Logic in Computer Science, Symposium on (1999)
July 2, 1999 to July 5, 1999
Erich Grädel , RWTH Aachen
Igor Walukiewicz , Warsaw University
Guarded fixed point logics are obtained by adding least and greatest fixed points to the guarded fragments of first-order logic that were recently introduced by Andr?ka, van Benthem and N?meti. Guarded fixed point logics can also be viewed as the natural common extensions of the modal mu-calculus and the guarded fragments. We prove that the satisfiability problems for guarded fixed point logics are decidable and complete for deterministic double exponential time. For guarded fixed point sentences of bounded width, the most important case for applications, the satisfiability problem is EXPTIME-complete.
E. Grädel and I. Walukiewicz, "Guarded Fixed Point Logic," Logic in Computer Science, Symposium on(LICS), Trento, Italy, 1999, pp. 45.