Journal of Applied Mathematics and Stochastic Analysis
We introduce a generalized notion of invariance for differential inclusions, using a proximal aiming condition in terms of proximal normals. A set of sufficient conditions for the weak and strong invariance in the generalized sense are presented.
Bhaskar, T. G., & Lakshmikantham, V. (2006). Generalized flow invariance for differential inclusions. Journal of Applied Mathematics and Stochastic Analysis, 2006 doi:10.1155/JAMSA/2006/49431