@inproceedings{Beckert94f,
   author        = {Bernhard Beckert},
   title         = {Using Mixed Universal and Rigid {$E$}-Unification to
                    Handle Equality in Universal Formula Semantic Tableaux},
   booktitle     = {Adding Equality to Theorem Provers, Workshop
                    of the DFG-Schwerpunkt ``Deduktion''},
   venue         = {Leipzig, Germany},
   year          = {1994}
}