title: Need confirmation about PEG's semantic predicates in pyparsing
body: <p>The <a href="http://en.wikipedia.org/wiki/Parsing_expression_grammar" rel="nofollow">PEG</a> paper describes two semantic predicate parsing expressions:</p>
  
  <ol>
  <li>And predicate <code>&amp;e</code></li>
  <li>Not predicate <code>!e</code></li>
  </ol>
  
  <p>Does pyparsing support the And predicate ? Or is that just a synonym for the sequencing parsing expression ? In that case it should be equivalent to the <code>And</code> class. Correct?</p>
  
  <p>Does <code>NotAny</code> represent the Not predicate?</p>
  
  <p>Specifically do they conform to the spec's behaviour:</p>
  
  <blockquote>
    <p>The parsing expression foo &amp;(bar) matches and consumes the text "foo" but only if it is followed by the text "bar". The parsing expression foo !(bar) matches the text "foo" but only if it is not followed by the text "bar". The expression !(a+ b) a matches a single "a" but only if it is not the first in an arbitrarily-long sequence of a's followed by a b.</p>
  </blockquote>