# RETRO's Markdown Syntax

I use a variation of Markdown for writing documentation and
when commenting code written in RETRO. The syntax is
described below.

## Basic Syntax

### Headings

Headings start with one or more number (`#`) signs. The
number of number signs should correspond to the heading
level.

    # Heading 1
    ## Heading 2
    ### Heading 3
    #### Heading 4

My Markdown does not support the alternate underline
format for headings.

### Paragraphs & Line Breaks

To create paragraphs, use a blank line to separate one or
more lines of text.

Do not add spaces or tabs at the start of a paragraph as
this may cause the Markdown tools to interpret the line
improperly.

Line breaks are entered at the end of each line.

### Emphasis

#### Bold

To make text bold, surround it with asterisks.

    The *bold* word.

#### Italic

To make text italic, surround it with front slashes.

    The /italic words/.

#### Underline

To underline text, surround it with underscores.

    Underline _some text_.

### Horizontal Rules

Horizontal rules can be inserted by starting a line with a
sequence of four or more dashes (`-`) or four or more alternating
dash and plus (`-+-+`) characters.

    ----

## Lists

Lists start with a `-` or `*`, followed by a space, then the item
text. Additionally, nested lists starting with two spaces before
the list marker can be used.

    - this is a list item
    - so is this

      - this will be indented
      - likewise

    - back to the standard level

## Code

### Code Blocks

Code blocks start and end with ~~~ on a line by themselves.

    Sum the values.

    ~~~
    { #10 #20 #13 #4 #22 } #0 [ + ] a:reduce
    ~~~

You can also denote code by starting the line with four spaces.

        This line will be treated as code.

### Test Blocks

Unit testing blocks start and end with ``` on a line by
themselves.

    ```
    { #10 #20 #13 #4 #22 } #0 [ + ] a:reduce
    ```

### Inline Code

To mark a sequence as inline code, surround it with backticks.

    For instance, look at the value in `Compiler` to see if
    the colon compiler is active.

## Escaping

You can preceed a character with a backslash (\\) to have it
not be processed as a Markdown element.