CHAI PI Siddharth Srivastava, along with his co-authors Sarath Sreedharan, Rao Kambhampati, David Smith, published “Why Can’t You Do That, HAL? Explaining Unsolvability of Planning Tasks” in the 2019 International Joint Conference on Artificial Intelligence (IJCAI) proceedings. The paper discusses how, as anyone who has talked to a 3-year-old knows, explaining why something can’t be done can be harder than explaining a solution to a problem. The paper then goes into new work in having AI explain unsolvability.