Markdown Syntax
===============

This document describes the syntax of texts containing
markdown elements. The markdown syntax is intended to simplify
the writing of texts whose source is readable and can be easily formatted,
e.g., as part of a web document.
It is a subset of the
[original markdown syntax](http://en.wikipedia.org/wiki/Markdown)
(basically, only internal links and pictures are missing)
supported by the
[Curry](http://curry-language.org/) library
`Text.Markdown` provided by the package
[markdown](https://www.informatik.uni-kiel.de/~curry/cpm/markdown.html).

Paragraphs and Basic Formatting
-------------------------------

Paragraphs are separated by at least one line which is empty
or does contain only blanks.

Inside a paragraph, one can _emphasize_ text or
also **strongly emphasize** text. This is done by wrapping it
with one or two \_ or \* characters:

    _emphasize_
    *emphasize*
    __strong__
    **strong**

Furthermore, one can also mark `program code` text by
backtick quotes (`\``):

    The function `fib` computes Fibonacci numbers.

Web links can be put in angle brackets, like in the
link <http://www.google.com>:

    <http://www.google.com>

If one wants to put a link under a text,
one can put the text in square brackets directly followed by the
link in round brackets, as in
[Google](http://www.google.com):

    [Google](http://www.google.com)

If one wants to put a character that has a specific meaning
in the syntax of Markdown,
like \* or \_, in the output document, it should be escaped with a
backslash, i.e., a backslash followed by a special character in the
source text is translated into the given character
(this also holds for program code, see below).
For instance, the input text

    \\_word\\_

produces the output "\_word\_".
The following backslash escapes are recognized:

    \\   backslash
    \`   backtick
    \*   asterisk
    \_   underscore
    \{\}  curly braces
    \[\]  square brackets
    \<\>  angle brackets
    \(\)  parentheses
    \#   hash symbol
    \+   plus symbol
    \-   minus symbol (dash)
    \.   dot
    \    blank
    \!   exclamation mark

Lists and Block Formatting
--------------------------

An **unordered list** (i.e., without numbering)
is introduced by putting a star in front of the list elements
(where the star can be preceded by blanks). The individual
list elements must contain the same indentation, as in

    \* First list element
      with two lines
    
    * Next list element.
    
      It contains two paragraphs.
    
    * Final list element.

This is formatted as follows:    

 * First list element
   with two lines

 * Next list element.

   It contains two paragraphs.

 * Final list element.

Instead of a star, one can also put dashes or plus to mark
unordered list items. Furthermore, one could nest lists.
Thus, the input text

    \- Color:
      + Yellow
      + Read
      + Blue
    \- BW:
      + Black
      + White

is formatted as

 - Color:
   + Yellow
   + Read
   + Blue
 - BW:
   + Black
   + White

Similarly, **ordered lists** (i.e., with numbering each item)
are introduced by a number followed by a dot and at least one blank.
All following lines belonging to the same numbered item
must have the same indent as the first line.
The actual value of the number is not important. Thus, the input

    1\. First element
    
    99. Second
        element

is formatted as

 1. First element

 99. Second
     element

A quotation block is marked by putting a right angle followed
by a blank in front of each line:

    > This is
    > a quotation.

It will be formatted as a quote element:

> This is
> a quotation.

A block containing **program code** starts with a blank line and is
marked by intending each input line by _at least four spaces_ where
all following lines must have at least the same indentation as the
first non-blank character of the first line:

    \    f x y = let z = (x,y)
    \             in (z,z)

The indentation is removed in the output:

    f x y = let z = (x,y)
             in (z,z)

To visualize the structure of a document, one can also put a line
containing only blanks and at least three dashes (stars would also work)
in the source text:

    \-------------------------------------------------

This is formatted as a horizontal line:

-------------------------------------------------

Headers
-------

The are two forms to mark headers.
In the first form, one can "underline" the main header
in the source text by equal signs
and the second-level header by dashes:

    First-level header
    ==================

    Second-level header
    -------------------

Alternatively (and for more levels), one can prefix the
header line by up to six hash characters, where the number of
characters corresponds to the header level (where level 1 is the
main header):

    # Main header
    
    ## Level 2 header
    
    ### Level 3
    
    #### Level 4
    
    ##### Level 5
    
    ###### Level 6
    
***********************************************************************