Qualitative coalitional games (QCGs) were introduced as abstract formal models of goal-oriented cooperative systems. A QCG is a game in which each agent is assumed to have some goal to achieve, and in which agents must typically cooperate with others in order to satisfy their goals. In this paper, we show how it is possible to reason about QCGs using Coalition Logic (CL), a formalism intended to facilitate reasoning about coalitional powers in game-like multiagent systems. We introduce a correspondence relation (...) between QCGs and interpretations for CL, which defines the circumstances under which a CL interpretation correctly characterises a QCG. The complexity of deciding correspondence between QCGs and interpretations for CL is shown to vary from being tractable up to Πp 2-complete, depending on the representation chosen for the QCG and interpretation. We then show how various properties and solution concepts of QCGs can be characterised as CL formula schemes. The ideas are illustrated via a detailed worked example, in which we demonstrate how a model checker can be deployed to investigate whether a particular system has the properties in question. (shrink)

§ 1. Introduction. Perhaps the most surprising recent development in complexity theory is the discovery that the class NP can be characterized using a form of randomized proof checker that only examines a constant number of bits of the “proof” that a string is in a language [6, 5, 31, 3, 4]. More specifically, writing ∣x∣ for the length of a string x, a language L in the class NP of languages recognizable in Nondeterministic polynomial time is traditionally given by (...) a polynomial p and a polynomial-time predicate P such that a string x is in L iff there is some string y satisfying P, where ∣y∣ ≤ p. Intuitively, we can think of a string y as a possible proof that x ϵ L, with the predicate P some kind of proof checker that distinguishes good proofs from bad ones. A string x is therefore in a language L ϵ NP if there is a short proof that x ϵ L, and not in L otherwise. The surprising discovery is that the deterministic proof checker that reads the entire input and proof can be replaced by a probabilistic verifier that on input x and possible proof y, where y is presented in a certain way, flips at most O coins and reads at most a constant number of bits of x and y. Obviously, a probabilistic verifier that does not read the whole proof will sometimes make mistakes. However, the surprising and essentially non-intuitive mathematical fact is that for each language L in NP, it is possible to find a polynomial q and verifier V flipping a logarithmic number of coins and reading a constant number of bits such that, for any x ϵ L, there exists y with ∣y∣ ≤ q and with V accepting with probability 1 and, for x ∉ L, there is no y with ∣y∣ ≤ q and with V accepting with probability ≥ 1/4. This idea canalsobeextended to PSPACE [10, 9], using a game that alternates between two players instead of a proof presented by a “single player.”. (shrink)

