1 files changed, 29 insertions, 35 deletions
diff --git a/nixos/doc/manual/development/assertions.xml b/nixos/doc/manual/development/assertions.xml
index d3434e1f112e..17c38ffcc717 100644
--- a/nixos/doc/manual/development/assertions.xml
+++ b/nixos/doc/manual/development/assertions.xml
@@ -3,30 +3,29 @@
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-assertions">
+ <title>Warnings and Assertions</title>
 
-<title>Warnings and Assertions</title>
+ <para>
+  When configuration problems are detectable in a module, it is a good idea to
+  write an assertion or warning. Doing so provides clear feedback to the user
+  and prevents errors after the build.
+ </para>
 
-<para>
-  When configuration problems are detectable in a module, it is a good
-  idea to write an assertion or warning. Doing so provides clear
-  feedback to the user and prevents errors after the build.
-</para>
-
-<para>
+ <para>
   Although Nix has the <literal>abort</literal> and
-  <literal>builtins.trace</literal> <link xlink:href="https://nixos.org/nix/manual/#ssec-builtins">functions</link> to perform such tasks,
-  they are not ideally suited for NixOS modules. Instead of these
-  functions, you can declare your warnings and assertions using the
+  <literal>builtins.trace</literal>
+  <link xlink:href="https://nixos.org/nix/manual/#ssec-builtins">functions</link>
+  to perform such tasks, they are not ideally suited for NixOS modules. Instead
+  of these functions, you can declare your warnings and assertions using the
   NixOS module system.
-</para>
-
-<section>
+ </para>
 
-<title>Warnings</title>
+ <section>
+  <title>Warnings</title>
 
-<para>
-  This is an example of using <literal>warnings</literal>.
-</para>
+  <para>
+   This is an example of using <literal>warnings</literal>.
+  </para>
 
 <programlisting>
 <![CDATA[
@@ -43,22 +42,19 @@
 }
 ]]>
 </programlisting>
+ </section>
 
-</section>
-
-<section>
-
-<title>Assertions</title>
+ <section>
+  <title>Assertions</title>
 
-
-<para>
-  This example, extracted from the
-  <link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-17.09/nixos/modules/services/logging/syslogd.nix">
-    <literal>syslogd</literal> module
-  </link> shows how to use <literal>assertions</literal>. Since there
-  can only be one active syslog daemon at a time, an assertion is useful to
-  prevent such a broken system from being built.
-</para>
+  <para>
+   This example, extracted from the
+   <link xlink:href="https://github.com/NixOS/nixpkgs/blob/release-17.09/nixos/modules/services/logging/syslogd.nix">
+   <literal>syslogd</literal> module </link> shows how to use
+   <literal>assertions</literal>. Since there can only be one active syslog
+   daemon at a time, an assertion is useful to prevent such a broken system
+   from being built.
+  </para>
 
 <programlisting>
 <![CDATA[
@@ -74,7 +70,5 @@
 }
 ]]>
 </programlisting>
-
-</section>
-
+ </section>
 </section>