Proving Determinacy of the PharOS Real-Time Operating System

International audienceExecutions in the PharOS real-time system are deterministic in the sense that the sequence of local states for every process is independent of the order in which processes are scheduled. The essential ingredient for achieving this property is that a temporal window of execution is associated with every instruction. Messages become visible to receiving processes only after the time window of the sending message has elapsed. We present a high-level model of PharOS in TLA+ and formally state and prove determinacy using the TLA+ Proof System

Encoding TLA+ into unsorted and many-sorted first-order logic

International audienceTLA+ is a specification language designed for the verification of concurrent and distributed algorithms and systems. We present an encoding of a non-temporal fragment of TLA+ into (unsorted) first-order logic and many-sorted first-order logic, the input languages of first-order automated theorem provers. The non-temporal subset of TLA+ is based on untyped set theory and includes functions, arithmetic expressions, and Hilbert's choice operator. The translation, based on encoding techniques such as boolification, injection of unsorted expressions into sorted languages, term rewriting, and abstraction, is the core component of a back-end prover based on first-order theorem provers and SMT solvers for the TLA+ Proof System

Ways, Proofs, and the Intelligibility of God: Thomas Aquinas’s Five Ways as Leading into the Intelligibility of an Existing God

There is some question about how to understand Thomas Aquinas’s five ways of demonstrating that God exists. Often philosophers and theologians portray Thomas as a strict Aristotelian rationalist with a strong emphasis on syllogistic epistemology. Against this view a competing existential, metaphysical, and theological understanding of the five ways has been gradually gaining ground, beginning in the early 20th century, due to the work of existential Thomists such as Etienne Gilson, Jacques Maritain, and Joseph Owen. This understanding has been expanded more recently in the work of John Wippel and others. The rise of the existential view has led to the question of whether Thomas meant for the five ways to be strict epistemic proofs or whether they are instead a way to talk about God that presumes faith and metaphysics. This dissertation will present the five ways within a full range of contextual issues. These include epistemic, metaphysical, theological, historical, anthropological, and literary contexts. When all contexts are taken into account, the conclusion is that the ways are primarily metaphysical-theological yet they produce epistemic scientia resulting in knowledge that God exists. The five ways are primarily examples of how to properly talk about God in light of revelation, metaphysics, and the proper mode of the human knower, yet also syllogistic demonstrations that God exists. Such an understanding holds the potential to answer some of the arguments of the critics of the five ways, such as Anthony Kenny. Thomas shows himself to be thoroughly grounded in both faith and reason in such a way that there is a healthy balance between them that does proper justice to both faith and reason. The significance of this dissertation comes in two places. The first is the weaving together of a wide range of contextual interpretive factors that are not usually applied specifically and explicitly to the five ways in one unified work. The second is in the unification of the epistemic and theological interpretations of the ways, under a synthesis that accounts for both manners of interpreting the five ways

Love For God And Earth: Ecospirituality In The Theologies Of Sallie Mcfague And Leonardo Boff

This dissertation examines the theologies of North American Ecofeminist Sallie McFague and Latin American liberation theologian Leonardo Boff in order to answer the question - What are the features of a Christian spirituality capable of helping people to clear vision, transformation and hope in this time of socio-ecological crisis? In the sixth chapter I also briefly engage the work of Carmelite contemplative Constance FitzGerald, as she both reinforces and deepens the theologians\u27 answer to the above question. The dissertation begins with a short explanation of the interlocking ecological and social crises, and offers a basic understanding of Christian spirituality as powerfully transformative of human assumptions and actions in the world. In Chapter One I argue that a study of McFague\u27s metaphorical theology indicates that authentic Christian spirituality must challenge false social constructions. Investigating McFague\u27s model of the world as God\u27s body, Chapter Two then illustrates how to live by a spirituality that loves God while caring deeply for the needs of the world. In Chapters Three and Four I show that an examination of Boff\u27s theological corpus elucidates how people can and must live in the experience of God through their every experience of the world. In this way, his theology explicates why and how God must be experienced for individual and collective fulfillment, as well as for producing a marked global and historical transformation. After summarizing and evaluating, in chapter five, the theologians\u27 contributions to contemporary Christian spirituality, chapter six briefly explores FitzGerald\u27s call to a contemplative yielding to God in this time of crisis so that God\u27s own vision and imagination may transform human consciousness. Thus, with all three authors I indicate that Christian spirituality is capable of producing clear vision, transformation and hope inasmuch as (1) it challenges false social constructions; (2) orients people to loving God while caring for the wellbeing of the world; (3) shows them how to experience God\u27s presence in their lives and understands the power of this experience to transform the course of history; and, most radically, (4) teaches people to yield to God so that God\u27s own vision for the future may arise in human consciousness. Such a Christian spirituality is well equipped for birthing a new humanity through the present socio-ecological crisis

