9.4.4 Functional Names
Functions such as log and tan can't simply be typed in as
log or tan otherwise they will come out looking
like the variables l times
o times g (
)
or t times a times n
(
). Instead you should use
one of the commands listed in Table 9.5.
The functions denoted with can have limits by using
the subscript command _ or the superscript command ^[Sub- and
superscript positioning for operators].
In addition, the modulo commands listed in Table 9.6 are also available.
\arccos |
![]() |
\arcsin |
![]() |
\arctan |
![]() |
\arg |
![]() |
\cos |
![]() |
\cosh |
![]() |
\cot |
![]() |
\coth |
![]() |
\csc |
![]() |
\deg |
![]() |
\det |
![]() |
\dim |
![]() |
\exp |
![]() |
\gcd |
![]() |
\hom |
![]() |
\inf |
![]() |
\injlim |
![]() |
\ker |
![]() |
\lg |
![]() |
\lim |
![]() |
\liminf |
![]() |
\limsup |
![]() |
\ln |
![]() |
\log |
![]() |
\max |
![]() |
\min |
![]() |
\Pr |
![]() |
\projlim |
![]() |
\sec |
![]() |
\sin |
![]() |
\sinh |
![]() |
\sup |
![]() |
\tan |
![]() |
\tanh |
![]() |
\varinjlim |
![]() |
\varliminf |
![]() |
\varlimsup |
![]() |
\varprojlim |
![]() |
Command | Example Input | Example Output |
---|---|---|
\bmod |
$m \bmod n$ |
![]() |
\pmod {<maths>} |
$m \pmod{n}$ |
![]() |
\mod {<maths>} |
$m \mod{n}$ |
![]() |
\pod {<maths>} |
$m \pod{n}$ |
![]() |
Example (Trigonometric Functions):
This example uses the cos and sin functions and also the Greek letter theta.

Example (Limit):
The command \infty
is the
infinity symbol
, and the command
\to
displays an
arrow pointing to the right. Note the use of _ since the
limit is a subscript.

which now displays as:

Example (With Subscript):
This is another example of a functional name using a subscript:


9.4.4.1 Defining New Functional Operators
It may be that you want a function that isn't specified in Table 9.5. In this case, the amsmath provides the preamble only command
or its starred variant
[Defining a new log-like function in LaTeX]Both versions define a command called <cmd>, which must start
with a backslash, that typesets <operator name> as a function
name. The starred version is for function names that can take
limits (like \lim
and \min
described above).
Example (Operator Without Limits):
Suppose I want a function called card, which represents the
cardinality of a set
. First I need to define the new
operator command (which I'm going to call
\card
) in
the preamble:
This operator doesn't take any limits, so I have used the unstarred version.
Later in the document, I can use this new operator command:

\mathcal
is used as sets are
typically represented in a calligraphic font.
Example (Operator With Limits):
Suppose I now want a function called mode, which represents the mode of a set of numbers. First, I define the operator command in the preamble:
This operator needs to be able to have a subscript, so I have used the starred version.
Later in the document, I can use this new operator command:

This book is also available as A4 PDF or 12.8cm x 9.6cm PDF or paperback (ISBN 978-1-909440-00-5).