
Output