177 research outputs found

    Cooperation Among Theorem Provers

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    In many years of research, a number of powerful theorem-proving systems have arisen with differing capabilities and strengths. Resolution theorem provers (such as Kestrel's KITP or SRI's SNARK) deal with first-order logic with equality but not the principle of mathematical induction. The Boyer-Moore theorem prover excels at proof by induction but cannot deal with full first-order logic. Both are highly automated but cannot accept user guidance easily. The purpose of this project, and the companion project at Kestrel, has been to use the category-theoretic notion of logic morphism to combine systems with different logics and languages

    Deductive Biocomputing

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    BACKGROUND: As biologists increasingly rely upon computational tools, it is imperative that they be able to appropriately apply these tools and clearly understand the methods the tools employ. Such tools must have access to all the relevant data and knowledge and, in some sense, “understand” biology so that they can serve biologists' goals appropriately and “explain” in biological terms how results are computed. METHODOLOGY/PRINCIPAL FINDINGS: We describe a deduction-based approach to biocomputation that semiautomatically combines knowledge, software, and data to satisfy goals expressed in a high-level biological language. The approach is implemented in an open source web-based biocomputing platform called BioDeducta, which combines SRI's SNARK theorem prover with the BioBike interactive integrated knowledge base. The biologist/user expresses a high-level conjecture, representing a biocomputational goal query, without indicating how this goal is to be achieved. A subject domain theory, represented in SNARK's logical language, transforms the terms in the conjecture into capabilities of the available resources and the background knowledge necessary to link them together. If the subject domain theory enables SNARK to prove the conjecture—that is, to find paths between the goal and BioBike resources—then the resulting proofs represent solutions to the conjecture/query. Such proofs provide provenance for each result, indicating in detail how they were computed. We demonstrate BioDeducta by showing how it can approximately replicate a previously published analysis of genes involved in the adaptation of cyanobacteria to different light niches. CONCLUSIONS/SIGNIFICANCE: Through the use of automated deduction guided by a biological subject domain theory, this work is a step towards enabling biologists to conveniently and efficiently marshal integrated knowledge, data, and computational tools toward resolving complex biological queries

    Open architectures for formal reasoning and deductive technologies for software development

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    The objective of this project is to develop an open architecture for formal reasoning systems. One goal is to provide a framework with a clear semantic basis for specification and instantiation of generic components; construction of complex systems by interconnecting components; and for making incremental improvements and tailoring to specific applications. Another goal is to develop methods for specifying component interfaces and interactions to facilitate use of existing and newly built systems as 'off the shelf' components, thus helping bridge the gap between producers and consumers of reasoning systems. In this report we summarize results in several areas: our data base of reasoning systems; a theory of binding structures; a theory of components of open systems; a framework for specifying components of open reasoning system; and an analysis of the integration of rewriting and linear arithmetic modules in Boyer-Moore using the above framework

    AMPHION: Specification-based programming for scientific subroutine libraries

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    AMPHION is a knowledge-based software engineering (KBSE) system that guides a user in developing a diagram representing a formal problem specification. It then automatically implements a solution to this specification as a program consisting of calls to subroutines from a library. The diagram provides an intuitive domain oriented notation for creating a specification that also facilitates reuse and modification. AMPHION'S architecture is domain independent. AMPHION is specialized to an application domain by developing a declarative domain theory. Creating a domain theory is an iterative process that currently requires the joint expertise of domain experts and experts in automated formal methods for software development

    Men's Appraisals of Their Military Experiences in World War II: A 40-Year Perspective

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    Using data on veterans from the longitudinal Harvard Study of Adult Development (N=241), we focused on subjective aspects of military service. We examined how veterans of World War II appraised specific dimensions of military service directly after the war and over 40 years later, as well as the role of military service in their life course. In addition to examining change in appraisals, we examined how postwar appraisals of service mediated the effects of objective aspects of service, and how postwar psychological adjustment and health mediated the effects of postwar appraisals, on later-life appraisals. Men’s appraisals at both time points were generally, but not highly, positive, and revealed remarkable consistency over four decades. Postwar appraisals strongly predicted later-life appraisals and mediated the effects of objective service variables. The effects of postwar appraisals were not carried forward through psychological adjustment or midlife health. Better adjustment, however, was negatively related to later-life appraisals. Results reinforce the idea that how men perceive their military experiences may be more important in predicting outcomes than the experiences themselves. Results are discussed in light of the sample characteristics, the historical context of World War II, and the complexities of appraisal and retrospection

    Modes of incorporation: a conceptual and empirical critique

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    Entering the debate over segmented assimilation, this paper seeks to refocus discussion on a core, but neglected claim: that inter-group disparities among immigrant offspring derive from differences in a contextual feature shared by immigrant and immigrant descendants: a nationality’s mode of incorporation.  The paper engages in both theoretical and empirical assessment.  We critically examine the concept of mode of incorporation, demonstrating that its operational implications have not been correctly understood; consequently, the core hypothesis has never been appropriately tested.  The second part of the paper implements those tests, making use of the Children of Immigrants Longitudinal Survey.  We do so by using nationality as a proxy for mode of incorporation, systematically contrasting more advantaged against less advantaged nationalities.    We show: (a) that tests systematically varying modes classified as more or less advantageous yield inconsistent outcomes; (b) that positive or negative modes of incorporation are associated with few long-lasting effects; (c) that differences in governmental reception are particularly unlikely to be associated with interethnic disparities; and (d) that compared to theoretically relevant nationalities, neither Mexicans, a nationality assigned to a negative mode of incorporation, nor pre-Mariel Cubans, a nationality assigned to positive mode of incorporation, prove distinctive

    A theorem proving framework for the formal verification of Web Services Composition

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    We present a rigorous framework for the composition of Web Services within a higher order logic theorem prover. Our approach is based on the proofs-as-processes paradigm that enables inference rules of Classical Linear Logic (CLL) to be translated into pi-calculus processes. In this setting, composition is achieved by representing available web services as CLL sentences, proving the requested composite service as a conjecture, and then extracting the constructed pi-calculus term from the proof. Our framework, implemented in HOL Light, not only uses an expressive logic that allows us to incorporate multiple Web Services properties in the composition process, but also provides guarantees of soundness and correctness for the composition.Comment: In Proceedings WWV 2011, arXiv:1108.208

    The embedding of transnational entrepreneurs in diaspora networks:Leveraging the assets of foreignness

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    In this paper we examine how foreign actors capitalize on their ethnic identity to gain skills and capabilities that enable them to operate in a new and strange environment. We explore the mechanisms by which Bulgarian entrepreneurs in London use their ethnic identity to develop competitive advantage and business contacts. We find that the entrepreneurs studied gain access to a diaspora network, which enables them to develop essential business capabilities and integrate knowledge from both home and host country environments. The diaspora community possesses a collective asset (transactive memory) that allows its members to remove competition from the interfirm level to the network level (i.e., diaspora networks vs. networks of native businesspeople). Additionally, the cultural identity and networks to which community members have access provide bridging capabilities that allow diaspora businesspeople to make links to host country business partners and thus embed themselves in the host country environment. Thus, this paper adds to the growing body of work showing how foreignness can serve as an asset in addition to its better-known role as a liability

    Urbanization, migration, and development

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