title: How can I test if a variable is *not* a positive integer?
body: <p>To test whether a variable is e.g. a number greater than 0, you would write:</p>
  
  <pre><code>((i &gt; 0))
  </code></pre>
  
  <p>But how would I test if the variable is <code>not</code> a number greater than 0?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>Sorry for the typo, meant <code>not a number greater than 0</code>.</p>
  
  <p><strong>EDIT 2</strong></p>
  
  <p>Sry for the poor question. The value of the variable is passed as a commandline argument, so it may be a number or not. This also needs to be checked.</p>