has-same-nodes(node-set-1, node-set-2)
This returns a boolean that is true if and only if node-set-1 and node-set-2 contain the same set of nodes. Note this is quite different from the "=" operator, which tests whether there is a pair of nodes with the same string-value.
This function is deprecated, since it is now possible to achieve the same effect
using standard functions and operators: for example (assuming that $A and $B contain no duplicates), write
count($A) = count($B) and count($A except $B) = 0