@article{JMLR:v23:21-0730,
  author  = {Edward Wagstaff and Fabian B. Fuchs and Martin Engelcke and Michael A. Osborne and Ingmar Posner},
  title   = {Universal Approximation of Functions on Sets},
  journal = {Journal of Machine Learning Research},
  year    = {2022},
  volume  = {23},
  number  = {151},
  pages   = {1--56},
  url     = {http://jmlr.org/papers/v23/21-0730.html}
}