Takes two list arguments.
This function returns:
1 -- the list contains all elements contained in another list
0 (zero) -- the list does not contain all elements contained in the second list
The following expression returns 0.
<containsAll>
   <ref>fruitlist</ref>
   <list>
      <s>oranges</s>
      <s>wiper blades</s>
   </list>
</containsAll>