Weighted, Circular and Semi-Algebraic Proofs

The author studies the higher-order rewrite/equational proof systems obtained by adding the simply typed lambda calculus to algebraic rewrite/equational proof systems. He shows that if a many-sorted algebraic rewrite system has the Church-Rosser property, then the corresponding higher-order rewrite system which adds simply typed beta -reduction has the Church-Rossers property too. This result is relevant to parallel implementations of functional programming languages. The author also shows that provability in the higher-order equational proof system obtained by adding the simply typed beta and eta axions to some many-sorted algebraic proof system is effectively reducible to provability in that algebraic proof system. This effective reduction also establishes transformations between higher-order and algebraic equational proofs, which can be useful in automated deduction.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

We relate different approaches for proving the unsatisfiability of a system of real polynomial equations over Boolean variables. On the one hand, there are the static proof systems Sherali-Adams and sum-of-squares (a.k.a. Lasserre), which are based on linear and semi-definite programming relaxations. On the other hand, we consider polynomial calculus, which is a dynamic algebraic proof system that models Gröbner basis computations. Our first result is that sum-of-squares simulates polynomial calculus: any polynomial calculus refutation of degree d can be transformed into a sum-of-squares refutation of degree 2d and only polynomial increase in size. In contrast, our second result shows that this is not the case for Sherali-Adams: there are systems of polynomial equations that have polynomial calculus refutations of degree 3 and polynomial size, but require Sherali-Adams refutations of large degree and exponential size. A corollary of our first result is that the proof systems Positivstellensatz and Positivstellensatz Calculus, which have been separated over non-Boolean polynomials, simulate each other in the presence of Boolean axioms.

Complete SAT algorithms form an important part of the SAT literature. From a theoretical perspective, complete algorithms can be used as tools for studying the complexities of different proof systems. From a practical point of view, these algorithms form the basis for tackling SAT problems arising from real-world applications. The practicality of modern, complete SAT solvers undoubtedly contributes to the growing interest in the class of complete SAT algorithms. We review these algorithms in this chapter, including Davis-Putnum resolution, Stalmarck's algorithm, symbolic SAT solving, the DPLL algorithm, and modern clause-learning SAT solvers. We also discuss the issue of certifying the answers of modern complete SAT solvers.

Proof by consistency

Este artículo presenta un acercamiento teórico-discursivo al terrorismo internacional, y vincula las relaciones de poder hegemónicas que constituyen el orden internacional con la formación de los discursos globales sobre terrorismo internacional. Al entender el terrorismo internacional como una construcción discursiva, el documento analiza lo que supone etiquetar un determinado tipo de violencia como “terrorismo”, y la consecuente despolitización y securitización de esta violencia. Basándonos en estas reflexiones teóricas, se argumenta que el proceso de construcción discursiva de un determinado tipo de violencia política como terrorismo internacional estandarizado a nivel global depende de las relaciones de poder que constituyen la comunidad internacional, su identidad y su legitimidad; la razón de Estado, la razón de sistema y la razón de civilización. Al partir de este plantea - miento teórico, se propone que las formaciones histórico-discursivas globales sobre terrorismo internacional se han construido alrededor de un tipo de violencia política que representaba un desafío ideológico a estas relaciones de poder, su universalidad y su legitimidad. Finalmente, se presenta una genealogía de las formaciones discursivas estandarizadas que emergieron internacionalmente en la historia contemporánea y se deconstruyen estas formaciones a través del planteamiento teórico propuesto.

■ This qualitative case study explores the interrelations between play, literacy, and culture by closely examining the home play activities of Letitia, a 5-year-old Chinese Canadian girl. Letitia is growing up in a multilingual, multiliterate family of three children. She speaks Chao Chiu, her first language, and English at home, is learning Mandarin in kindergarten, and took Cantonese lessons when younger. Her parents, who immigrated to Canada from Vietnam, are literate in five languages, provide a rich home literacy learning environment, and have high expectations for their child's language and literacy learning in both the short and long term. Letitia, described as outgoing, articulate, ... and very interested in books and stories (p. 5), was just starting kindergarten when the study began. Thus, the author could observe her during her transition from home to school literacy, a critical research area given the widely recognized need for bridging the two literacy environments, particularly for multilingual children. The author visited Letitia in her home weekly for more than a year, playing the dual role of researcher and participant in the child's play and allowing her to direct and control the play to help overcome the obvious imbalance in power relations. Letitia welcomed the researcher's visits, and over time, the two developed a close and trusting relationship, placing the researcher in an especially favorable position for conducting her research and coming to understand how the child used play to express her understandings of self, literacy, and the world around her. The author draws on a variety of theoretical perspectives to frame the research, including emergent literacy and social constructivism and positioning theory on the situated and culturally specific nature of literacy learning and its embeddedness in power relations and identity construction. The author joins these perspectives with observations on the relations between play and literacy, which view play as an arena for identity construction and as a form of narrative or oral storytelling. Storytelling provides a particularly rich and unique analytical lens, allowing the author to examine the play episodes as literary and social texts and to explore play, literacy, and culture as an integrated whole rather than separately, as is commonly the case. Two introductory chapters (chapters 1 and 2) discuss the theoretical and methodological perspectives that frame the work and provide indepth information on Letitia's family and home context, gleaned from observations, conversations, and the close relationships established with family members. A selection of 10 of Letitia's play narratives, reflecting the two predominant play themes, home and school, are

