# Symbols:C

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## centi-

$\mathrm c$

The Système Internationale d'Unités metric scaling prefix denoting $10^{\, -2 }$.

Its $\LaTeX$ code is \mathrm {c} .

### Sources

$\mathrm C$ or $\mathrm c$

The hexadecimal digit $12$.

Its $\LaTeX$ code is \mathrm C  or \mathrm c.

## Roman Numerals

$\mathrm C$ or $\mathrm c$

The Roman numeral for $100$.

Its $\LaTeX$ code is \mathrm C  or \mathrm c.

## The Set of Complex Numbers

$\C$

The set of complex numbers.

The $\LaTeX$ code for $\C$ is \C  or \mathbb C or \Bbb C.

## The Set of Non-Zero Complex Numbers

$\C_{\ne 0}$
$\C_{\ne 0} = \C \setminus \left\{{0}\right\}$

The $\LaTeX$ code for $\C_{\ne 0}$ is \C_{\ne 0}  or \mathbb C_{\ne 0} or \Bbb C_{\ne 0}.

### Deprecated

$\C^*$
$\C^* = \C \setminus \left\{{0}\right\}$

The $\LaTeX$ code for $\C^*$ is \C^*  or \mathbb C^* or \Bbb C^*.

## Relative Complement

$\complement_S \left({T}\right)$ or $\mathcal C_S \left({T}\right)$

Let $S$ be a set, and let $T \subseteq S$, that is: let $T$ be a subset of $S$.

Then the set difference $S \setminus T$ can be written $\relcomp S T$, and is called the relative complement of $T$ in $S$, or the complement of $T$ relative to $S$.

Thus:

$\relcomp S T = \set {x \in S : x \notin T}$

The $\LaTeX$ code for $\complement_S \left({T}\right)$ is \complement_S \left({T}\right) .

The $\LaTeX$ code for $\mathcal C_S \left({T}\right)$ is \mathcal C_S \left({T}\right) .

## Set Complement

$\complement \left ({S}\right)$ or $\mathcal C \left ({S}\right)$

The set complement (or, when the context is established, just complement) of a set $S$ in a universe $\mathbb U$ is defined as:

$\map \complement S = \relcomp {\mathbb U} S = \mathbb U \setminus S$

See the definition of Relative Complement for the definition of $\relcomp {\mathbb U} S$.

The $\LaTeX$ code for $\complement \left ({S}\right)$ is \complement \left ({S}\right) .

The $\LaTeX$ code for $\mathcal C \left ({S}\right)$ is \mathcal C \left ({S}\right) .