@Article{harper+:lf-theory,
  author = 	 {Robert Harper and Frank Pfenning},
  title = 	 {On Equivalence and Canonical Forms in the {LF} Type Theory},
  journal = 	 {ACM Trans. on Computational Logic},
  year = 	 2003,
  volume =	 {?},
  number =	 {?},
  pages =	 {?--?},
  note =	 {(To appear)}
}