Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T19:46:22.889Z Has data issue: false hasContentIssue false

Canonical formulas for K4. Part II: Cofinal subframe logics

Published online by Cambridge University Press:  12 March 2014

Michael Zakharyaschev*
Affiliation:
II. Mathematisches Institut, Freie Universität Berlin, Arnimallee 3, D-14195 Berlin, Germany, E-mail: mishaz@math.fu-berlin.de

Extract

This paper is a continuation of Zakharyaschev [25], where the following basic results on modal logics with transitive frames were obtained:

• With every finite rooted transitive frame and every set of antichains (which were called closed domains) in two formulas α (, , ⊥) and α(, ) were associated. We called them the canonical and negation free canonical formulas, respectively, and proved the Refutability Criterion characterizing the constitution of their refutation general frames in terms of subreduction (alias partial p-morphism), the cofinality condition and the closed domain condition.

• We proved also the Completeness Theorem for the canonical formulas providing us with an algorithm which, given a modal formula φ, returns canonical formulas α(i, i), ⊥), for i = 1,…, n, such that

if φ is negation free then the algorithm instead of α(i, i, ⊥) can use the negation free canonical formulas α(i, i). Thus, every normal modal logic containing K4 can be axiomatized by a set of canonical formulas.

In this Part we apply the apparatus of the canonical formulas for establishing a number of results on the decidability, finite model property, elementarity and some other properties of modal logics within the field of K4.

Our attention will be focused on the class of logics which can be axiomatized by canonical formulas without closed domains, i.e., on the logics of the form

Adapting the terminology of Fine [11], we call them the cofinal subframe logics and denote this class by . As was shown in Part I, almost all standard modal logics are in .

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Bull, R. A., That all normal extensions of S4.3 have the finite model property, Zeitschrift für Mathematische Logik und Grundlagen der Mathematik, vol. 12 (1966), pp. 341344.Google Scholar
[2]Chagrov, A. V., On the polynomial finite model property of modal and intermediate logics, Mathematical logic, mathematical linguistics and algorithm theory, Kalinin State University, Kalinin, 1983, Russian, pp. 7583.Google Scholar
[3]Chagrov, A. V. and Zakharyaschev, M. V., On the independent axiomatizability of modal and intermediate logics, Journal of Logic and Computation, vol. 5 (1995), pp. 287302.Google Scholar
[4]Chagrov, A. V. and Zakharyaschev, M.V., The undecidability of the disjunction property of propositional logics and other related problems, this Journal, vol. 58 (1993), pp. 9671002.Google Scholar
[5]Chagrova, L. A., On first-order definability of intuitionistic formulas with restrictions on occurrences of connectives, Logical methods for constructing effective algorithms, Kalinin State University, Kalinin, 1986, Russian, pp. 135136.Google Scholar
[6]Chagrova, L. A., On the preservation of first-order properties under the embedding of intermediate logics in modal logics, Proceedings of the Xth USSR conference for mathematical logic, Alma-Ata, 1990, Russian, p. 163.Google Scholar
[7]Chagrova, L. A., An undecidable problem in correspondence theory, this Journal, vol. 56 (1991), pp. 12611272.Google Scholar
[8]Feys, R., Modal logic, Louvain: E. Nauwelaerts, Paris, 1965.Google Scholar
[9]Fine, K., The logics containing S4.3, Zeitschrift für Mathematische Logik und Grundlagen der Mathematik, vol. 17 (1971), pp. 371376.CrossRefGoogle Scholar
[10]Fine, K., Some connections between elementary and modal logic, Proceedings of the third scandinavian logic symposium (Kanger, S., editor), North-Holland, Amsterdam., 1975, pp. 1531.Google Scholar
[11]Fine, K., Logics containing K4, Part 11, this Journal, vol. 50 (1985), pp. 619651.Google Scholar
[12]Kracht, M., Internal definability and completeness in modal logic, Ph.D. thesis, Freie Universität, Berlin, 1990.Google Scholar
[13]Logic notebook, Institute of Mathematics, 1986.Google Scholar
[14]Maksimova, L. L., Pretabular extensions ofLewis S4, Algebra and Logic, vol. 14 (1975), pp. 1633.Google Scholar
[15]Maksimova, L. L. and Rybakov, V.V., On the lattice of normal modal logics, Algebra and Logic, vol. 13 (1974), pp. 188216, Russian.Google Scholar
[16]McKay, C. G., The decidability of certain intermediate logics, this Journal, vol. 33 (1968), pp. 258264.Google Scholar
[17]Ono, H. and Nakamura, A., On the size of refutation Kripke models for some linear modal and tense logics, Studia Logica, vol. 39 (1980), pp. 325333.CrossRefGoogle Scholar
[18]Rodenburg, Rh., Intuitionistic correspondence theory, Ph.D. thesis, University of Amsterdam, 1986.Google Scholar
[19]Segerberg, K., An essay in classical modal logic, Philosophical Studies, vol. 13 (1971), University of Uppsala.Google Scholar
[20]Shimura, T., Kripke completeness of some intermediate predicate logics with the axiom of constant domain and a variant of canonical formulas, Studia Logica, vol. 52 (1993), pp. 2340.Google Scholar
[21]Zakharyaschev, M. V., On intermediate logics, Soviet Mathematics Doklady, vol. 27 (1983), pp. 274277.Google Scholar
[22]Zakharyaschev, M. V., Syntax and semantics of superintuitionistic and modal logics, Ph.D. thesis, Moscow, 1984, Russian.Google Scholar
[23]Zakharyaschev, M. V., Modal companions of intermediate logics: syntax, semantics and preservation theorems, Mathematical Sbornik, vol. 180 (1989), pp. 14151427, English translation: Mathematics of the USSR Sbornik, vol.68 (1991), pp.277–289.Google Scholar
[24]Zakharyaschev, M. V., Syntax and semantics of intermediate logics, Algebra and Logic, vol. 28 (1989), pp. 262282.Google Scholar
[25]Zakharyaschev, M. V., Canonical formulas for K4. part 1: Basic results, this Journal, vol. 57 (1992), pp. 13771402.Google Scholar
[26]Zakharyaschev, M. V., Intermediate logics with disjunction free axioms are canonical, IGPL Newsletter, vol. 1 (1992), no. 4, pp. 78.Google Scholar
[27]Zakharyaschev, M. V., Canonical formulas for modal and superintuitionistic logics: A short outline, Modal logic audits neighbours (de Rijke, M., editor), Dordrecht, Kluwer Academic Publishers, 1995, in print.Google Scholar
[28]Zakharyaschev, M. V. and Popov, S.V., On the complexity of countermodels for intuitionistic calculus, Institute of Applied Mathematics, the USSR Academy of Sciences no. 45, 1980, preprint, Russian.Google Scholar