title: SWI-Prolog and filename extensions: Why won't swipl recognize a file with an extension?
body: <p>I'm using SWI-Prolog's command-line interpreter swipl. I run it inside a directory containing a file <code>test.pro</code>, and try to call</p>
  
  <p><code>[test.pro].</code></p>
  
  <p>This causes swipl to spew </p>
  
  <p><code>ERROR: Syntax error: Operator expected
  ERROR: [test
  ERROR: ** here **
  ERROR: .pro] .</code></p>
  
  <p>However, if I remove the extension, it works just fine. Is there any way to pass filenames to swipl to load which have extension that won't cause this error? In fact, I'd like to know <em>what</em> is causing this error, because SWI-Prolog's website is not very helpful.</p>