•?S S2 AND S5
•            4055  S2
•           58984  S5
•      S6     138  S2 AND S5
•?DS
•Set     Items   Description
•S1      54890   MATHEMATICS
•S2       4055   FEAR
•S3        116   S1 AND S2
•S4     169200   1 AND 2
•S5      58984   MATH OR MATHEMATICS
•S6        138   S2 AND S5
•?
So, my new set S6 is a little larger than set S3.  It is most likely a superior set of search results from a completeness standpoint.

I told you I use that DS command a lot!