Neural networks are increasingly applied in safety critical domains, their verification thus is gaining importance. A large class of recent algorithms for proving input-output relations of feed-forward neural networks are based on linear relaxations and symbolic interval propagation. However, due to variable dependencies, the approximations deteriorate with increasing depth of the network. In this paper we present DPNeurifyFV, a novel branch-and-bound solver for ReLU networks with low dimensional input-space that is based on symbolic interval propagation with fresh variables and input-splitting. A new heuristic for choosing the fresh variables allows to ameliorate the dependency problem, while our novel splitting heuristic, in combination with several other improvements, speeds up the branch-and-bound procedure. We evaluate our approach on the airborne collision avoidance networks ACAS Xu and demonstrate runtime improvements compared to state-of-the-art tools.

本文提出了一种新的基于符号区间传播和变量分裂的分支定界求解器DPNeurifyFV，该方法采用新的启发式算法来选择区间变量，以改善变量相关性问题，在结合其他改进措施的情况下，可以显著提高深度学习神经网络验证的效率，并在空中碰撞避免网络ACAS Xu上实现了运行时改进。

神经网络验证的优化符号化区间传播