Abstract

Fluted Logic is essentially first-order predicate logic deprived of variables. The lack of variables results in reduced expressiveness. Nevertheless, many logical problems that can be stated in natural language, such as the famous Schubert's Steamroller, can be rendered in fluted logic. Further evidence of the expressiveness of fluted logic is its close relation to description logics. Already it has been shown that fluted logic is decidable and has the finite-model property. This paper shows that fluted logic has the exponential-model property and that deciding satisfiability is NEXPTIME-complete. It is shown further that fluted logic is 'nice, that is, it shares with first-order predicate logic the interpolation property and model preservation properties.