Two Forms of One Useful Logic: Existential Fixed Point Logic and Liberal Datalog
- Andreas Blass ,
- Yuri Gurevich
Bulletin of the European Association for Theoretical Computer Science | , Vol 95: pp. 164-182
A natural liberalization of Datalog is used in the Distributed Knowledge Authorization Language (DKAL). We show that the expressive power of this liberal Datalog is that of existential fixed-point logic. The exposition is self-contained.