If you are new to the Discourse platform, which we are using for this forum, the Discourse New User Guide will show you the basics.

In short, text is formatted using Markdown (recommended), BBCode or HTML. The examples below will help you get started.

If you type

`**Bold**, _italic_, `print(str)` and a [link](http://igraph.org).`

it will format as

Bold,italic,`code`

and a link.

Program code can be delimited with triple backquotes. If you type

```` def sqr(x): y = x*x return y ````

it will format as

`def sqr(x): y = x*x return y`

In modern browsers, images can be pasted directly using `Ctrl`-`V` or `Command`-`V`. Here’s a visualization of Tietze’s graph:

This forum supports typing mathematics using LaTeX notation. The delimiters are `$`

for inline math and `$$`

(typed on a separate line) for display equations. If you type

`The equation $ax^2 + bx + c = 0$ has the solutions $$ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} $$`

it will format as

The equation ax^2 + bx + c = 0 has the solutions

x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}