How automatic linebreaking works in MathML?

Most MathML browsers will automatically add linebreaks before or after operators (<mo> tags) to break long formula into multiple lines with no indentation on subsequent lines.

For inline (default) mode, subsequent lines will be aligned to the left. For example:

<math><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow>
  <mi>∞</mi></munderover><msup><mi>i</mi><mn>2</mn></msup>
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>6</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>6</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>7</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>6</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>7</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>8</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo>
</math>

$\sum _{i=1}^{\infty }{i}^2=1^2+\dots =1^2+2^2+\dots =1^2+2^2+3^2+\dots =1^2+2^2+3^2+4^2+\dots =1^2+2^2+3^2+4^2+5^2+\dots =1^2+2^2+3^2+4^2+5^2+6^2+\dots =1^2+2^2+3^2+4^2+5^2+6^2+7^2+\dots =1^2+2^2+3^2+4^2+5^2+6^2+7^2+8^2+\dots$

For block mode, subsequent lines will be aligned to the center. For example:

<math display="block"><munderover><mo>∑</mo><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow>
  <mi>∞</mi></munderover><msup><mi>i</mi><mn>2</mn></msup>
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>6</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>6</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>7</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo> 
  <mo>=</mo><msup><mn>1</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>2</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>3</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>4</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>5</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>6</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>7</mn><mn>2</mn></msup><mo>+</mo>
    <msup><mn>8</mn><mn>2</mn></msup><mo>+</mo><mo>…</mo>
</math>

$$\sum _{i=1}^{\infty }{i}^2=1^2+\dots =1^2+2^2+\dots =1^2+2^2+3^2+\dots =1^2+2^2+3^2+4^2+\dots =1^2+2^2+3^2+4^2+5^2+\dots =1^2+2^2+3^2+4^2+5^2+6^2+\dots =1^2+2^2+3^2+4^2+5^2+6^2+7^2+\dots =1^2+2^2+3^2+4^2+5^2+6^2+7^2+8^2+\dots$$

⇒ Forced Linebreaking on "mo" Tags

⇐ Alignment, Indentation and Line Breaks

⇑ Alignment, Indentation and Line Breaks

⇑⇑ MathML (Mathematical Markup Language)