Callimachus,ep. 1 Pfeiffer (= LIV Gow-Page =AP7.89) relates an anecdote about Pittacus: when consulted by a stranger from Atarneus who was wondering whether to marry a woman of his own social class or one of a higher status, he suggests the question is answered by the cries of the children playing with tops, τν κατ ｃαντν ἔλα. The chequered history of the transmission and interpretation of the poem is beset by a number of unfavourable or patronizing judgements which, I hope (...) to show, have their origin in a series of misunderstandings. The poem seems to lack the sharp point characteristic of epigrams, and indeed Gow-Page go so far as to pronounce that it ‘has no claim to be called an epigram at all’. We now have a number of valuable parallels for the unusual length of the piece, but grave doubts continue to be expressed about the Callimachean authorship of the poem. While Diogenes Laertius (henceforth referred to as ‘D.L.’), who quotes the poem in his life of Pittacus (1.79ff.), explicitly attributes it to καλλμαχοఁ ν τοῖఁ ’Epsilon;πιγρμμαఁιν, in P and PI there is no ascription at all: there our epigram has been mistakenly consigned to the ’ɛπιτμβια simply becauseAP7.81 (= Antipater XXXIV Gow-Page), on the Seven Sages, is followed by some fifty epigrams on them and other philosophers, all (save three) derived from D.L. In the Palatine ms. there survive traces of the questions raised by this poem, though—surprisingly—both Pfeiffer and Gow-Page fail to report them. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Attic Document Reliefs: Art and Politics in Ancient AthensWilliam C. WestCarol L. Lawton. Attic Document Reliefs: Art and Politics in Ancient Athens. Oxford: Clarendon Press, 1995. xxii 1 167 pp. 96 pls. Cloth, $100. (Oxford Monographs on Classical Archaeology)Although long recognized as a distinct genre, the reliefs on documents have not been collected comprehensively and studied for their own sake. They are set above the texts of honorary (...) decrees, alliances and documents concerning [End Page 465] foreign affairs, decrees concerning cults, accounts and inventories, public dedications, and other inscriptions. Previous work on the subject (Binnebössel 1932; Meyer 1989) sought to relate the reliefs to other genres of art. Lawton notes that the document relief is “the only genre of Greek art that explicitly and consistently refers to contemporary events in the political sphere” (4). The style of the sculpture of the reliefs is shown to be conservative, “following rather than setting the sculptural trends of their own day” (73).The aim of illustrating documents with reliefs seems to be the desire to highlight certain relations to the text (deities as representative of cities; heroes, personifications of Demos, Boule, and Demokratia; individuals honored set amid the appropriate divinities, etc.). Expenses for inscribing were sometimes shared, as by cities of the empire or by individuals who received honorary decrees, but the cost of inscribing probably also included the reliefs (23–24). They would have been commissioned by authority of the secretaries of the assembly (or other political group such as deme or tribe) in consultation with sculptors and masons. Thus the relief contributes to the artistic display, just as certain features of the layout of the text on the stone (stoichedon style, intentional use of vacat, chequer pattern) serve to articulate the elements of the text and create an attractive monument. Lawton asserts that most of the document reliefs had a votive function, as they were set up in sanctuaries (29).Lawton presents a catalogue of 187 reliefs, arranged in two parts (dated and undated) and listed in chronological order within each part. Each item is accompanied by a lemma giving its most accessible publication, location, measurements, iconographical description, and bibliography. Thus 62 are classified as dated and 125 as undated. Although they range from the middle of the fifth to the second half of the second century B.C., the overwhelming preponderance fall in the fifth and fourth centuries. Statistics make the point effectively: fifth century, 28 total (12 dated, 16 undated); fourth century, 148 total (46 dated, 102 undated). Five are classified “late 5th-early 4th century,” bringing the grand total to 181. Of the dated group in the fourth century, only 9 can be put after 323 and only 4 after 318/17. One might justifiably conclude that the document relief is a phenomenon of the classical period, continued occasionally after it.Lawton offers excellent analyses, with concise discussion of relevant interpretations, in terms of type of inscription, iconography, style, and chronology. Where problems in interpretation still persist, she is careful to note the probabilities.Possibly the earliest surviving document with a relief is the Miletos decree (no. 63 = IG I3 21), which is put by Meritt and others about 450 because it uses the three-bar sigma, but in the 420s by H.B. Mattingly. Lawton summarizes fairly the arguments for both datings but does not insist on either. Rather, she notes the frequency of document reliefs from the 420s onward.IG I3 68 (no. 1), on the collection of tribute, is presented as the earliest securely dated inscription. Perhaps here the case is stated too positively, as the date 426/25 depends on the identification of the proposer Kleonymos with the man [End Page 466] who proposed a decree favoring Methone in the first prytany of that year (Meiggs and Lewis, no. 68, p. 188). Hence the date is probable, rather than certain. Secure dates for several decrees of the fourth century come from the name of the archon in the heading, but in cases where insufficient text is preserved for certainty (as in IG II2 133, no. 30) it should be noted that the stoichedon pattern provides... (shrink)

Checking is one of the most common compulsive actions performed by patients with Obsessive- compulsive disorder (OCD) (APA, 2013; Abramowitz, McKay, Taylor, 2008). Incessant checking is undeniably problematic from a practical point of view. But what is epistemically wrong with checking again (and again)? The starting assumption for this paper is that establishing what goes wrong when individuals check their stove ten times in a row requires understanding the nature of the doxastic attitude that compulsive re-checkers are in, as they (...) go back to perform another check. Does the re-checker know that the stove is off, and is thus looking for more of what she already has? Or is she an inquirer who repeatedly loses her knowledge and finds herself inquiring again and again into the same question? In this paper I present and discuss what I see as the three main hypotheses currently available on the market, and I suggest a refinement. (shrink)

