Before revision:  We reveal that the Lipschitz continuity depends on the types of constraints of adversarial attacks in the binary linear classification . Specifically, under the L2 constraints, the adversarial loss is smooth except at zero.
After revision:  We reveal that the constraint of adversarial attacks is one cause of the non-smoothness and that the smoothness depends on the types of constraints of adversarial attacks in the binary linear classification . Specifically, under the L2 constraints, the adversarial loss is smooth except at zero.