# MathML Basic Elements by Stephen Bucaro

MathML (Mathematical Markup Language), similar to HTML which is used to encode the structure and content of a webapge, is an XML dialect for encoding mathematical expressions on a webapge. MathML most basic elements are <mn>, <mi> and <mo>.

mn Use this element to specify a numeric literal.

mi Use this element to specify an identifier, for example the name of a variable.

mo Use this element to specify an operator, for example +, -, =. Brackets are also considered operators.

Examples:

$y+4=5$
```[itex]
<mi>y</mi>
<mo>+</mo>
<mn>4</mn>
<mo>=</mo>
<mn>5</mn>
[/itex]
```

Most basic math expressions can be rendered with these three elements.

$2x-14+3\left(x+2\right)=-4$
```[itex]
<mn>2</mn>
<mi>x</mi>
<mo>-</mo>
<mn>14</mn>
<mo>+</mo>

<mn>3</mn>
<mo>(</mo>
<mi>x</mi>
<mo>+</mo>
<mn>2</mn>
<mo>)</mo>

<mo>=</mo>
<mn>-4</mn>
[/itex]
```

Note that the mo operator is used to place parentheses.

$6\left(2x+2-4\left(4x-2\right)\right)$
```[itex]
<mn>6</mn>
<mo>(</mo>
<mn>2</mn>
<mi>x</mi>
<mo>+</mo>
<mn>2</mn>
<mo>-</mo>
<mn>4</mn>
<mo>(</mo>

<mn>4</mn>
<mi>x</mi>
<mo>-</mo>
<mn>2</mn>
<mo>)</mo>
<mo>)</mo>
[/itex]
```

The example above uses nested parentheses, a set of parentheses inside another set. Of course, to evaluate nested parentheses, start by evaluating the inner set of and then work your way outward.