@Article{crary+:polyrecrelns,
  author = 	 {Karl Crary and Robert Harper},
  title = 	 {Syntactic Logical Relations for Polymorphic and Recursive Types},
  journal = 	 {Electronic Notes in Theoretical Computer Science},
  year = 	 2007,
  volume = 	 {?},
  number = 	 {?},
  pages = 	 {?},
  month = 	 {?},
  note = 	 {(To appear.)}}