title: Compare a value to null. Why is this true?
body: <p>Why is</p>
  
  <pre><code>isTRUE(NULL != 2)
  [1] FALSE
  </code></pre>
  
  <p>And how would I receive TRUE?</p>
  
  <p>In my real case I have variables and I want to process something, if the values differ. However, when one value is NULL I don't recognize them as different!</p>