title: PHP intersect of array of array
body: <p>I have an array of array . 
  Example like </p>
  
  <pre><code>a[0]={1,2,3};
  a[1]={2,3,4};
  **Edit** in a[2] from a[2]={4,5};
  a[2]={2,4,5};
  and more 
  </code></pre>
  
  <p>How can I find common element which exist in all array ?</p>