title: Ordered combinations without repetition in php?
body: <p>i have the following array:</p>
  
  <p>Array("one", "two", "three", "four");</p>
  
  <p>and i need a function that outputs all the ordered combinations of the array elements without repetition. The output should be</p>
  
  <pre><code>one
  one two
  one two three
  one two three four
  two
  two three
  two three four
  three
  three four
  four
  </code></pre>
  
  <p>The output should not include:</p>
  
  <pre><code>one one
  one two four
  two one three
  four two three
  </code></pre>
  
  <p>And so on ...</p>
  
  <p>Does anybody of you have already implemented this kind of alghoritm?</p>