@TechReport{HoSatTob98,
  author = 	 {I. Horrocks and U. Sattler and S. Tobies},
  title = 	 {A PSpace-algorithm for deciding
      {$\mathcal{ALCNI}_{R^+}$}-satisfiability},
  institution =  {LuFG Theoretical Computer Science, RWTH Aachen},
  year = 	 1998,
 type           = {LTCS-Report},
  number =	 {LTCS-98-08},
  issuedate =    { October 1, 1998},
  keywords =     { Description Logic, Complexity }
}