Source: Notre Dame J. Formal Logic Volume 50, Number 2
(2009), 119-132.
Sections 1 and 2 respectively raise and settle the question of whether, if an affirmative modality collapses (reduces to the null modality, that is) in a normal modal logic, then all modalities of the same length collapse in that logic, while Section 3 considers some special cases of an analogous phenomenon for congruential modal logics, closing with a general question about collapsing modalities in this broader range of logics.
Full-text: Access denied (no subscription
detected)
We're sorry, but we are unable to provide
you with the full text of this article because we are not able to identify
you as a subscriber.
If you have a personal subscription to
this journal, then please login. If you are already logged in, then you
may need to update your profile to register your subscription.
Read more about accessing full-text
References
[1] Bellissima, F., and M. Mirolli, "A general treatment of equivalent modalities", The Journal of Symbolic Logic, vol. 54 (1989), pp. 1460--71.
[2] van Benthem, J. F. A. K., "Modal reduction principles", The Journal of Symbolic Logic, vol. 41 (1976), pp. 301--12.
[3] Chellas, B., "Modalities in normal systems containing the S5 axiom", pp. 261--65 in Intention and Intentionality: Essays in Honour of G. E. M. Anscombe, edited by C. Diamond and J. Teichman, Harvester Press, Brighton, 1979.
[4] Chellas, B. F., Modal Logic. An Introduction, Cambridge University Press, Cambridge, 1980.
Mathematical Reviews (MathSciNet):
MR556867
[5] Fitch, F. B., "A correlation between modal reduction principles and properties of relations", Journal of Philosophical Logic, vol. 2 (1973), pp. 97--101.
[6] Giesl, J., and D. Kapur, "Dependency pairs for equational rewriting", pp. 93--107 in Rewriting Techniques and Applications (Utrecht, 2001), edited by A. Middeldorp, vol. 2051 of Lecture Notes in Computer Science, Springer, Berlin, 2001.
[7] Humberstone, L., "Negation by iteration", Theoria, vol. 61 (1995), pp. 1--24.
[8] Humberstone, L., "Two-dimensional adventures", Philosophical Studies, vol. 118 (2004), pp. 17--65.
[9] Humberstone, L., and T. Williamson, "Inverses for normal modal operators", Studia Logica, vol. 59 (1997), pp. 33--64.
[10] Parry, W. T., "Modalities in the survey" system of strict implication, The Journal of Symbolic Logic, vol. 4 (1939), pp. 137--54.
[11] Williamson, T., "Two incomplete anti-realist modal epistemic logics", The Journal of Symbolic Logic, vol. 55 (1990), pp. 297--314.
[12] Williamson, T., "Continuum many maximal consistent normal bimodal logics with inverses", Notre Dame Journal of Formal Logic, vol. 39 (1998), pp. 128--34.