title: How to join search patterns in CLiPS pattern.search
body: <p>I do pattern matching in text using CLiPS pattern.search (Python 2.7).
  I need to extract both phrases that correspond to 'VBN NP' and 'NP TO NP'.
  I can do it separately and then join results:</p>
  
  <pre><code>from pattern.en import parse,parsetree
  from pattern.search import search
  
  text="Published case-control studies have a lot of information about susceptibility to asthma."
  sentenceTree = parsetree(text, relations=True, lemmata=True)
  matches = []
  for match in search("VBN NP",sentenceTree):
      matches.append(match.string)
  for match in search("NP TO NP",sentenceTree):
      matches.append(match.string)
  print matches
  # Output: [u'Published case-control studies', u'susceptibility to asthma']
  </code></pre>
  
  <p>But id I want to join this to one search pattern. If I try this I get no results at all.</p>
  
  <pre><code>matches = []
  for match in search("VBN NP|NP TO NP",sentenceTree):
      matches.append(match.string)
  print matches
  #Output: []
  </code></pre>
  
  <p><a href="http://www.clips.ua.ac.be/pages/pattern-search" rel="nofollow noreferrer">Official documentation</a> gives no clues for this. I also had tried '{VBN NP}|{NP TO NP}' '[VBN NP]|[NP TO NP]' but without any luck.</p>
  
  <p><strong>Question is:</strong>
  Is it possible to join search patterns in CLiPS pattern.search? 
  And if answer is "yes" then how to do it?</p>