find unique items in a set of arrays and remove non-uniques from arrays found
<p>Givven an object with <strong>Key</strong> as an Array (of position) and <strong>Value</strong> as an Array as well:</p>

<pre><code>// Example Object
0,2 : [6, 8, 9]
0,3 : [1, 6, 8]
0,4 : [6, 8]
0,5 : [6, 8]
0,6 : [4, 5, 8, 9]
0,7 : [5, 8]
0,8 : [4, 5, 7, 9]
</code></pre>

<p>(it was created like this:</p>

<pre><code>x = {};
x[[0,2]] = [6, 8, 9];
x[[0,3]] = [1, 6, 8];
...
</code></pre>

<p>Now, I want to narrow down my object to this, by checking if any number in an Array <strong>appears only inside this array</strong>, and not in others value's arrays, then eliminating all the other numbers inside the specific array which holds the unique number.<br/>(Rule: no duplicated inside a given array, so no need to check that):</p>

<pre><code>// Result Object
0,2 : [6, 8, 9]
0,3 : [1]
0,4 : [6, 8]
0,5 : [6, 8]
0,6 : [4, 5, 8, 9]  // now 4 becomes also a "loner"
0,7 : [5, 8]
0,8 : [7]
</code></pre>

<p>so here in Key [0,3] the Value's array was narrowed down to just [1] because 1 is a unique number not showing up in the other array.</p>

<p>I'm having trouble thinking of an efficient pattern for this...</p>
