mathmode spacing shorter than \quad?
A \quad
corresponds to a length of 1em
. In math mode, 1em=18mu
. Use \mkern<n>mu
, where <n>
can be either a positive or a negative number, to exert very fine control over spacing. Note: no curly braces around <n>mu
.
To space ahead by half a quad while in math mode, simply write \mkern9mu
.
Two macros that provide standard abbreviations for math-mode spacing directives are
\, -- \mkern3mu ("thinspace")
\! -- \mkern-3mu ("negative thinspace")
Is there a meaningful difference between a\hspace{0.5em}b
and a\mkern9mu b
? It usually will not make a difference for display-math material. However, it could make a difference for inline-math material. This is because TeX never discards explicit kerns (and \mkern
is a kern); in contrast, \hspace
could get discarded at the start and end of lines. Thus, if your document happens to have a longish inline math equation that's allowed to break across lines, using \mkern
or \hspace
inside the formula could make a difference. (If you wanted to allow potential line breaks while using mu-based spacing directives, don't use \mkern
; instead, use \mskip
instead.)
Citing the comment from @egreg:
" A quad is 1em; just use \hspace{0.5em} or \hspace{0.25em}. Indeed \quad means the same as \hspace{1em}. – egreg "
Thanks!
Therefore, might or not be helpful for some (for me it is convenient):
\newcommand{\Hquad}{\hspace{0.5em}}