Ten kids line up for recess. The names of the kids are: {Abe, Ben, Cam, Don, Eli, Fran, Gene, Hal, Ike, Jan}. Let S be the set of all possible ways to line up the kids. For example, one ordering might be: (Fran, Gene, Hal, Jan, Abe, Don, Cam, Eli, Ike, Ben) The names are listed in order from left to right, so Fran is at the front of the line and Ben is at the end of the line.
Let T be the set of all possible ways to line up the kids in which Gene is ahead of Don in the line. Note that Gene does not have to be immediately ahead of Don. For example, the ordering shown above is an element in T.
Now define a function f whose domain is S and whose target is T. Let x be an element of S, so x is one possible way to order the kids. If Gene is ahead of Don in the ordering x, then f(x) = x. If Don is ahead of Gene in x, then f(x) is the ordering that is the same as x, except that Don and Gene have swapped places.
What is the output of f on the following input? (Fran, Gene, Hal, Jan, Abe, Don, Cam, Eli, Ike, Ben)