Checking the equivalence of two Boolean functions, or combinational circuits modeled as Boolean functions, is often desired when reliable and correct hardware components are required. The most common approaches to equivalence checking are based on simulation and model checking, which are constrained due to the popular memory and state explosion problems. Furthermore, such tools are often not user-friendly, thereby making it tedious to check the equivalence of large formulas or circuits. An alternative is to use mathematical tools, called interactive theorem (...) provers, to prove the equivalence of two circuits; however, this requires human effort and expertise to write multiple output functions and carry out interactive proof of their equivalence. In this paper, we define two simple, one formal and the other informal, gate-level hardware description languages, design and develop a formal automatic combinational circuit equivalence checker tool, and test and evaluate our tool. The tool CoCEC is based on human-assisted theorem prover Coq, yet it checks the equivalence of circuit descriptions purely automatically through a human-friendly user interface. It either returns a machine-readable proof of circuits’ equivalence or a counterexample of their inequality. The interface enables users to enter or load two circuit descriptions written in an easy and natural style. It automatically proves, in few seconds, the equivalence of circuits with as many as 45 variables. CoCEC has a mathematical foundation, and it is reliable, quick, and easy to use. The tool is intended to be used by digital logic circuit designers, logicians, students, and faculty during the digital logic design course. (shrink)

Definition of the problem Digital health technologies have gained significant importance in recent years. These technologies include symptom checker apps which use algorithms or artificial intelligence to provide users with analyses and recommendations based on their symptom input. Despite their widespread recognition, research shows mixed results regarding the accuracy of these apps, thus, limiting their current utility. The interdisciplinary CHECK.APP project examined the ethical, legal, and social aspects associated with symptom checker apps. Arguments The resulting recommendations presented here are directed (...) towards various stakeholders, including users, physicians, developers, and public institutions. It is crucial to adopt a critical stance towards the use of symptom checker apps, promote health literacy and eHealth literacy, and ensure transparency regarding the data basis and user experiences. Moreover, there is a need for reliable and independent information sources that allow users and physicians to stay informed about current developments in the digitalization of healthcare. At the same time, developers are encouraged to follow clear guidelines on transparency, quality assurance, and accessibility. Additionally, policymakers are recommended to ensure the voluntary use of symptom checker apps and to create conditions that strengthen the health literacy of the population. Conclusion The recommendations presented here outline how symptom checker apps can be used responsibly to maximize potential benefits and minimize risks. (shrink)

Definition of the problem Digital health technologies have gained significant importance in recent years. These technologies include symptom checker apps which use algorithms or artificial intelligence to provide users with analyses and recommendations based on their symptom input. Despite their widespread recognition, research shows mixed results regarding the accuracy of these apps, thus, limiting their current utility. The interdisciplinary CHECK.APP project examined the ethical, legal, and social aspects associated with symptom checker apps. Arguments The resulting recommendations presented here are directed (...) towards various stakeholders, including users, physicians, developers, and public institutions. It is crucial to adopt a critical stance towards the use of symptom checker apps, promote health literacy and eHealth literacy, and ensure transparency regarding the data basis and user experiences. Moreover, there is a need for reliable and independent information sources that allow users and physicians to stay informed about current developments in the digitalization of healthcare. At the same time, developers are encouraged to follow clear guidelines on transparency, quality assurance, and accessibility. Additionally, policymakers are recommended to ensure the voluntary use of symptom checker apps and to create conditions that strengthen the health literacy of the population. Conclusion The recommendations presented here outline how symptom checker apps can be used responsibly to maximize potential benefits and minimize risks. (shrink)

I introduce some distinctions concerning depiction and show that the checker-shadow phenomenon is not an illusion of the kind it is claimed to be. This might also help to think more clearly about other ‘illusory’ phenomena.

One of the predominant debates in AI Ethics is the worry and necessity to create fair, transparent and accountable algorithms that do not perpetuate current social inequities. I offer a critical analysis of Reuben Binns’s argument in which he suggests using public reason to address the potential bias of the outcomes of machine learning algorithms. In contrast to him, I argue that ultimately what is needed is not public reason per se, but an audit of the implicit moral assumptions of (...) societies within which algorithms are built and applied. Public justification is appealing since it offers us the possibility to align the decision-making outcomes of the algorithm with the core moral values of stakeholders within a constitutional democratic society. My concern is that the common moral principles that form the foundation of public reason are not necessarily neutral, as they still express specific moral ideals and normative standards even if there is moral agreement by society as a whole, or among different stakeholders within society. Appealing to such normative standards may thus still lead to algorithmic outcomes being biased as common moral values may very well still be discriminatory even though they are formed from a consensus, and even if public reason is applied as a kind of filter for potential algorithmic outcomes. Hence, I argue that these implicit moral norms within society that we take as a given in public reasoning, need to be audited from generation to generation in order to effectively mitigate potential algorithmic bias. (shrink)

