Available since: 6.2.0
Time complexity: O(L + (N-K)log(N)) worst case where L is the total number of elements in all the sets, N is the size of the first set, and K is the size of the result set.
Computes the difference between the first and all successive input sorted sets
and stores the result in
destination. The total number of input keys is
Keys that do not exist are considered to be empty sets.
destination already exists, it is overwritten.
Integer reply: the number of elements in the resulting sorted set at