1. Editorial

   • Andrzej Skowron

   EditorialNotes Pages: 1 - 1

2. The logics of orthoalgebras

   • Maria Luisa Dalla Chiara
   • Roberto Giuntini

   OriginalPaper Pages: 3 - 22

3. Undecidability, incompleteness and Arnol'd problems

   • Newton C. A. da Costa
   • Francisco A. Doria

   OriginalPaper Pages: 23 - 32

4. Explicit algebraic models for constructive and classical theories with non-standard elements

   • Albert G. Dragalin

   OriginalPaper Pages: 33 - 61

5. Tableaus for many-valued modal logic

   • Melvin Fitting

   OriginalPaper Pages: 63 - 87

6. Symmetrical Heyting algebras with a finite order type of operators

   • Luisa Iturrioz

   OriginalPaper Pages: 89 - 98

7. On variable separation in modal and superintuitionistic logics

   • Larisa Maksimova

   OriginalPaper Pages: 99 - 112

8. Averaging the truth-value in Łukasiewicz logic

   • Daniele Mundici

   OriginalPaper Pages: 113 - 127

9. The abstract variable-binding calculus

   • Don Pigozzi
   • Antonino Salibra

   OriginalPaper Pages: 129 - 179

10. Maximal weakly-intuitionistic logics

    • A. M. Sette
    • Walter A. Carnielli

    OriginalPaper Pages: 181 - 203

11. A duality between Pawlak's knowledge representation systems and bi-consequence systems

    • Dimiter Vakarelov

    OriginalPaper Pages: 205 - 228