The sweeping rise of new technologies has allowed for the normalization of digital tools and devices as powerful modes of communication and transmission of cultures, lifestyles, languages, texts, and power relations. Communication has definitely and irreversibly taken on a new turn/trajectory in cyberspace, where people have transferred their offline activities, experiences, interactions, and socialization. Cyberspace is a vast, open, and malleable space that gives momentum to human communication and velocity to the multi-layered process of transmission. Cyberspace, as an electronic and digital landscape, is widely used to create, share, and transmit information. It also contributes to storing information to enhance and extend human memory. The power dynamics of cyberspace manifest in its ability to extend human memory, empower communication, and globalize transmission. The fluid and constantly streaming aspect of cyberspace allows the free flow of ideas, texts, artefacts, knowledge, narratives, arts, cultural heritage, and identities, to cite but a few. By subsuming all these social, cultural, and epistemological actions, cyberspace has fostered a new culture, cyberculture. The French scholar Pierre Lévy defines cyberculture “as a set of material and intellectual techniques: practices, attitudes, modes of thinking and values that have developed alongside the growth of cyberspace. Understood as a synonym for ‘network,’ cyberculture offers a new medium of communication…” (Qtd. in Teixeira et al, 2017). Cyberspace provides multiple virtual platforms where various forms of culture are being stored and transmitted. Both cyberspace and cyberculture have become new digital paradigms that could be conceptualized as semiotic signifiers of the new society, hosting collective intelligence and providing electronic venues/spaces to empower/sustain local cultures and identities. The fact that cyberspace combines audio-visual, textual, and graphic materials can amply facilitate the transmission and the development of local and national cultures, oral or written. This paper is, then, a theoretical attempt at showcasing the potential of cyberspace and cyberculture to communicate, transmit, and empower local and national cultures and identities through the multiple platforms that digital technologies offer to the new society, which, at the same time, could reflect power relations.

This article contributes to the analysis, reflection, and propagation of the experiences of indigenous communities facing neoliberal states. It goes beyond theoretical perspectives, which are linked here to an empirical study based on the adoption and implementation of neoliberal policies by the Mexican state in a specific locality. This reading is based on the author's fieldwork, begun in July 2008, with the indigenous community of Mezcala, Jalisco, which employed participant observation, media collection and interviews. In order to highlight the contributions, challenges and shortcomings of this community, the article balances, on the one hand, the consequences of neoliberal policies and the power relations and institutions that maintain this community and support these policies; and, on the other hand, the conflicts that have truncated and permeated or prevented government plans, as well as the extent of community actions seeking to construct an autonomous project.

In order to minimise the impact on society in the case of severe disturbances affecting infrastructure systems, it is essential that these systems are resilient to failures, i.e. that they are able to continue operations or quickly recover a stable state after a major mishap. Numerous opportunities for taking measures to increase resilience of infrastructures exist already in the design phase of new elements in these systems. This paper therefore investigates to what extent resilience of the railway system is considered at the design stage of new railway tunnels in Sweden. The case study builds upon interviews with key stakeholders involved in the decision-making process regarding safety measures in six railway tunnel projects, comprising a total of 28 tunnels (representing the majority of contemporary railway tunnel projects in Sweden). The theoretical perspective is based upon insights from the fields of resilience engineering and risk governance. The results revealed that power relations between the different stakeholders largely influenced the decision-making process in the studied railway tunnel projects. Diverse roles and perspectives among these actors led to disagreements in the majority of the projects. As a result, both of the key stakeholders experienced that they were trapped in different kinds of double binds, i.e. situations requiring a choice between equally bad outcomes. These double binds, and the significant influence from local actors on decision-making, resulted in a restricted consideration of the system’s resilience on the regional and national levels. These findings underline the important relationship between decision-making at the local level in each railway tunnel project and the impact from these decisions on the system’s resilience at the global level. The paper therefore contributes to increased understanding of the way that micro-level decisions affect macro-level characteristics of complex socio-technical systems.

