A Calculus-Independent Proof Data Structure<pre>@techreport{DA-05-a,
  author        = {Dominik Dietrich and Serge Autexier},
  title         = {A Calculus-Independent Proof Data Structure},
  type          = {SEKI Report},
  number        = {SR-05-03},
  institution   = {Fachrichtung Informatik, Universit\"at des Saarlandes, Saarbr\"ucken, Germany},
  year          = {2005},
}
</pre>