Congratulations to the authors of the #IJCAI2021 distinguished papers

The IJCAI distinguished paper awards recognise some of the best papers presented at the conference each year. This year, three articles received the accolade of distinguished paper, with a further article receiving an honourable mention. Learning generalized unsolvability heuristics for classical planning Simon Ståhlberg, Guillem Francès, Jendrik Seipp Recent work in classical planning has introduced dedicated techniques for detecting unsolvable states, that is, states from which no goal state can be reached. The authors approach the problem from a generalized planning perspective and learn first order-like formulas that characterize unsolvability for entire planning domains. On the relation between approximation fixpoint theory and justification theory Simon Marynissen, Bart Bogaerts, Marc Denecker Approximation Fixpoint Theory (AFT) and Justification Theory (JT) are two frameworks to unify logical formalisms.