Fluted logic is a fragment of first-order logic without function symbols in which the arguments of atomic subformulae form ordered sequences. A consequence of this restriction is that, whereas first-order logic is only semi-decidable, fluted logic is decidable. In this paper we present a sound, complete and terminating inference procedure for fluted logic. Our characterisation of fluted logic is in terms of a new class of so-called fluted clauses. We show that this class is decidable by an ordering refinement of first-order resolution and a new form of dynamic renaming, called separation.
The long version is Technical Report UMCS-00-3-1, University of Manchester.