title: Are negative integers allowed in sets?
body: <p>I know sets can't have more than 255 elements in FPC, however, are negative integers allowed?</p>
  
  <p>I've stumbled upon this and haven't been able to find anything related to it online.</p>
  
  <pre><code>PROGRAM test;
  TYPE rg = -10..0;
      negatives = set of rg;
  </code></pre>
  
  <p>I get this  compiling error.</p>
  
  <pre><code>test.pas(3,25) Error: illegal type declaration of set elements
  </code></pre>
  
  <p>I suspect this error comes from the negative integers because if i define the range as <code>0..5</code> for example, it compiles alright.</p>