# Extension:Math/Displaystyle

This is a demopage.

It is related to the Math extension of Mediawiki.

## Attribute:display

editWe introduce the new attribute display with the two options "inline" and "block".

### Inline

editIf the the value of the display attribute is inline the render will render math in inline mode, i.e. there will be no new paragraph for the equation and the operators will be rendered consuming only little vertical space.

#### Example

editThe sum $\sum}_{i=0}^{\mathrm{\infty}}{2}^{-i$ converges to 2.

The next line-width is not disturbed by large operators.

The code for the math example reads:

`<math display="inline">\sum_{i=0}^\infty 2^{-i}</math>`

#### Technical implementation

editTechnically it will add the command *\textstyle* to the user input before the tex command is passed to the renderer. The result will be displayed without further alterations by outputting the image or MathMLelement to the page.

#### Remark

editThe convention https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style_(mathematics)#Using_HTML is really annoying. I'd prefer to use inline math for that, since it helps to differentiate between math and other elements.

### Block

editIn block-style the equation is rendered in its own paragraph and the operators are rendered consuming less horizontal space.

#### Example

editThe equation $$\text{geometric series:}\phantom{\rule{1em}{0ex}}{\displaystyle \sum _{i=0}^{\mathrm{\infty}}}{2}^{-i}=2$$ is used in a joke about mathematicians entering a bar and ordering beer.

It was entered as

`<math display="block">\text{geometric series:}\quad\sum_{i=0}^\infty 2^{-i}=2 </math>`

#### Technical implementation

editTechnically it will add the command *\displaystyle* will be added to the user input, if the user input does not contain the string *\displaystyle* or *\align* before the tex command is passed to the renderer. The result will be displayed in a new paragraph.
Therefore the style of the MathImage is altered i.e. the style attribute "display:block;margin:auto" is added.
For MathML it is ensured that display=inline is replaced by display block which produces a new paragraph

#### Discussion

editFréderic Wang would prefer that displaystyle is always added in depended of the fact if \displaystlye is already in the equation. He remarks that it has to be checked if that works if the equation starts with \begin.

### Not specified

editIf nothing is specified the current behavior is preserved. That means all equation are rendered in display style but not using a new paragraph.

#### Example

editThe sum $\displaystyle \sum _{i=0}^{\mathrm{\infty}}}{2}^{-i$ converges to 2.

The next line-width is disturbed by large operators.

The code for the math example reads:

`<math>\sum_{i=0}^\infty 2^{-i}</math>`

The equation

- $\text{geometric series:}\phantom{\rule{1em}{0ex}}{\displaystyle \sum _{i=0}^{\mathrm{\infty}}}{2}^{-i}=2$

is used in a joke about mathematicians entering a bar and ordering beer.

It was entered as

`:<math>\text{geometric series:}\quad \sum_{i=0}^\infty 2^{-i}=2 </math>`