@Unpublished{alti:prog94,
  author = 	 {Thorsten Altenkirch},
  title = 	 {Programming + Verification = Progification},
  note = 	 {available from {\tt http://www.cs.nott.ac.uk/\~{}txa/publ/progify94.pdf}},
  OPTkey = 	 {},
  OPTmonth = 	 {},
  year =	 {1994},
  www =          {http://www.cs.nott.ac.uk/~txa/publ/progify94.pdf},
  OPTannote = 	 {}
}