Schooling the imagination: a practical theology of public education

This dissertation develops a public practical theology of education. It argues that education is a practice that “schools the imagination,” forming individuals and communities to operate within social imaginaries that have been shaped by a latent, anti-material, and individualistic worldview. This project aims to show that public education is a viable site for theological reflection and that the results of that reflection can generate proposals for the transformation of both religion and education. It considers how the American social imaginary is maintained by educational practices and the ways these practices influence conceptions of knowledge and human purpose. The assumption is that the shaping influence of the imaginary is not manifested so much in the content of school curricula, but tacitly exists in pedagogical processes and the explicit and implicit goals of the US educational enterprise. Using a qualitative and quantitative mixed-method approach, the project develops the construct of conscientização natal, a pedagogy of birth with utopian anthropological dimensions. Grace Jantzen’s theology and philosophy of religion and the liberative pedagogical insights of Paulo Freire are central to the constructive work. Jantzen and Freire provide a way to interpret the telos and practice of American public education with their respective analyses of “necrophilic imagination” and “objectivizing worldviews.” Additional insights are drawn from educational sociology and history, as well as Pierre Bourdieu’s theory of practice and Cornelius Castoriadis’ concept of the social imaginary. The dissertation begins by developing a theology of education, doing so with practical theological methods informed by liberation and public theologies. It proceeds to provide historical and cultural-sociological studies drawn from educational literature, amplified by a quantitative study of 125 survey participants on their understandings of the relationship between education and spirituality. The primary discoveries in these three studies are analyzed, then reflected upon theologically, yielding proposals for the transformation of practice and theory in both education and religion. For practical theologians, the project develops a robust understanding of practice that links patterns of action to social imaginaries, providing an example of how practical theology might consider issues of broad public concern

The theme(s) of the Joseph story: a literary analysis

Since the 1970s the application of narrative analysis to the Joseph Story has enriched its reading. But those who apply this method to the narrative produce significantly different results in terms of what its theme is. The aim of this thesis is to investigate the reasons for this and to articulate as objectively as possible the theme of the Joseph Story. Chapter One establishes the context of this investigation by evaluating the major narrative readings of the Joseph Story. It reveals that those who apply narrative methodologies to the story come to different conclusions about what its theme is. It notes that the different results could be due to different narrative approaches, the literary context of the narrative, and the complex nature of the text itself. We choose Humphreys, Longacre, and Turner as our dialogue partners because they represent different narrative methods of reading the Joseph Story. The reference terms `narrative criticism' and `theme' are then defined. Chapter Two argues that the way to overcome the confusion concerning the theme (s) of the Joseph Story is to use a methodology that addresses the limitations of the literary approaches applied to the narrative and takes note of the wider literary context of Genesis and the rich nature of the text. This chapter then proposes a narrative methodology of `triangulation' that comprises plot analysis, text-linguistics and poetics. Chapters three, four and five apply this methodology to the entire narrative in Genesis 37-50 via a detailed analysis of Genesis 37,44-45, and 49-50, the beginning, middle and end of the narrative, respectively. The motifs that emerge from our analysis are family breakdown, power, providence, blessing, and land. Chapter six concludes that each of these motifs is a key concern of the Joseph Story but none by itself adequately articulates the story's theme. It is the ecology of these motifs that enunciates the theme: God's providential work with and through Jacob's dysfunctional family, preserving it and blessing others

What Is 'Critical' About Critical Theory?

The idea of a critical theory has colonized the social consciousness of academia, and become an integral part of the pursuit of higher knowledge. Competing ideas have thereby become standard bearers in that critical theory acts as a measure of true understanding . The only problem, however, is that many of the distinct theories similarly answering to the description raise two related questions – namely, ‘what is a critical theory?’ and what is ‘critical’ about the ‘theory’ (or theories) in question? We explore the problematic connection between criteria and critique, and consider the critical theories of Derrida, Lyotard and Habermas via hermeneutics's conception of the circular relation between thought and language. The approach is performative in that the competing critical theories are interpreted as parts that form a complex whole, and are understood (questioned) with respect to each other. We argue that the critical issue between them is a normative conception of our practical and/or linguistic identities . The methodological approach to the circle therefore serves a critical function in that it is performed (enabled and directed) through the very idea(s) in question

General Average and Risk Management in Medieval and Early Modern Maritime Business

This open access book explores the history of risk management in medieval and early modern European maritime business, focusing particularly on 'General Average' – a mechanism by which extraordinary expenses regarding ship or cargo, incurred during a voyage to save the venture, are shared between all participants to protect equity. This volume traces the history of this risk management tool from its origins in the pre-Roman Mediterranean through to its use in the shipping sector today. Contributions range from the Islamic Mediterranean to the Low Countries, and taken together, provide a wide-ranging analysis of social, cultural, and political aspects of pre-modern maritime commerce in Europe