<p dir="auto">It is unclear in the prompt whether the test function <code class="notranslate">sym(A, B, C, D, E, F)</code> is requesting the user to create a function that accomplishes:</p>
<p dir="auto"><code class="notranslate">return A △ B △ C △ D △ E △ F</code><br>
OR<br>
<code class="notranslate">return ((((A △ B) △ C) △ D) △ E) △ F</code></p>
<p dir="auto">The syntax difference is important. For the following test case:</p>
<p dir="auto"><code class="notranslate">A = [3, 3, 3, 2, 5] B = [2, 1, 5, 7] C = [3, 4, 6, 6] D = [1, 2, 3],  E = [5, 3, 9, 8] F = [1]  should return [1, 2, 4, 5, 6, 7, 8, 9]</code></p>
<p dir="auto">The first version I mentioned (the symmetric difference of ALL ARRAYS) would return<br>
<code class="notranslate">[4, 7, 8, 9]</code></p>
<p dir="auto">Whereas the second returns<br>
<code class="notranslate">[1, 2, 4, 5, 6, 7, 8, 9]</code>.</p>
<p dir="auto">I'm just wondering if we could make this clearer in the instructions? <strong>Technically</strong>, the instructions</p>
<p dir="auto"><code class="notranslate">Create a function that takes two or more arrays and returns an array of the symmetric difference (△ or ⊕) of the provided arrays.</code></p>
<p dir="auto">actually ask for the first version, not the second version, and according to my limited programming and mathematics knowledge, the test cases are wrong ...</p>
<p dir="auto">Maybe someone can clarify this?</p>
<p dir="auto">This is a bit of a formal issue, not a "bug" per se:</p>
<p dir="auto">In CSS, proper font names like Arial or "Times New Roman" should be Title Case (and in quotes where applicable).<br>
Generic font names like sans-serif or monospace should be lowercase.</p>
<p dir="auto">--- wm</p>
<p dir="auto">Challenge <a href="http://www.freecodecamp.com/challenges/set-the-font-family-of-an-element#?solution=%3Cstyle%3E%0A%20%20.red-text%20%7B%0A%20%20%20%20color%3A%20red%3B%0A%20%20%7D%0A%0A%20%20p%20%7B%0A%20%20%20%20font-size%3A%2016px%3B%0A%20%20%20%20font-family%3A%20monospace%3B%0A%20%20%7D%0A%3C%2Fstyle%3E%0A%0A%3Ch2%20class%3D%22red-text%22%3ECatPhotoApp%3C%2Fh2%3E%0A%0A%3Cp%20class%3D%22red-text%22%3EKitty%20ipsum%20dolor%20sit%20amet%2C%20shed%20everywhere%20shed%20everywhere%20stretching%20attack%20your%20ankles%20chase%20the%20red%20dot%2C%20hairball%20run%20catnip%20eat%20the%20grass%20sniff.%3C%2Fp%3E%0A%3Cp%3EPurr%20jump%20eat%20the%20grass%20rip%20the%20couch%20scratched%20sunbathe%2C%20shed%20everywhere%20rip%20the%20couch%20sleep%20in%20the%20sink%20fluffy%20fur%20catnip%20scratched.%3C%2Fp%3E%0A" rel="nofollow">Set the Font Family of an Element</a> has an issue.<br>
User Agent is: <code class="notranslate">Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.80 Safari/537.36</code>.<br>
Please describe how to reproduce this issue, and include links to screenshots if possible.</p>
<p dir="auto">My code:</p>
<div class="highlight highlight-text-html-basic notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="&lt;style&gt;
  .red-text {
    color: red;
  }

  p {
    font-size: 16px;
    font-family: monospace;
  }
&lt;/style&gt;

&lt;h2 class=&quot;red-text&quot;&gt;CatPhotoApp&lt;/h2&gt;

&lt;p class=&quot;red-text&quot;&gt;Kitty ipsum dolor sit amet, shed everywhere shed everywhere stretching attack your ankles chase the red dot, hairball run catnip eat the grass sniff.&lt;/p&gt;
&lt;p&gt;Purr jump eat the grass rip the couch scratched sunbathe, shed everywhere rip the couch sleep in the sink fluffy fur catnip scratched.&lt;/p&gt;
"><pre class="notranslate"><span class="pl-kos">&lt;</span><span class="pl-ent">style</span><span class="pl-kos">&gt;</span>
  .<span class="pl-c1">red-text</span> {
    <span class="pl-c1">color</span><span class="pl-kos">:</span> red;
  }

  <span class="pl-ent">p</span> {
    <span class="pl-c1">font-size</span><span class="pl-kos">:</span> <span class="pl-c1">16<span class="pl-smi">px</span></span>;
    <span class="pl-c1">font-family</span><span class="pl-kos">:</span> monospace;
  }
<span class="pl-kos">&lt;/</span><span class="pl-ent">style</span><span class="pl-kos">&gt;</span>

<span class="pl-kos">&lt;</span><span class="pl-ent">h2</span> <span class="pl-c1">class</span>="<span class="pl-s">red-text</span>"<span class="pl-kos">&gt;</span>CatPhotoApp<span class="pl-kos">&lt;/</span><span class="pl-ent">h2</span><span class="pl-kos">&gt;</span>

<span class="pl-kos">&lt;</span><span class="pl-ent">p</span> <span class="pl-c1">class</span>="<span class="pl-s">red-text</span>"<span class="pl-kos">&gt;</span>Kitty ipsum dolor sit amet, shed everywhere shed everywhere stretching attack your ankles chase the red dot, hairball run catnip eat the grass sniff.<span class="pl-kos">&lt;/</span><span class="pl-ent">p</span><span class="pl-kos">&gt;</span>
<span class="pl-kos">&lt;</span><span class="pl-ent">p</span><span class="pl-kos">&gt;</span>Purr jump eat the grass rip the couch scratched sunbathe, shed everywhere rip the couch sleep in the sink fluffy fur catnip scratched.<span class="pl-kos">&lt;/</span><span class="pl-ent">p</span><span class="pl-kos">&gt;</span></pre></div>