Before revision:  As such, it is enough to sweep the graph once from left to right, paying only f(k) along the way , which is a new surprising insight into the classical MPC problem .
After revision:  As such, it is enough to sweep the graph once from left to right, paying only f(k) along the way . The fact that the width can be computed by a single f(k)-sweep of the DAG is a new surprising insight into the classical MPC problem .