@Techreport{CM11tech,
  AUTHOR =   {Peter {\v C}erno and Franti{\v s}ek Mr{\'a}z},
  TITLE =    {Delta-Clearing Restarting Automata and CFL},
  INSTITUTION =  {Charles University, Faculty of Mathematics and Physics},
  YEAR =     {2011},
  NUMBER =   {8/2011},
  ADDRESS =  {Prague},
  URL =      {http://popelka.ms.mff.cuni.cz/cerno/files/cerno_mraz_dclra_and_cfl.pdf},
  ABSTRACT = {Delta-clearing restarting automata represent a new restricted model of restarting automata which,
              based on a limited context, can either delete a substring of the current content of its tape or
              replace a substring by a special auxiliary symbol $\Delta$, which cannot be overwritten anymore,
              but it can be deleted later. The main result of this paper consists in the proving that beside
              their limited operations, Delta-clearing restarting automata recognize all context-free languages.},
  KEYWORDS = {analysis by reduction, context-free languages, Delta-clearing restarting automata, formal languages},
}