The principle of excluded middle in quantum logic

The principle of excluded middle is the logical interpretation of the law V A v in an orthocomplemented lattice and, hence, in the lattice of the subspaces of a Hilbert space which correspond to quantum mechanical propositions. We use the dialogic approach to logic in order to show that, in addition to the already established laws of effective quantum logic, the principle of excluded middle can also be founded. The dialogic approach is based on the very conditions under which propositions can be confirmed by measurements. From the fact that the principle of excluded middle can be confirmed for elementary propositions which are proved by quantum mechanical measurements, we conclude that this principle is inherited by all finite compound propositions. For this proof it is essential that, in the dialog-game about a connective, a finite confirmation strategy for the mutual commensurability of the subpropositions is used.     

Does the law of excluded middle require bivalence?

Determining whether the law of excluded middle requires bivalence depends upon whether we are talking about sentences or propositions. If we are talking about sentences, neither side has a decisive case. If we are talking of propositions, there is a strong argument on the side of those who say the excluded middle does require bivalence. I argue that all challenges to this argument can be met.     

Intuitionistic modal logics incompatible with the law of the excluded middle

In this paper, intuitionistic modal logics which do not admit the law of the excluded middle are studied. The main result is that there exista a continuum of such logics.     

A cut-free gentzen-type system for the logic of the weak law of excluded middle

The logic of the weak law of excluded middleKC _p is obtained by adding the formula A A as an axiom scheme to Heyting's intuitionistic logicH _p . A cut-free sequent calculus for this logic is given. As the consequences of the cut-elimination theorem, we get the decidability of the propositional part of this calculus, its separability, equality of the negationless fragments ofKC _p andH _p , interpolation theorems and so on. From the proof-theoretical point of view, the formulation presented in this paper makes clearer the relations betweenKC _p ,H _p , and the classical logic. In the end, an interpretation of classical propositional logic in the propositional part ofKC _p is given.     

The excluded player in coalition formation

Coalition research generally assumes that people strive to maximize their share of the coalition payoff and that they exclude others from joining a coalition if these others are not needed to obtain the coalition payoff. In two experiments, the authors show that this view is too narrow and that willingness to include such others is dependent on the extent to which people feel that exclusion affects the payoff of the excluded player. This finding was moderated by social value orientations. Proselfs were not affected by the consequences for the excluded players. Prosocials were less willing to exclude others the more harmful were the consequences of exclusion. Results are related to research on social exclusion, the do-no-harm principle, and social value orientations.     

规范市场:道德建设的必由之路

发展市场经济与道德建设具有内在的一致性。发展市场经济必须规范市场 ,而商品作为价值与使用价值的统一 ,它所具有的利己与利他的伦理二重性也必须在规范市场中得以实现 ;现实内涵发展着的为人民服务 ,既是干部为人民和人民为人民的双主体服务 ,也是利己与利他相统一的服务 ,这种双向服务也只能在规范市场中展开、完成。所以 ,规范市场是以达到利己与利他相统一为目的的道德建设的必由之路     

Being excluded by one means being excluded by all: Perceiving exclusion from inclusive others during one-person social exclusion

Although research has shown that social exclusion undermines well-being, past work has focused primarily on complete and unambiguous social exclusion in which all people in a situation exclude one individual. Might the presence of an inclusive other buffer individuals against the deleterious consequences of social exclusion? The present research investigates a novel situation, one-person exclusion, in which one person includes while another excludes. Participants played a virtual ball-tossing game in which they experienced two-person exclusion, one-person exclusion, or inclusion. Inclusive others did not buffer against the consequences of exclusion; experiencing one-person exclusion (vs. inclusion) led to perceived exclusion and lessened belongingness, similar to two-person exclusion. Moreover, instead of perceiving includers as a form of support, paradoxically, participants inaccurately believed that inclusive others had engaged in exclusion. These findings suggest that one-person exclusion is sufficient to elicit negative outcomes and that inclusive bystanders may be perceived as part of the exclusion.     

Program Extraction from Normalization Proofs

This paper describes formalizations of Tait's normalization proof for the simply typed λ-calculus in the proof assistants Minlog, Coq and Isabelle/HOL. From the formal proofs programs are machine-extracted that implement variants of the well-known normalization-by-evaluation algorithm. The case study is used to test and compare the program extraction machineries of the three proof assistants in a non-trivial setting.     

Patterns of language impairment and behaviour in boys excluded from school

Background. High levels of behaviour problems are found in children with language impairments, but less is known about the level and nature of language impairment in children with severe behavioural problems. In particular, previous data suggest that at primary age, receptive impairments are more closely related to behaviour problems, whereas expressive language has a closer link at a later age. Aims. The study assessed expressive and receptive language problems in boys excluded from primary and secondary schools, to investigate the extent of impairment, the pattern of relations between age, receptive and expressive language, and relations with different aspects of behaviour. Sample. Nineteen boys (8–16 years of age) who had been excluded from school and 19 non‐excluded controls matched for age and school participated. Method. The sample was given assessments of: receptive language from the British Picture Vocabulary Scale (BPVS), and Wechsler Objective Language Dimensions (WOLD); expressive‐language evaluations from the Wechsler Intelligence Scale for Children (WISC); auditory working memory evaluations from the Clinical Evaluation of Language Fundamentals (CELF); verbal reasoning (from the WISC); and non‐verbal IQ assessments Raven's matrices. Teachers completed behaviour ratings using the Strengths and Difficulties Questionnaire (SDQ). Results. Excluded boys were significantly poorer than controls on expressive measures but similar on receptive language and non‐verbal IQ. Boys excluded from primary school were poorer than controls on auditory working memory. Expressive problems were linked with high levels of emotional symptoms. Conclusion. Many of the excluded boys had previously unidentified language problems, supporting the need for early recognition and assessment of language in boys with behaviour problems. Expressive problems in particular may be a risk factor.     

Intuitionistic Games: Determinacy,Completeness, and Normalization

We investigate a simple game paradigm for intuitionistic logic, inspired by Wajsberg’s implicit inhabitation algorithm and Beth tableaux. The principal idea is that one player,  ?ros, is trying to construct a proof in normal form (positions in the game represent his progress in proof construction) while his opponent, ?phrodite,  attempts to build a counter-model (positions or plays can be seen as states in a Kripke model). The determinacy of the game (a proof-construction and a model-construction game in one) implies therefore both completeness and semantic cut-elimination.