  The Step out-Step in sequencing game is a particular example of a game from
the sequencing game framework of Curiel, Perderzoli, and Tijs, where coalitions
of players in a queue may reorder themselves to improve the their overall cost,
under some restrictions. Musegaas, Borm and Quant proved, in two papers, that a
simple greedy algorithm correctly computes the valuation of a coalition, and
that the game is convex. These proofs entail rather involved case analyses; in
this note, we give short proofs of both results.
