title: PHP array combinations
body: <p>I have an array of 7 numbers (1,2,3,4,5,6,7) and I want to choose 5 of the numbers like<br />
  (1,2,3,4,5), (1,2,3,4,6), (1,2,3,4,7).<br />
  Note that (1,2,3,4,5) is equal to (4,5,3,1,2), so only one of those should be included in the output.</p>
  <p>I would like to know if there is a function in PHP or any algorithm that can do this ?
  I have no idea where to start from.
  Can you help me ?</p>
  <p>I want all the combinations of 7 given numbers ( they are taken from an array ) put into 5 slots, disregarding order.</p>