@InProceedings{Elliott89:DependentHOU,
  author       = {Conal Elliott},
  title        = {Higher-Order Unification with Dependent Types},
  url          = {http://conal.net/papers/rta89.pdf},
  booktitle    = {Rewriting Techniques and Applications},
  year         = 1989,
  editor       = {N. Dershowitz}
}