Research topics include:

• Verification of Hybrid Systems.
  
• Modal Logics:
  Translation from modal logic into first-order predicate logic.
  Modal logic correspondence and completeness theory.
  Resolution-based calculi for modal logics.
  Theory inference rules tailored for modal logics.
• Temporal Logics:
  Resolution-based calculi for temporal logics.
  Temporal logic correspondence and completeness theory.
• Extraction of first-order theories:
  Saturation techniques, theory rules instead of theory clauses.
• Applications of Second-Order Quantifier Elimination:
  Correspondence Theory, Abduction, Circumscription, Interpolation.