Cooperation Among Theorem Provers

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

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

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

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

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

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

A 'snip' in time: what is the best age to circumcise?

<p>Abstract</p> <p>Background</p> <p>Circumcision is a common procedure, but regional and societal attitudes differ on whether there is a need for a male to be circumcised and, if so, at what age. This is an important issue for many parents, but also pediatricians, other doctors, policy makers, public health authorities, medical bodies, and males themselves.</p> <p>Discussion</p> <p>We show here that infancy is an optimal time for clinical circumcision because an infant's low mobility facilitates the use of local anesthesia, sutures are not required, healing is quick, cosmetic outcome is usually excellent, costs are minimal, and complications are uncommon. The benefits of infant circumcision include prevention of urinary tract infections (a cause of renal scarring), reduction in risk of inflammatory foreskin conditions such as balanoposthitis, foreskin injuries, phimosis and paraphimosis. When the boy later becomes sexually active he has substantial protection against risk of HIV and other viral sexually transmitted infections such as genital herpes and oncogenic human papillomavirus, as well as penile cancer. The risk of cervical cancer in his female partner(s) is also reduced. Circumcision in adolescence or adulthood may evoke a fear of pain, penile damage or reduced sexual pleasure, even though unfounded. Time off work or school will be needed, cost is much greater, as are risks of complications, healing is slower, and stitches or tissue glue must be used.</p> <p>Summary</p> <p>Infant circumcision is safe, simple, convenient and cost-effective. The available evidence strongly supports infancy as the optimal time for circumcision.</p

Using Prior Knowledge: Problems and Solutions

Encoding knowledge is time consuming and expensive. A possible solution to reduce the cost of developing a new knowledge base (KB) is to reuse existing knowledge. Previous work addressing this problem has focused on standards for representing, exchanging, and accessing knowledge (Genesereth and Fikes 1992), (Chaudhri et al. 1998), and on creating large repositories of knowledge (Lenat and Guha 1990). Results on the level of reuse achievable have been reported (Cohen et al. 1999). In this paper, we focus on the process of reuse and report a case study on constructing a KB by reusing existing knowledge. The reuse process involved the following steps: translation, comprehension, slicing, reformulation, and merging. We discuss technical problems encountered at each of these steps and explain how we solved them