---
# System prepended metadata

title: Hello world!

---

# Hello world!

## Try some Python
```python=101
print(Hello world!)

def function(**keywords):
    print(keywords)
```
## I've heard someone told me
> An apple a day, keep doctors away.

## Try some math $y=ax+b$
$$
\ln x=\int\frac{dx}{x}
$$

$$
\mathbf{A}=\left[\begin{matrix} a & b\\ c & d \end{matrix}\right]
$$

## Try some music
```abc
X:1
T:Notes
M:C
L:1/4
K:C
C, D, E, F,|G, A, B, C|D E F G|A B c d|e f g a|b c' d' e'|f' g' a' b'|]
```


## Try flow chart
```flow
st=>start: Start:>http://www.google.com[blank]
e=>end:>http://www.google.com
op1=>operation: My Operation
sub1=>subroutine: My Subroutine
cond=>condition: Yes
or No?:>http://www.google.com
io=>inputoutput: catch something...
para=>parallel: parallel tasks

st->op1->cond
cond(yes)->io->e
cond(no)->para
para(path1, bottom)->sub1(right)->op1
para(path2, top)->op1
```