Pure Modal Logic of Names and Tableau Systems

By a pure modal logic of names (PMLN) we mean a quantifier-free formulation of such a logic which includes not only traditional categorical, but also modal categorical sentences with modalities de re and which is an extension of Propositional Logic. For categorical sentences we use two interpretations: a “natural” one; and Johnson and Thomason’s interpretation, which is suitable for some reconstructions of Aristotelian modal syllogistic (Johnson in Notre Dame J Form Logic 30(2):271–284, 1989; Thomason in J Philos Logic 22(2):111–128, 1993 and J Philos Logic 26:129–141, 1997. In both cases we use Johnson-like models (1989). We also analyze different kinds of versions of PMLN, for both general and singular names. We present complete tableau systems for the different versions of PMLN. These systems enable us to present some decidability methods. It yields “strong decidability” in the following sense: for every inference starting with a finite set of premises (resp. every syllogism, every formula) we can specify a finite number of steps to check whether it is logically valid. This method gives the upper bound of the cardinality of models needed for the examination of the validity of a given inference (resp. syllogism, formula).     

A conjunction in closure spaces

This paper is closely related to investigations of abstract properties of basic logical notions expressible in terms of closure spaces as they were begun by A. Tarski (see [6]). We shall prove many properties of ω-conjunctive closure spaces (X is ω-conjunctive provided that for every two elements of X their conjunction in X exists). For example we prove the following theorems:

1. For every closed and proper subset of an ω-conjunctive closure space its interior is empty (i.e. it is a boundary set).
2. If X is an ω-conjunctive closure space which satisfies the ω-compactness theorem and \(\hat P\) [X] is a meet-distributive semilattice (see [3]), then the lattice of all closed subsets in X is a Heyting lattice.
3. A closure space is linear iff it is an ω-conjunctive and topological space.
4. Every continuous function preserves all conjunctions.

     

Traces left on visual selective attention by stimuli that are not consciously identified

Briefly presented information, even if unidentifiable, may speed or delay required responses to following events. It has been assumed that this priming of the motor system may occur without affecting attention to priming and following stimuli. In contrast to this notion, the present study reports that such unidentified stimuli have effects on a physiological indicator of the attentional system. A lateral posterior electroencephalogram component was evoked by laterally presented relevant shapes, reflecting shifts of attention to those shapes. This component was absent, however, when the relevant shape was preceded by a similar shape at the same location, even if this shape was completely masked by metacontrast. The attentional shift evidently became unnecessary in this situation. Thus, unidentifiable information may leave some trace for attention-controlled selection of the following event.     

The logic of questions as a theory of erotetic arguments

This paper argues for the idea that the logic of questions should focus its attention on the analysis of arguments in which questions play the role of conclusions. The relevant concepts of validity are discussed and the concept of the logic of questions of a semantically interpreted formalized language is introduced.This paper was presented at the symposium Erotetic Logic. A Dialogue organized by the Center for the Philosophy and History of Science of Boston University (February, 1994) and prepared during my stay at the Department of Philosophy, University of California, Riverside as a Fulbright grantee.I would like to thank Professors David Harrah and Sylvain Bromberger for valuable suggestions and comments.     

Axiomatic extensions of the constructive logic with strong negation and the disjunction property

We study axiomatic extensions of the propositional constructive logic with strong negation having the disjunction property in terms of corresponding to them varieties of Nelson algebras. Any such varietyV is characterized by the property: (PQWC) ifA,B εV, thenA×B is a homomorphic image of some well-connected algebra ofV. We prove:

• each varietyV of Nelson algebras with PQWC lies in the fibre σ^?1(W) for some varietyW of Heyting algebras having PQWC,
• for any varietyW of Heyting algebras with PQWC the least and the greatest varieties in σ^?1(W) have PQWC,
• there exist varietiesW of Heyting algebras having PQWC such that σ^?1(W) contains infinitely many varieties (of Nelson algebras) with PQWC.

     

Changes in anaclitic–introjective personality dimensions,outcomes and psychoanalytic technique: a multi-case study

This study investigates changes in latent mental structures along the anaclitic and introjective dimensions in relation to outcomes in 14 cases of publicly financed psychoanalysis. The method of prototype matching was adapted for personality assessment, and multiple outcome measures were applied. For the anaclitic cases, symptom reduction was accompanied by more mature integration of anaclitic and introjective personality dimensions, while the introjective cases showed symptom reduction without such improvement. This could indicate that sustainable change in latent mental structures is more difficult to achieve in introjective than in anaclitic patients. Further research is needed to validate these preliminary results.     

The Potential Dual Use of Online Pharmacies

The technological advances of the 20th century resulted in the creation of the Internet and its introduction into everyday life on a global scale. The Internet provides access to information and the sale and purchase of goods. Medications are also subject to trade. Their sale is conducted by online pharmacies and their global turnover amounts to hundreds of billions of dollars. Medications ordered over the Internet are sent by mail all over the world. Considering the events of recent years, we cannot exclude the risk of a terrorist attack through online pharmacies. Terrorists can establish such companies, legally or illegally, or acquire ones already existing. Parcels, which are highly trusted by the customers of online pharmacies, can, for example, be contaminated with dangerous materials. The sale of online medications in the international system is potentially dangerous and requires international regulation.