title: Troubles using NONE when filtering an NSArray with an NSSet
body: <p>I'm trying to filter an NSArray by excluding the elements that are in an NSSet. I'm doing something like this:</p>
  
  <pre><code>    NSMutableArray* a = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", nil];
      NSSet* set = [NSSet setWithObjects:@"2", nil];
      NSPredicate *predicate = [NSPredicate predicateWithFormat:@"NONE SELF IN %@", set];
      NSArray* b = [a filteredArrayUsingPredicate:predicate];
  </code></pre>
  
  <p>However, this code throws an exception:</p>
  
  <blockquote>
    <p>Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'The left hand side for an ALL or ANY operator must be either an NSArray or an NSSet</p>
  </blockquote>
  
  <p>What is that I'm doing wrong?</p>