Completeness and Correspondence in Hybrid Logic via an Extension of SQEMA

We develop a new algorithm, based upon the SQEMA-algorithm, for computing first-order frame correspondents of hybrid formulas. It is shown that the success of this algorithm on an input formula guarantees its sd-persistence and hence the completeness of the logic obtained by adding that formula as axiom to the basic hybrid system. These results are employed to obtain a hybridized extension of Sahlqvist's theorem.