The key question this book addresses is: why do societies continue to exclude and marginalise disabled people? The answers provided by the contributors are based on range of studies providing careful analysis of everyday practices, power relations, ideas, and prejudices ‘at work’ to continue the exclusion of disabled people in everyday life. The book is a valuable contribution to gaining knowledge and understanding of the persistent, and often subtle, forces of exclusion in diverse areas and aspects of life. A major strength of the book is its multidisciplinary approach, the variety of disciplines and theoretical perspectives, and the diversity of methods in exploring various arenas of everyday life, all working in concert to create a multi-level and insightful analysis. The afterword places the contents of the book in an historical context of past ideologies and policies, and the future promise and policies based on a new disability human rights approach.

Sarah Orne Jewett is an American writer of the Nineteenth Century and is associated with American Realism. One of her most known works is the short story “A white heron”, published in 1886, which is about the relation of a girl and a hunter who are in search of a white heron. Given this context, I intend, in this essay, to analyze the literary narrative through the lens of ecofeminism. This theoretical perspective tries to interwoven the oppression of women, and other oppressed groups such as children, poor people, black people, and traditional people, and the exploitation of nature. To do so, this work undertakes an analytical path considering the resizing of the fictional figure towards its relation to nature represented in the diegesis. The theoretical framework is found, mainly, in Jytte Nhanege (2011), Chen Ling (2014), and Laila Fariha Zein and Adib Rifqi Setiawan (2017). Therefore, I realize that the relation erected between character and nature points out power relations and construction of hierarchies symbolizing oppression of women and destruction of nature by men.

To describe the application of critical ethnography to explain nurses' decisions to remain in or leave bedside nursing, and to describe researcher positioning and reflexivity. Enquiry into hospital nurses' decisions to remain in or leave bedside nursing positions has been conducted from a variety of theoretical perspectives by researchers adopting a range of methodological approaches. This research helps to explain how work environments can affect variables such as job satisfaction and turnover, but provides less insight into how personal and professional factors shape decisions to remain in or leave bedside nursing. A critical theoretical perspective was taken to examine the employment decisions made by nurses in a paediatric intensive care unit (PICU). Data was collected from nurses (n=31) through semi-structured interviews and unobtrusive observation. The authors describe critical ethnography as a powerful research framework for enquiry that allowed them to challenge assumptions about why nurses remain in or leave their jobs, and to explore how issues of fairness and equity contribute to these decisions. Critical ethnography offers a powerful methodology for investigations into complex interactions, such as those between nurses in a PICU. In adopting this methodology, researchers should be sensitised to manifestations of power, attend to their stance and location, and reflexion. The greatest challenges from this research included how to make sense of the insider position, how to acknowledge assumptions and allow these to be challenged, and how to ensure that power relationships in the environment and in the research were attended to.

