Representing regular pseudocomplemented Kleene algebras by   tolerance-based rough sets
  We show that any regular pseudocomplemented Kleene algebra defined on an algebraic lattice is isomorphic to a rough set Kleene algebra determined by a tolerance induced by an irredundant covering. 
Jouni J\"arvinen and S\'andor Radeleczki
math.CO cs.FL cs.LO math.RT