# Hypertext Help with LaTeX

Math fonts and styles

## Math styles

The following applies to both LaTeX 2.09 and LaTeX2e.
There are four styles used in typesetting math
formulas which affect the size and certain formatting parameters
(notably the placement of sub and superscripts on
variable size symbols).

`\textstyle` - default in the running text and in
array environment
`\displaystyle` - default for displayed equations
`\scriptstyle` - default for first-level sub and superscripts
`\scriptscriptstyle` - default for higher-level sub and superscripts

All four of these may be used in math mode as
declarations to **force** the
type size and formatting to a style other than what would normally be used.
For example, to get a superscript that is the same size as the running text:

`$e^{\textstyle -E/kT}`$

As another example, the limits on a summation symbol are normally placed
below and above the symbol in `display` style and in normal sub and
superscript position in `textstyle`. One could **force**
the below/above placement in running text by using:

`\displaystyle $\sum_{n=0}^\infty x_n$`

although it should be noted that this might cause LaTeX to leave extra
space between the text lines which might not be desirable.
## LaTeX 2.09 fonts

The regular type style declarations can be
used in math mode.
They affect only letters (including upper case Greek
letters) but not symbols
(or lower case Greek letters). Two additional style
declarations which can be used
**only** in math mode are
The former is math italic style; it spaces letters as if they were words,
however, not as if they were each separate math symbols.
The latter produces upper case calligraphic letters.
## LaTeX2e math fonts

The following declarations change the style
only of letters, numbers, and uppercase Greek.
`\mathit` - same as `\mit` in 2.09 (see above)
`\mathrm` - Roman
`\mathbf` - Bold face
`\mathsf` - San Serif
`\mathtt` - Typewriter style
`\mathcal` - Calligraphic

All of these produce spacing appropriate for text; they do not interpret each
letter as a separate math symbol.
The `\boldmath` declaration causes
everything (including symbols) in a formula to be in a bold font.
Note that this differs somewhat from the same declaration in 2.09 which
did not affect some symbols.

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Revised: Sheldon Green, 2 Jun 1995.