Equivalential logics (I)

The class of equivalential logics comprises all implicative logics in the sense of Rasiowa [9], Suszko's logicSCI and many Others. Roughly speaking, a logic is equivalential iff the greatest strict congruences in its matrices (models) are determined by polynomials. The present paper is the first part of the survey in which systematic investigations into this class of logics are undertaken. Using results given in [3] and general theorems from the theory of quasi-varieties of models [5] we give a characterization of all simpleC-matrices for any equivalential logicC (Theorem I.14). In corollaries we give necessary and sufficient conditions for the class of all simple models for a given equivalential logic to be closed under free products (Theorem I.18). Theorem I.17 can be generalized as follows:For any equivalential logic C, clauses (i), (iii)and (v),formulated in Th.I.17,are equivalent.     

S. A. Janovskaja

With the passing of S. A. Janovskaja, contemporary Soviet philosophy has lost one of its leading experts in logic and in combining creativity with survival.     

Epidemiology and psychopathology of epileptics in Bydgoszca Province registered between 1976 and 1980

In the years 1976-1980, the province of Bydgoszcz had a total of 2635 registered epileptics, or 0.37% of the entire population, over the age of 16. From these, 200 patients were randomly selected, and between 1983 and 1985 a complats clinical follow-up investigation was carried out. Among the most frequent mental disorders found were postparoxysmal twilight state (19.5%) and affective psychoses (11%), among the chronic disorders, dementia of varying intensity (26.5%). In contrast with previous investigations the present investigation made it possible to determine with precision the cause of epileptic attacks. The ratio was 61% to 31%.     

Partial Boolean algebras in a broader sense

The article deals with compatible families of Boolean algebras. We define the notion of a partial Boolean algebra in a broader sense (PBA(bs)) and then we show that there is a mutual correspondence between PBA(bs) and compatible families of Boolean algebras (Theorem (1.8)). We examine in detail the interdependence between PBA(bs) and the following classes: partial Boolean algebras in the sense of Kochen and Specker (§ 2), ortholattices (§ 3, § 5), and orthomodular posets (§ 4), respectively.     

Reduced products of logical matrices

The class Matr(C) of all matrices for a prepositional logic (, C) is investigated. The paper contains general results with no special reference to particular logics. The main theorem (Th. (5.1)) which gives the algebraic characterization of the class Matr(C) states the following. Assume C to be the consequence operation on a prepositional language induced by a class K of matrices. Let m be a regular cardinal not less than the cardinality of C. Then Matr (C) is the least class of matrices containing K and closed under m-reduced products, submatrices, matrix homomorphisms, and matrix homomorphic counter-images.     

A deduction theorem schema for deductive systems of propositional logics

We propose a new schema for the deduction theorem and prove that the deductive system S of a prepositional logic L fulfills the proposed schema if and only if there exists a finite set A(p, q) of propositional formulae involving only prepositional letters p and q such that A(p, p) L and p, A(p, q) _s q.     

Increasingly cautious sampling,not the black colouration of unpalatable prey,is used by fish in avoidance learning

Animal Cognition - The efficiency of aposematic colouration of prey is based on the innate bias or facilitation of avoidance learning of predators. In many toxic bufonids, larvae are uniformly...     

Medical or relational language? Problem and goal formulation in family therapy with adolescents conducted in a psychiatric outpatient setting

The constructionist view assumes that therapy participants' maps of understanding depend on the institutional context and their personal perspectives. The purpose of this study was to investigate the initial maps of difficulties reported by family members starting family therapy. 106 families that were referred to a psychiatric institution for outpatient family therapy were asked open-ended questions regarding the context of the referral, and goal and problem formulation for the therapy. The data were analysed via the consensual qualitative research-modified (CQR-M) method, and comparisons between groups were performed. The obtained results show a diversity of perspectives. Of interest was the predominance of medical language in describing the problem and relational language in describing the goal of therapy. An analysis of differences between mothers, fathers, adolescent patient and their siblings was also performed. The findings highlight the complexity of notions that families start family therapy with and may help therapists navigate through the therapeutic contract formulation process.