Context: Public universities in South Africa are currently facing the challenge of decolonising knowledge. This change requires a review of curriculums, as well as teaching and learning with the goal of embracing the epistemology of the learners, addressing issues such as social justice and transformation. Problem: Human communication is subject to several perceptual errors in both listening and seeing, which challenges the success of the communication in the education system. The ability of the teacher and the learners to effectively communicate (...) with one another is a factor for the success of each reaching their goals. The teacher imparts her knowledge in the classroom, but according to von Foerster, “[i]t is the listener, not the speaker, who determines the meaning of an utterance,” for the listener contextualises this information based on her own past lived experience. Thus, the student’s epistemology and her expression of her understanding is integral in the classroom context and should be actively included into the education system. Method: I present a cybernetic approach to the teacher-learner system, challenging traditional ideas about the role of each actor within the system, with special attention given to Pask’s conversation theory. Results: Early empirical findings suggest that a conversational contextual approach results in higher student involvement and better memory retention among the learners. Conversational approaches that are epistemologically inclusive diffuse social problems where the student groups require their individual worldviews to be reflected within the curriculum. This reduces the friction of competing epistemologies within the education system, moving toward a co-created contextually-driven knowledge system. Implications: Many educators would like deeper engagement from their learners but have not found a way to successfully engage the student group. A cybernetic approach is one method that can be adopted to remedy this. This is particularly useful in contexts where there is cultural diversity and impending social change. Constructivist content: I address von Glasersfeld’s points on human cognition, linking it to Austin’s speech acts. (shrink)

The reflections put forward in this text concern the clinical and practical difficulties posed by the existence of patients in PVS, and the essential ethical issues raised, combining these ethical questions with practical and theoretical experience.Section 1 presents the methodology of the ethical reflection as we see it.Section 2 describes the clinical condition of patients in PVS. Section 3 develops the ethical difficulties relative to PVS from the French point of view. Section 4 illustrates the relevance of debating the ethical (...) significance of such problematic situations, whilst defending a practical position based on a philosophical conviction. Section 5 points out the limits of ethical reflection in a biomedical context, and calls for reflection closer to the source of the problems described. For a comprehensive appraisal of biomedical rationality, the final section suggests combining the bioethical debates with traditional philosophical ethical reflection so as to get a clearer understanding of the real, if limited, relevance of these debates. (shrink)

Problem: How can radical constructivism gain wider recognition and acceptance? Method: Based on informal direct observation of other social and intellectual movements, the social and psychological dynamics and organizational imperatives of radical constructivism as an intellectual movement are discussed. Results: Various means of structuring the movement in order to gain wider acceptance are proposed. Implications: We hope that the paper has value in helping the radical constructivism movement evaluate where it has been and where it might go in terms of (...) wider social recognition and acceptance. (shrink)

We report a series of experiments in which subjects were required to make spatial discriminations about naturally obtained images, as follows. Subjects were shown two natural images on a computer screen, side by side and for a period of 500 ms. Subjects were then shown, on a separate part of the computer screen, a small patch of one of the images selected at random. Subjects were required to decide which of the two full images the patch comes from, and whereabouts (...) in that image it is taken from. They indicated their response by clicking the mouse cursor at the appropriate point on the screen. -/- The proportion of trials on which the subjects selected the correct image and the accuracy of the spatial position of their correct responses were calculated. These two measures independently indicate the general discriminability of the two image sets, and the extent to which the spatial layout of the image has been perceived. By comparing response accuracy for images that are from different sets (such as mountain or town scenes) with response accuracy when the two images are from the same set it is possible to establish the image properties that underlie coarse scene apprehension. By using sets of images that are perhaps best described as being natural textures (such as patterns of foliage or rock surface) it is possible to measure the extent to which texture is processed spatially. Our results are interpreted in the light of statistical differences between the image sets that we have used. (shrink)

The essay briefly review the intellectual bonds between Alchourrón and Bulygin and Italian legal thought. Alchourrón and Bulygin’s seminal work is widely read in Italy; and by now is considered essential groundwork by a growing generation of young legal scholars.