Primal infon logic with conjunctions as sets

Primal infon logic was proposed by Gurevich and Neeman as an efficient yet expressive logic for policy and trust management. It is a propositional multimodal subintuitionistic logic decidable in linear time. However in that logic the principle of the replacement of equivalents fails. For example, (x ∧ y) → z does not entail (y ∧ x) → z, and similarly w → ((x ∧ y) ∧ z) does not entail w → (x ∧ (y ∧ z)). Imposing the full principle of the replacement of equivalents leads to an NP-hard logic according to a recent result of Beklemishev and Prokhorov. In this paper we suggest a way to regain the part of this principle restricted to conjunction: We introduce a version of propositional primal logic that treats conjunctions as sets, and show that the derivation problem for this logic can be decided in linear expected time and quadratic worst-case time. © 2014 IFIP International Federation for Information Processing

Primal logic of information

Primal logic arose in access control; it has a remarkably efficient (linear time) decision procedure for its entailment problem. But primal logic is a general logic of information. In the realm of arbitrary items of information (infons), conjunction, disjunction, and implication may seem to correspond (set-theoretically) to union, intersection, and relative complementation. But, while infons are closed under union, they are not closed under intersection or relative complementation. It turns out that there is a systematic transformation of propositional intuitionistic calculi to the original (propositional) primal calculi; we call it Flatting. We extend Flatting to quantifier rules, obtaining arguably the right quantified primal logic, QPL. The QPL entailment problem is exponential-time complete, but it is polynomial-time complete in the case, of importance to applications (at least to access control), where the number of quantifiers is bounded

Lewis meets Brouwer: constructive strict implication

C. I. Lewis invented modern modal logic as a theory of "strict implication". Over the classical propositional calculus one can as well work with the unary box connective. Intuitionistically, however, the strict implication has greater expressive power than the box and allows to make distinctions invisible in the ordinary syntax. In particular, the logic determined by the most popular semantics of intuitionistic K becomes a proper extension of the minimal normal logic of the binary connective. Even an extension of this minimal logic with the "strength" axiom, classically near-trivial, preserves the distinction between the binary and the unary setting. In fact, this distinction and the strong constructive strict implication itself has been also discovered by the functional programming community in their study of "arrows" as contrasted with "idioms". Our particular focus is on arithmetical interpretations of the intuitionistic strict implication in terms of preservativity in extensions of Heyting's Arithmetic.Comment: Our invited contribution to the collection "L.E.J. Brouwer, 50 years later

Pseudo-contractions as Gentle Repairs

Updating a knowledge base to remove an unwanted consequence is a challenging task. Some of the original sentences must be either deleted or weakened in such a way that the sentence to be removed is no longer entailed by the resulting set. On the other hand, it is desirable that the existing knowledge be preserved as much as possible, minimising the loss of information. Several approaches to this problem can be found in the literature. In particular, when the knowledge is represented by an ontology, two different families of frameworks have been developed in the literature in the past decades with numerous ideas in common but with little interaction between the communities: applications of AGM-like Belief Change and justification-based Ontology Repair. In this paper, we investigate the relationship between pseudo-contraction operations and gentle repairs. Both aim to avoid the complete deletion of sentences when replacing them with weaker versions is enough to prevent the entailment of the unwanted formula. We show the correspondence between concepts on both sides and investigate under which conditions they are equivalent. Furthermore, we propose a unified notation for the two approaches, which might contribute to the integration of the two areas

Surface attraction: hyphological encounters with the films of David Lynch.

How does one turn a cinematic passion into an academic thesis? This is the question that runs through my work, which is both a labour of love and a series of love letters. Does one, can one, tell the truth about one's love object? Written in solitude about the darkened passions of the cinema, and the commodified reenactment via DVD and video, it seeks to locate this body of work, organized under the signifier David Lynch, within a broader cultural history of film and art, rather than, as so many chronologically based studies have done, to assess the individual films and then collectively to remark upon the auteur's signature. Instead, it seeks to experience again, or anew, the ontological strangeness of film within the saturated market place, and observe how, in this body of work, the normative framework of the North American film industry is disturbed from inside by a practice which explores and critically examines the creative potential of the medium within the constraints of the capitalist mode of production and consumption. Taking Roland Barthes' neologism of the theory of the text as a hyphology as its means of organization, the thesis presents a series of chapters which consider separate concepts or ideas about these films which, although appearing freestanding, come together in the final chapter in this web of engagement with Lynch's cinema and critical theory. In the final analysis, the work reflects upon a range of approaches to its subject to conclude that the solitary, or seemingly isolated, experience of film is itself socially, culturally and politically important and tells us a great deal about contemporary subjectivity

Cross-cultural and tribal-centred politics in American Indian studies: assessing a current split in American Indian literary scholarship and re-interpreting Leslie Marmon Silko's Ceremony and Louise Erdrich's Tracks

