19.  Size and Font Changes

      By default, equations are set in 10-point type (the same size as this guide), with standard mathematical conventions to determine what characters are in roman and what in italic. Although EQN makes a valiant attempt to use esthetically pleasing sizes and fonts, it is not perfect. To change sizes and fonts, use size n and roman, italic, bold and fat. Like sub and sup, size and font changes affect only the thing that follows them, and revert to the normal situation at the end of it. Thus bold x y
is

[equation]

and size 14 bold x = y +
size 14 {alpha + beta}
gives

[equation]

As always, you can use braces if you want to affect something more complicated than a single letter. For example, you can change the size of an entire equation by size 12 { ... }

      Legal sizes which may follow size are 6, 7, 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 28, 36. You can also change the size by a given amount; for example, you can say size~+2 to make the size two points bigger, or size~-3 to make it three points smaller. This has the advantage that you don't have to know what the current size is.

      If you are using fonts other than roman, italic and bold, you can say font X where X is a one character TROFF name or number for the font. Since EQN is tuned for roman, italic and bold, other fonts may not give quite as good an appearance.

      The fat operation takes the current font and widens it by overstriking: fat grad is [equation] and fat {x sub i} is [equation].

      If an entire document is to be in a non-standard size or font, it is a severe nuisance to have to write out a size and font change for each equation. Accordingly, you can set a ``global'' size or font which thereafter affects all equations. At the beginning of any equation, you might say, for instance, ^EQ
gsize 16
gfont R
...
^EN
to set the size to 16 and the font to roman thereafter. In place of R, you can use any of the TROFF font names. The size after gsize can be a relative change with + or -.

      Generally, gsize and gfont will appear at the beginning of a document but they can also appear thoughout a document: the global font and size can be changed as often as needed. For example, in a footnote*** you will typically want the size of equations to match the size of the footnote text, which is two points smaller than the main text. Don't forget to reset the global size at the end of the footnote.