The Review o f Higher Education Fall 1993, Volume 17, No. 1, pp. 21-41 Copyright © 1993 Association for the Study of Higher Education All Rights Reserved (ISSN 0162-5748) Feminist Scholarship in Core Higher Education Journals Barbara K. Townsend As a multidisciplinary field of study, higher education derives its con­ ceptual frameworks and methodologies from the social sciences and hu­ manities. Over the past two decades, contemporary feminism has sig­ nificantly influenced these disciplinary areas, stimulating a reexamination of their scholarship and curriculum from a feminist perspective as well as the development of new research paradigms (Calas and Smircich 1992; DuBois et al. 1985, Famham 1987, Langland and Gove 1981). Differentiating between biologically based sex and socially and cul­ turally constructed gender, feminists regard political, social, and eco­ nomic oppression based on gender as a reality that shapes women’s and men’s experiences (Epstein 1988). Feminist theory focuses on the power relationships between men and women, viewing past and existing rela­ tionships and arrangements as patriarchal or male-dominated. By focus­ ing on women’s experiences within this context and by researching ques­ tions whose answers might improve women’s conditions, feminist scholars aim to empower women and change the nature of relationships between women and men (Sprague and Zimmerman 1989). Those scholars who focus upon the experiences of women within the academy hope to gain Barbara K. Townsend is Professor and Chair of the Department of Leadership in the College of Education at Memphis State University. An earlier version of this paper was presented at the annual meeting of the Association for the Study of Higher Education in Boston, Massachusetts, in November 1991. Thanks are due to Estela Bensimon, Jack Newell, Susan Twombly, and anonymous reviewers for their com­ ments on this paper and to Cecelia Corey, who assisted me in finding articles dis­ cussed in this study. 22 The Review of Higher Education Fall 1993 and share insights that will ultimately lead to “making the academy a fruitful place for women to live and work” (Treichler 1985, 7). For ex­ ample, Mary Belenky et al. (1986) studied female college students’ “ways of knowing” and indicated how the teaching-learning process needs to change to accommodate these ways; Estela Bensimon (1991) analyzed gender differences in administrative leadership styles of college presi­ dents and demonstrated how current leadership theories fail to do justice to women’s leadership styles; and Nadya Aisenberg and Mona Harring­ ton (1988) examined factors limiting women faculty and recommended ways for individual faculty and institutions to change this situation. By putting women’s experiences at the center of its study of the acad­ emy, by pointing out institutional activities that perpetuate discrimina­ tion by gender, and by developing theories and models reflective of both genders’ experiences, feminist scholarship has the potential to generate a transformation of the academy. However, if such scholarship is to in­ fluence the operation of the academy, it needs to be disseminated to college and university faculty and administrators, including those who study higher education. These individuals may be faculty who teach about higher education and conduct research on it, or they may be practition­ ers who, while holding faculty or administrative positions in colleges and universities or education-related agencies, wish to understand higher ed­ ucation from a theoretical perspective. Since “perhaps journals both cre­ ate and mirror their fields” (Silverman 1987), inclusion of feminist schol­ arship in higher education’s core journals would seem to be both a necessary condition and an indication of feminist scholarship’s ability to influence the study and the operation of higher education institutions. In short, feminist theory has an explicit political agenda with implica­ tions for the daily functioning of the academy. For this perspective to influence the perspective of those who administer the academy, it needs to become known to them. Publication in higher education’s core jour­ nals helps ensure this awareness and knowledge. The extent to which feminist scholarship has transformed various disciplines has been well documented (e.g., DuBois et al. 1985; Kelly and Korsmeyer 1991; Langland and Gove 1991), but the extent to which feminist scholarship has been published in core higher education jour­ nals has rarely...

Who is sensitising whom? A participatory interview guide development as an awareness tool within a health care research project

Purpose of the Study: This study emphasizes the contribution of fiction in highlighting the American exercise of power around the world predominantly Pakistan and Afghanistan. It investigates how America has become a dictating body deciding the life and death of human beings mainly in South Asian developing countries.&#x0D; Methodology: Being Qualitative, this study uses Eaglestone’s (2000) close reading technique to analyze words and structure of the texts of Khalid Hosseini's The Kite Runner and Nadeem Aslam Khan’s The Blind Man’s Garden. It develops a descriptive thesis leading to construct arguments by drawing a theoretical framework from Mbembe’s necropolitics (2003). Mbembe took his inspiration from Foucault’s idea of bio-power. Modern narrative discourse on sovereignty and its relation to war is taken as the main subject of necropolitics. Mbembe’s idea of sovereignty as an exercise to get control of the mortality of the enemy helps to interpret the texts via the close reading method.&#x0D; Main Findings: This study evaluated two novels to assert that necropolitics by taking its four basic concepts, power, war, politics, and death was the actual controlling power of a country. It analyzed fictional characters to argue how individuals endured hardships because of the necropolitical exercise of America and Russia in Afghanistan. Mbembe’s conception of necropolitics helps in understanding fiction.&#x0D; Applications of this study: The present study has significant implications from both theoretical and interpretative perspectives. Necropolitics, originally a political notion is reworked in fiction, which asserts that using this concept, power relations, their roots, and exercise around the world can be explored in various fields. This study contributes to dismantling the latent necropolitics in the society represented in fiction. It elevates the social and political consciousness of the general public of South Asia, particularly Pakistan and Afghanistan. This study can be helpful in the field of psychology to popularize the notion of necropolitics in contemporary society.&#x0D; Novelty/Originality of this study: Comparatively a new field, Necropolitics has been discussed in the fields of medical sciences and education. This study significantly highlights its existence in the field of literary studies. Fiction as a direct reflection of society helps in deconstructing the prevailing exercise of necropolitics in South Asian society. It is also helpful in raising the social and political consciousness of South Asian people.