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Although building systems from components has attractions, this approach also has problems. Can we be sure that a certain configuration of components is correct? Can it perform as well as a monolithic system? Our paper answers these questions for the Ensemble communication architecture by showing how, with help of the Nuprl formal system, configurations may(More)
Ensemble is a widely used group communication system that supports distributed programming by providing precise guarantees for synchronization, message ordering, and message delivery. Ensemble eases the task of distributed-application programming, but as a result, ensuring the correctness of Ensemble itself is a diicult problem. In this paper we use I/O(More)
MetaPRL is the latest system to come out of over twenty five years of research by the Cornell PRL group. While initially created at Cornell, MetaPRL is currently a collaborative project involving several universities in several countries. The MetaPRL system combines the properties of an interactive LCF-style tactic-based proof assistant, a logical(More)
Theorem proving techniques are particularly well suited for reasoning about arithmetic above the bit level and for relating diierent levels of abstraction. In this paper we show h o w a non-restoring integer square root algorithm can be transformed to a very eecient hardware implementation. The top level is a Standard ML function that operates on unbounded(More)
We present a foundation for a computational meta-theory of languages with bindings implemented in a computer-aided formal reasoning environment. Our theory provides the ability to reason abstractly about operators, languages, open-ended languages, classes of languages, <i>etc.</i> The theory is based on the ideas of higher-order abstract syntax, with an(More)
Higher-order logics are expressive tools for tasks ranging from formalizing the foundations of mathematics to large-scale software veriication and synthesis. Because of their complexity, proofs in higher-order logics often use a combination of interactive proving together with computationally-intensive tactic applications that perform proof automation. As(More)
We present a theorem proving environment for the development of reliable and efficient group communication systems. Our approach makes methods of automated deduction applicable to the implementation of real-world systems by linking the Ensemble group communication toolkit to the NuPRL proof development system. We present tools for importing Ensemble's code(More)
Theorem provers for higher-order logics often use tactics to code automated proof search. Tactics use a procedural metalanguage to perform both algorithmic and heuristic proof search, as well as compu-tationally intensive domain-speciic proof procedures. The generality of tactic provers has a performance penalty; the speed of proof search lags far behind(More)