title: delete array elements by certain criteria
body: <p>What's the best and way to do this:
  I have two arrays:</p>
  
  <pre><code>a=[['a','one'],['b','two'],['c','three'],['d','four']]
  </code></pre>
  
  <p>and <code>b=['two','three']</code></p>
  
  <p>I want to delete nested arrays inside <code>a</code> that include elements in <code>b</code>,to get this:</p>
  
  <pre><code>[['a','one']['d','four']
  </code></pre>
  
  <p>Thanks.</p>