<part xmlns="http://docbook.org/ns/docbook"
      xmlns:xlink="http://www.w3.org/1999/xlink"
      xmlns:xi="http://www.w3.org/2001/XInclude"
      version="5.0"
      xml:id='chap-writing-nix-expressions'>

<title>Writing Nix Expressions</title>

<partintro>
<para>This chapter shows you how to write Nix expressions, which 
instruct Nix how to build packages.  It starts with a
simple example (a Nix expression for GNU Hello), and then moves
on to a more in-depth look at the Nix expression language.</para>

<note><para>This chapter is mostly about the Nix expression language.
For more extensive information on adding packages to the Nix Packages
collection (such as functions in the standard environment and coding
conventions), please consult <link
xlink:href="http://nixos.org/nixpkgs/manual/">its
manual</link>.</para></note>
</partintro>

<xi:include href="simple-expression.xml" />
<xi:include href="expression-language.xml" />

</part>