When typesetting mathematics, LaTeX puts in spacing according to the
normal rules for mathematics texts. If you enter y=m x
then
LaTeX ignores the space and in the output the m is next to the x,
as y=mx.
But LaTeX’s rules occasionally need tweaking. For example, in an
integral the tradition is to put a small extra space between the
f(x)
and the dx
, here done with the \,
command:
\int_0^1 f(x)\,dx
LaTeX provides the commands that follow for use in math mode. Many
of these spacing definitions are expressed in terms of the math unit
mu. It is defined as 1/18em, where the em is taken from the
current math symbols family (see Units of length). Thus, a
\thickspace
is something like 5/18 times the width of
a ‘M’.
\;
¶Synonym: \thickspace
. Normally 5.0mu plus 5.0mu
. With
the amsmath
package, or as of the 2020-10-01 LaTeX release,
can be used in text mode as well as math mode; otherwise, in math mode
only.
\negthickspace
¶Normally -5.0mu plus 2.0mu minus 4.0mu
. With the amsmath
package, or as of the 2020-10-01 LaTeX release, can be used in text
mode as well as math mode; otherwise, in math mode only.
\:
¶\>
Synonym: \medspace
. Normally 4.0mu plus 2.0mu minus
4.0mu
. With the amsmath
package, or as of the 2020-10-01
LaTeX release, can be used in text mode as well as math mode; before
that, in math mode only.
\negmedspace
¶Normally -4.0mu plus 2.0mu minus 4.0mu
. With the amsmath
package, or as of the 2020-10-01 LaTeX release, can be used in text
mode as well as math mode; before that, in math mode only.
\,
¶Synonym: \thinspace
. Normally 3mu
, which is 1/6em.
Can be used in both math mode and text mode (see \thinspace
& \negthinspace
).
This space is widely used, for instance between the function and the
infinitesimal in an integral \int f(x)\,dx
and, if an author does
this, before punctuation in a displayed equation.
The antiderivative is \begin{equation} 3x^{-1/2}+3^{1/2}\,. \end{equation}
\!
¶Synonym: \negthinspace
. A negative thin space. Normally
-3mu
. With the amsmath
package, or as of the 2020-10-01
LaTeX release, can be used in text mode as well as math mode;
otherwise, the \!
command is math mode only but the
\negthinspace
command has always also worked in text mode
(see \thinspace
& \negthinspace
).
\quad
¶This is 18mu, that is, 1em. This is often used for space
surrounding equations or expressions, for instance for the space between
two equations inside a displaymath
environment. It is available
in both text and math mode.
\qquad
¶A length of 2 quads, that is, 36mu = 2em. It is available in both text and math mode.