6,187 research outputs found

    Classical logic, continuation semantics and abstract machines

    Get PDF
    One of the goals of this paper is to demonstrate that denotational semantics is useful for operational issues like implementation of functional languages by abstract machines. This is exemplified in a tutorial way by studying the case of extensional untyped call-by-name λ-calculus with Felleisen's control operator 𝒞. We derive the transition rules for an abstract machine from a continuation semantics which appears as a generalization of the ÂŹÂŹ-translation known from logic. The resulting abstract machine appears as an extension of Krivine's machine implementing head reduction. Though the result, namely Krivine's machine, is well known our method of deriving it from continuation semantics is new and applicable to other languages (as e.g. call-by-value variants). Further new results are that Scott's D∞-models are all instances of continuation models. Moreover, we extend our continuation semantics to Parigot's λΌ-calculus from which we derive an extension of Krivine's machine for λΌ-calculus. The relation between continuation semantics and the abstract machines is made precise by proving computational adequacy results employing an elegant method introduced by Pitts

    Symbolic execution proofs for higher order store programs

    Get PDF
    Higher order store programs are programs which store, manipulate and invoke code at runtime. Important examples of higher order store programs include operating system kernels which dynamically load and unload kernel modules. Yet conventional Hoare logics, which provide no means of representing changes to code at runtime, are not applicable to such programs. Recently, however, new logics using nested Hoare triples have addressed this shortcoming. In this paper we describe, from top to bottom, a sound semi-automated verification system for higher order store programs. We give a programming language with higher order store features, define an assertion language with nested triples for specifying such programs, and provide reasoning rules for proving programs correct. We then present in full our algorithms for automatically constructing correctness proofs. In contrast to earlier work, the language also includes ordinary (fixed) procedures and mutable local variables, making it easy to model programs which perform dynamic loading and other higher order store operations. We give an operational semantics for programs and a step-indexed interpretation of assertions, and use these to show soundness of our reasoning rules, which include a deep frame rule which allows more modular proofs. Our automated reasoning algorithms include a scheme for separation logic based symbolic execution of programs, and automated provers for solving various kinds of entailment problems. The latter are presented in the form of sets of derived proof rules which are constrained enough to be read as a proof search algorithm

    The cooperative endorsement of a strategic game

    Get PDF
    This note provides a way to translate a strategic game to a characteristic cooperative game assuming that the set of players of the cooperative game is the set of pure actions of the strategic game. Coalitions generated with only one action for each player and the total coalition characterize the Core. We calculate the worth of the total coalition to guarantee the non-emptyness condition. In particular, for a two-player game, this value is equal to the maximal sum of the diagonals.Cooperative games, core

    Methodological Approach for the Development of a Simplified Residential Building Energy Estimation in Temperate Climate

    Get PDF
    Energy ratings and minimum requirements for thermal envelopes and heating and air conditioning systems emerged as tools to minimize energy consumption and greenhouse gas emissions, improve energy e ciency and promote greater transparency with regard to energy use in buildings. In Latin America, not all countries have building energy e ciency regulations, many of them are voluntary and more than 80% of the existing initiatives are simplified methods and are centered in energy demand analysis and the compliance of admissible values for di erent indicators. However, the application of these tools, even when simplified, is reduced. The main objective is the development of a simplified calculation method for the estimation of the energy consumption of multifamily housing buildings. To do this, an energy model was created based on the real use and occupation of a reference building, its thermal envelope and its thermal system’s performance. This model was simulated for 42 locations, characterized by their climatic conditions, whilst also considering the thermal transmittance fulfilment. The correlation between energy consumption and the climatic conditions is the base of the proposed method. The input data are seven climatic characteristics. Due to the sociocultural context of Latin America, the proposed method is estimated to have more possible acceptance and applications than other more complex methods, increasing the rate of buildings with an energy assessment. The results have demonstrated a high reliability in the prediction of the statistical models created, as the determination coe cient (R2) is nearly 1 for cooling and heating consumption

    A semantic foundation for hidden state

    Get PDF
    We present the first complete soundness proof of the antiframe rule, a recently proposed proof rule for capturing information hiding in the presence of higher-order store. Our proof involves solving a non-trivial recursive domain equation, and it helps identify some of the key ingredients for soundness

    Assessing Structure and Function in Glaucoma

    Get PDF
    Glaucoma is a heterogeneous group of optic nerve diseases sharing an accelerated degeneration of retinal ganglion cells (RGCs) that, if untreated, leads to progressive and irreversible loss of visual function. Worldwide, glaucoma is the second leading cause of blindness. Of the many types of glaucoma, primary open-angle glaucoma (POAG) is probably the most common one in Western countries. Probably less than half of all people who have the disease are aware of it

    Cap a un inventari dels sainets valencians

    Get PDF

    La filosofia del dolor

    Get PDF
    • 

    corecore