The thesis examines the current split in American Indian literary studies between cross-cultural and tribal-centred schools of criticism through analyses of Arnold Krupat's, Louis Owens's and Gerald Vizenor's scholarship, on one side, and Elizabeth Cook-Lynn's and Craig Womack's critical work, on the other. The conflicting critical positions, despite their growing importance, have not received a consistent analysis in the critical discourse. The implications of this controversy for the future of American Indian studies and for the ways in which American Indian literature may be studied and taught have not been examined in depth. Particularly, there is little recognition of the validity of tribal-centred contributions to the field. The research seeks to address such gaps in the current scholarship: it develops a synoptic discussion of the opposing critical positions, assesses their strengths and drawbacks, and proposes a possible resolution of the controversy. The thesis argues that crosscultural scholarship (in conjunction with postcolonial and postmodern theory) has contributed importantly to the understanding of discursive hybridity as a vital aspect of American Indian existence, writing and anticolonial resistance. Yet, cross-cultural criticism has sidelined questions regarding tribal sovereignty discourse and tribal centred identity politics. Tribal-centred scholarship is making an important, and still ignored and misunderstood contribution to American Indian studies because it assists the understanding of these two important categories in American Indian experience and decolonisation. Assessing contributions and omissions of either critical position, the research posits that the current critical split could and should be negotiated to enable a more accurate and comprehensive reading of the political discourses that shape American Indian experience, anticolonial struggles and writing. The research illustrates the controversy and its potential mediation through a re-interpretation of two "representative" American Indian novels: Leslie Marmon Silko's Ceremony and Louise Erdrich's Tracks. Part One of the research - chapters one, two and three - analyses the debate, while Part Two - chapters four and five - re-reads Ceremony and Tracks

Theatre, an empty space : a thought performance after Gilles Deleuze.

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN037625 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The poetics of the non-verbal : code and performance in Jean Genet's theatre

This is an extensive study of the non-verbal in Genet's dramaturgy. Non-verbal forms constitute the plural, fragmented sum of theatrical possibility. Rhythms, movements, colours and shapes highlight the ritualised form of words and actions on and off stage. In Part One I define my understanding of Genet's theory of representation, and show how this theory informs his use of the non-verbal. On the one hand the discursive limits of Genet's reality forefront closure. On the other, within this closure an absence of transcendental meaning enables signs to be reconfigured and accorded a plurality of signification. A wealth of non-verbal scenic elements is codified and made to signify. But an antagonism between the triumphant liberation from inherent meaning and the inevitable falsity of representation underlies all Genet's theatre. Genet's reconfiguration involves transubstantiation, not substitution. It adds a supplementary layer of falsity to the sign. The co-presence of multiple layers of artifice effects a duality of belief and disbelief in the spectator, redefining the notion of theatricality. Non-verbal forms are of existential as well as theatrical import. Falsity is omnipresent. Genet thus destabilises and redramatises security, possession and identity. Part Two develops and illustrates the notion of the non-verbal elaborated in Part One through a predominantly stylistic study. I illustrate how performance on Genet's stage is a surface made of ritualised gestures and words, devoid of substance. Through constant polyphonic shifting characterisation is fragmented and unity of voice is denied. Central acoustic matrices are expanded forming homogenous blocks of repeated words, phonemes, stresses and prosodies. These blocks are juxtaposed with other rhythms creating chains of antagonistic structures that fracture traditional diegesis. Actors' gestures, tone, pitch, tempo and costume display a hybrid heterogeneity of styles which abolishes the monolithism of identity. The horizontal, vertical and diagonal lines constituting the set create a lattice network that fills a hypothetical vide with Genet's panoramic definition of reality. All these material signifiers resist metaphorical globalisation into themes or characters. They subsequently afford an opacity that fractures action into immediate acoustic and visual effects, and underscores form as surface detached from the oppressiveness of substance. And yet the absence of substance merely underscores the falsity of Genet's success. My concluding comments state that material, non-verbal artifice is freed from essentialist signification. It is therefore mobile, not static. The plural and liberated nature of the non-verbal enables Genet's singularity to be expressed, and in turn allows for the singularity of the spectator

Modernity, Selfhood, and the Demonic: Anthropological Perspectives on "Chaos Magick" in the United Kingdom

The thesis is based upon fieldwork conducted in London (between 1997 - 2001) amongst the practitioners of "Chaos magick" -a form of magical practice which appeared in United Kingdom during the late 1970's as part of the wider neo-pagan and magical subculture. Chaos magicians utilise trance states as means of attaining an unmediated experience of the inchoate and indeterministic ground of being known as "Chaos". Within trance, Chaos magicians believe that they are able to transform both their perception and the substance of the world by magically reshaping the Chaos force in accordance with their own desires. Merged with the therapeutics of spirit possession, such practices also aim to render visible and subject to control the "demons" of the psyche - conceived of as the socially-inculcated fears, desires and patterns of behaviour which "possess" the magician's persona. I show that, for Chaos magicians, the demonic represents a highly ambivalent category through which the equally ambivalent and uncertain experience of modernity is mirrored and made explicable. Possession by alien and demonic powers may also be positively valued as a source of "creativity" and self-empowerment, allowing practitioners to construct contextual and contingent narratives of the self - narratives commensurable with the uncertainties and insecurities of their daily lives. I also demonstrate that the broadly therapeutic goals of Chaos magick are indented within a set of discursive practices that shape practitioners' sense of selfhood to the social, economic and ideological requirements of late modernity. As a consequence, the thesis challenges prior anthropological conceptions of the contemporary magical subculture as a subaltern discourse engaged in resisting the rationalising and alienating effects of modem consumer capitalism; in doing so, the thesis demonstrates that this subculture is neither "Irrational" nor "pre-modern", but does in fact recapitulate many of the core values and assumptions of modernity