4,791 research outputs found

    Control Flow Analysis for SF Combinator Calculus

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    Programs that transform other programs often require access to the internal structure of the program to be transformed. This is at odds with the usual extensional view of functional programming, as embodied by the lambda calculus and SK combinator calculus. The recently-developed SF combinator calculus offers an alternative, intensional model of computation that may serve as a foundation for developing principled languages in which to express intensional computation, including program transformation. Until now there have been no static analyses for reasoning about or verifying programs written in SF-calculus. We take the first step towards remedying this by developing a formulation of the popular control flow analysis 0CFA for SK-calculus and extending it to support SF-calculus. We prove its correctness and demonstrate that the analysis is invariant under the usual translation from SK-calculus into SF-calculus.Comment: In Proceedings VPT 2015, arXiv:1512.0221

    A method of producing cardiac arrest in the dog.

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    Thesis (M.A.)--Boston Universit

    The Surgical Management of Hirschsprung\u27s Disease

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    The operative technique which we have employed for 17 children with Hirschsprung\u27s disease is presented. The procedure offers certain advantages over the original Duhamel operation and over the classic Swenson operation. It can be recommended as a safe operation for Hirschsprung\u27s disease, and, in our experience, has given satisfactory results

    Defective spermatogenesis: Martin et al. respond

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    This is an Open Access article - Copyright @ National Institute of Environmental Health Science.BACKGROUND: Male reproductive tract abnormalities such as hypospadias and cryptorchidism, and testicular cancer have been proposed to comprise a common syndrome together with impaired spermatogenesis with a common etiology resulting from the disruption of gonadal development during fetal life, the testicular dysgenesis syndrome (TDS). The hypothesis that in utero exposure to estrogenic agents could induce these disorders was first proposed in 1993. The only quantitative summary estimate of the association between prenatal exposure to estrogenic agents and testicular cancer was published over 10 years ago, and other systematic reviews of the association between estrogenic compounds, other than the potent pharmaceutical estrogen diethylstilbestrol (DES), and TDS end points have remained inconclusive. OBJECTIVES: We conducted a quantitative meta-analysis of the association between the end points related to TDS and prenatal exposure to estrogenic agents. Inclusion in this analysis was based on mechanistic criteria, and the plausibility of an estrogen receptor (ER)-α–mediated mode of action was specifically explored. RESULTS: We included in this meta-analysis eight studies investigating the etiology of hypospadias and/or cryptorchidism that had not been identified in previous systematic reviews. Four additional studies of pharmaceutical estrogens yielded a statistically significant updated summary estimate for testicular cancer. CONCLUSIONS: The doubling of the risk ratios for all three end points investigated after DES exposure is consistent with a shared etiology and the TDS hypothesis but does not constitute evidence of an estrogenic mode of action. Results of the subset analyses point to the existence of unidentified sources of heterogeneity between studies or within the study population

    Happiness Drives Performance

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    The article of record as published may be found at https://markets.businessinsider.com/news/stocks/happiness-drives-performance-103120049

    Program transformations enable verification tools to solve interactive fiction games

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    We present a work-in-progress case study on using program verification tools, specifically model-checkers for C programs, to solve simple interactive fiction games from the early 1980s. Off-the-shelf model-checking tools are unable to handle the games in their original form. In order to work around this, we apply a series of program transformations that do not change the behaviour of the program. An interesting aspect of these games is that they use a simple, interpreted language to script in-game events. This turns out to be the most difficult part of the program for verification tools to handle. Our case study thus provides some insights that may be applicable more generally to verification and analysis of programs that interpret scripting languages

    Analysis of MiniJava programs via translation to ML

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    MiniJava is a subset of the object-oriented programming language Java. Standard ML is the canonical representative of the ML family of functional programming languages, which includes F# and OCaml. Different program analysis and verification tools and techniques have been developed for both Java-like and ML-like languages. Naturally, the tools developed for a particular language emphasise accurate treatment of language features commonly used in that language. In Java, this means objects with mutable properties and dynamic method dispatch. In ML, this means higher order functions and algebraic datatypes with pattern matching. We propose to translate programs from one language into the other and use the target language's tools for analysis and verification. By doing so, we hope to identify areas for improvement in the target language's tools and suggest techniques, perhaps as used in the source language's tools, that may guide their improvement. More generally, we hope to develop tools for reasoning about programs that are more resilient to changes in the style of code and representation of data. We begin our programme by outlining a translation from MiniJava to ML that uses only the core features of ML; in particular, it avoids the use of ML's mutable references. MiniJava is a subset of the object-oriented programming language Java. Standard ML is the canonical representative of the ML family of functional programming languages, which includes F# and OCaml. Different program analysis and verification tools and techniques have been developed for both Java-like and ML-like languages. Naturally, the tools developed for a particular language emphasise accurate treatment of language features commonly used in that language. In Java, this means objects with mutable properties and dynamic method dispatch. In ML, this means higher order functions and algebraic datatypes with pattern matching. We propose to translate programs from one language into the other and use the target language's tools for analysis and verification. By doing so, we hope to identify areas for improvement in the target language's tools and suggest techniques, perhaps as used in the source language's tools, that may guide their improvement. More generally, we hope to develop tools for reasoning about programs that are more resilient to changes in the style of code and representation of data. We begin our programme by outlining a translation from MiniJava to ML that uses only the core features of ML; in particular, it avoids the use of ML's mutable references
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