@inproceedings{lh09pdt,
 author = {Daniel R. Licata and Robert Harper},
 title = {Positively dependent types},
 booktitle = {PLPV '09: Proceedings of the 3rd Workshop on Programming Languages Meets Program Verification},
 year = {2009},
 isbn = {978-1-60558-330-3},
 pages = {3--14},
 location = {Savannah, GA, USA},
 publisher = {ACM},
 address = {New York, NY, USA},
 }