Math font attributes

The selection of fonts within math mode is quite different to that of text fonts. Some math fonts are selected explicitly by one-argument commands such as \mathsf{max} or \mathbf{vec}; such fonts are called math alphabets. These math alphabet commands affect only the font used for letters and symbols of type \mathalpha (see Section 3.6); other symbols within the argument will be left unchanged. The predefined math alphabets are:

Alphabet	Description	Example
\mathnormal	default	abcXYZ
\mathrm	roman	abcXYZ
\mathbf	bold roman	abcXYZ
\mathsf	sans serif	$\mathsf{abcXYZ}$
\mathit	text italic	$\mathit{abcXYZ}$
\mathtt	typewriter	abcXYZ
\mathcal	calligraphic	$\mathcal{XYZ}$

Other math fonts are selected implicitly by TEX for symbols, with commands such as \oplus (producing $\oplus$) or with straight characters like >> or +. Fonts containing such math symbols are called math symbol fonts. The predefined math symbol fonts are:

Symbol font	Description	Example
operators	symbols from \mathrm	$[\;+\;]$
letters	symbols from \mathnormal	$<<\star>>$
symbols	most LATEX symbols	$\leq*\geq$
largesymbols	large symbols	$\sum\prod\int$

Some math fonts are both math alphabets and math symbol fonts, for example \mathrm and operators are the same font, and \mathnormal and letters are the same font. Math fonts in L^ATEX have the same five attributes as text fonts: encoding, family, series, shape and size. However, there are no commands that allow the attributes to be individually changed. Instead, the conversion from math fonts to these five attributes is controlled by the math version. For example, the normal math version maps:

Math font		External font
Alphabets	Symbol fonts	Attributes
\mathnormal	letters	OML	cmm	m	it
\mathrm	operators	OT1	cmr	m	n
\mathcal	symbols	OMS	cmsy	m	n
	largesymbols	OMX	cmex	m	n
\mathbf		OT1	cmr	bx	n
\mathsf		OT1	cmss	m	n
\mathit		OT1	cmr	m	it
\mathtt		OT1	cmtt	m	n

The bold math version is similar except that it contains bold fonts. The command \boldmath selects the bold math version. Math versions can only be changed outside of math mode. The two predefined math versions are:

normal	the default math version
bold	the bold math version

Packages may define new math alphabets, math symbol fonts, and math versions. This section describes the commands for writing such packages.