# Latex and gitbook

## Quantum computing

### Brackets

```
\left\langle \frac{1}{2} \middle| 1 \right\rangle
```

$$\left\langle \frac{1}{2} \middle| 1 \right\rangle$$&#x20;

### Diagrams

```
\begin{matrix}
  && \Bbb Q(\sqrt{2},i) & \\
  &\huge\diagup & \huge| & \huge\diagdown \\
  \Bbb Q(\sqrt{2}) & & \Bbb Q(i\sqrt{2})&  & \Bbb Q(i)\\
  &\huge\diagdown & \huge| & \huge\diagup \\
  &&\Bbb Q
\end{matrix}
```

$$\begin{matrix}   && \Bbb Q(\sqrt{2},i) & \   &\huge\diagup & \huge| & \huge\diagdown \   \Bbb Q(\sqrt{2}) & & \Bbb Q(i\sqrt{2})&  & \Bbb Q(i)\   &\huge\diagdown & \huge| & \huge\diagup \   &&\Bbb Q \end{matrix}$$&#x20;

## Mathematics

### Fractions and brackets

```
\left( \begin{array}{cc} 2\tau & 7\phi-frac5{12} \\
3\psi & \frac{\pi}8 \end{array} \right)
\left( \begin{array}{c} x \\ y \end{array} \right)
\mbox{~and~} \left[ \begin{array}{cc|r}
3 & 4 & 5 \\ 1 & 3 & 729 \end{array} \right]
```

$$\left( \begin{array}{cc} 2\tau & 7\phi-frac5{12} \ 3\psi & \frac{\pi}8 \end{array} \right) \left( \begin{array}{c} x \ y \end{array} \right) \mbox{~~and~~} \left\[ \begin{array}{cc|r} 3 & 4 & 5 \ 1 & 3 & 729 \end{array} \right]$$&#x20;

### Function definition

```
f(z) = \left\{ \begin{array}{rcl}
\overline{\overline{z^2}+\cos z} & \mbox{for}
& |z|<3 \\ 0 & \mbox{for} & 3\leq|z|\leq5 \\
\sin\overline{z} & \mbox{for} & |z|>5
\end{array}\right.
```

$$f(z) = \left{ \begin{array}{rcl} \overline{\overline{z^2}+\cos z} & \mbox{for} & |z|<3 \ 0 & \mbox{for} & 3\leq|z|\leq5 \ \sin\overline{z} & \mbox{for} & |z|>5 \end{array}\right.$$&#x20;

### Equations align

```
\eqalign{
(a+b)^2 &= (a+b)(a+b) \\
        &= a^2 + ab + ba + b^2 \\
        &= a^2 + 2ab + b^2
}
```

$$\eqalign{ (a+b)^2 &= (a+b)(a+b) \         &= a^2 + ab + ba + b^2 \         &= a^2 + 2ab + b^2 }$$&#x20;

### Hat

```
\hat\imath

\hat\jmath	

\hat ab

\hat{ab}
```

$$\hat\imath \  \hat\jmath	\  \hat ab \ \hat{ab}$$&#x20;

### Matrices

#### Type 1

```

\begin{matrix}
\hline
x_{11} & x_{12} \\
x_{21} & x_{22} \strut \\
\hdashline
x_{31} & x_{32} \strut
\end{matrix}
```

$$\begin{matrix} \hline x\_{11} & x\_{12} \ x\_{21} & x\_{22} \strut \ \hdashline x\_{31} & x\_{32} \strut \end{matrix}$$&#x20;

#### Type 2

```
A = \pmatrix{
a_{11} & a_{12} & \ldots & a_{1n} \cr
a_{21} & a_{22} & \ldots & a_{2n} \cr
\vdots & \vdots & \ddots & \vdots \cr
a_{m1} & a_{m2} & \ldots & a_{mn} \cr
}
```

$$A = \pmatrix{ a\_{11} & a\_{12} & \ldots & a\_{1n} \cr a\_{21} & a\_{22} & \ldots & a\_{2n} \cr \vdots & \vdots & \ddots & \vdots \cr a\_{m1} & a\_{m2} & \ldots & a\_{mn} \cr }$$&#x20;

### Limits

```
\sum_{k=1}^n a_k
```

$$\sum\_{k=1}^n a\_k$$&#x20;

### References

A complete list is available at <https://www.onemathematicalcat.org/MathJaxDocumentation/TeXSyntax.htm>
