Before revision:  In fact, we show in Doval and Skreta (2018) that they can be used to provide an upper bound on the number of posteriors a designer with limited commitment uses in his optimal mechanism .
After revision:  We illustrate our results with applications to mechanism design with limited commitment ( Doval and Skreta (2018) that they can be used to provide an upper bound on the number of posteriors a designer with limited commitment uses in his optimal mechanism .