Optimal Continual Learning has Perfect Memory and is NP-hard

@inproceedings{knoblauch2020optimal,
  title = {Optimal Continual Learning has Perfect Memory and is NP-hard},
  author = {Jeremias Knoblauch and Hisham Husain and Tom Diethe},
  year = {2020},
  booktitle = {International Conference on Machine Learning},
  eprint = {2006.05188},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2006.05188},
}