When the Gomory-Chvátal closure coincides with the integer hull

Gomory-Chvátal cuts are prominent in integer programming. The Gomory-Chvátal closure of a polyhedron is the intersection of the half spaces defined by all its Gomory-Chvátal cuts. We prove that it is NP-hard to decide whether the Gomory-Chvátal closure of a rational polyhedron P is identical to the integer hull of P. An earlier version of this paper appeared in the proceedings of IPCO 2016.