diff --git a/docs/Graphmath.Quatern.html b/docs/Graphmath.Quatern.html
index 7c8aa82..67aecb3 100644
--- a/docs/Graphmath.Quatern.html
+++ b/docs/Graphmath.Quatern.html
@@ -242,8 +242,7 @@ <h2>Functions</h2>
   <div class="docstring"><p><code class="inline">add(lhs, rhs)</code> add two quaternions.</p>
 <p><code class="inline">lhs</code> is the first <code class="inline">quatern</code></p>
 <p><code class="inline">rhs</code> is the second <code class="inline">quatern</code></p>
-<p>It returns a <code class="inline">quatern</code> of the form</p>
-<pre><code>{ lhs&lt;sub&gt;w&lt;/sub&gt; + rhs&lt;sub&gt;w&lt;/sub&gt;, lhs&lt;sub&gt;x&lt;/sub&gt; + rhs&lt;sub&gt;x&lt;/sub&gt;, lhs&lt;sub&gt;y&lt;/sub&gt; + rhs&lt;sub&gt;y&lt;/sub&gt;, lhs&lt;sub&gt;z&lt;/sub&gt; + rhs&lt;sub&gt;z&lt;/sub&gt; }.</code></pre>
+<p>It returns a <code class="inline">quatern</code> of the form { lhs<sub>w</sub> + rhs<sub>w</sub>, lhs<sub>x</sub> + rhs<sub>x</sub>, lhs<sub>y</sub> + rhs<sub>y</sub>, lhs<sub>z</sub> + rhs<sub>z</sub> }.</p>
 </div>
   
 </div>
@@ -652,8 +651,7 @@ <h2>Functions</h2>
   <div class="docstring"><p><code class="inline">subtract(lhs, rhs)</code> subtract two quaternions.</p>
 <p> <code class="inline">lhs</code> is the first <code class="inline">quatern</code></p>
 <p> <code class="inline">rhs</code> is the second <code class="inline">quatern</code></p>
-<p> It returns a <code class="inline">quatern</code> of the form</p>
-<pre><code>{ lhs&lt;sub&gt;w&lt;/sub&gt; - rhs&lt;sub&gt;w&lt;/sub&gt;, lhs&lt;sub&gt;x&lt;/sub&gt; - rhs&lt;sub&gt;x&lt;/sub&gt;, lhs&lt;sub&gt;y&lt;/sub&gt; - rhs&lt;sub&gt;y&lt;/sub&gt;, lhs&lt;sub&gt;z&lt;/sub&gt; - rhs&lt;sub&gt;z&lt;/sub&gt; }.</code></pre>
+<p> It returns a <code class="inline">quatern</code> of the form { lhs<sub>w</sub> - rhs<sub>w</sub>, lhs<sub>x</sub> - rhs<sub>x</sub>, lhs<sub>y</sub> - rhs<sub>y</sub>, lhs<sub>z</sub> - rhs<sub>z</sub> }.</p>
 </div>
   
 </div>
diff --git a/lib/Quatern.ex b/lib/Quatern.ex
index 3efaffc..f004a61 100644
--- a/lib/Quatern.ex
+++ b/lib/Quatern.ex
@@ -82,8 +82,7 @@ defmodule Graphmath.Quatern do
 
     `rhs` is the second `quatern`
 
-    It returns a `quatern` of the form
-        { lhs<sub>w</sub> + rhs<sub>w</sub>, lhs<sub>x</sub> + rhs<sub>x</sub>, lhs<sub>y</sub> + rhs<sub>y</sub>, lhs<sub>z</sub> + rhs<sub>z</sub> }.
+    It returns a `quatern` of the form { lhs<sub>w</sub> + rhs<sub>w</sub>, lhs<sub>x</sub> + rhs<sub>x</sub>, lhs<sub>y</sub> + rhs<sub>y</sub>, lhs<sub>z</sub> + rhs<sub>z</sub> }.
     """
     @spec add(quatern, quatern) :: quatern
     def add(lhs, rhs) do
@@ -100,8 +99,7 @@ defmodule Graphmath.Quatern do
 
      `rhs` is the second `quatern`
 
-     It returns a `quatern` of the form
-        { lhs<sub>w</sub> - rhs<sub>w</sub>, lhs<sub>x</sub> - rhs<sub>x</sub>, lhs<sub>y</sub> - rhs<sub>y</sub>, lhs<sub>z</sub> - rhs<sub>z</sub> }.
+     It returns a `quatern` of the form { lhs<sub>w</sub> - rhs<sub>w</sub>, lhs<sub>x</sub> - rhs<sub>x</sub>, lhs<sub>y</sub> - rhs<sub>y</sub>, lhs<sub>z</sub> - rhs<sub>z</sub> }.
     """
     @spec subtract(quatern, quatern) :: quatern
     def subtract(lhs, rhs) do