Opposite Segment in Discover/DW



I often want to create a "converse" segment which is the opposite of the current segment I am looking at.   For example, if I am looking at a segment of 1st Time Visitors, I might like to contrast that with all Non-1st Time Visitors.  Unfortunately, that takes a lot of extra work, especially if the segments are complex.  It would be great if there were an easy way to "create opposite of the current segment." I feel like this is a task that might be better done by an algorithm than a person or at least it can recommend something to start with...