Introduction

This is the first paragraph of the introduction chapter.

First

This is the first subsection. Please, admire the gloriousnes of Figure \ref{seagull_image}.

This is the second subsection.

Please, check [First] subsection.

Please, check this subsection.

Please, check Table \ref{example_table}.

Table: This is an example table.\label{example_table}

Formula example: \mu = \sum_{i=0}^{N} \frac{x_i}{N}

Now, full size:

\mu = \sum_{i=0}^{N} \frac{x_i}{N}

And a code sample:

def hello_world
  puts "hello world!"
end

hello_world

Check these unicode characters: ǽß¢ð€đŋμ