In classic program synthesis algorithms, such as counterexample-guided inductive synthesis (CEGIS), the algorithms alternate between a synthesis phase and an oracle (verification) phase. Many synthesis algorithms use ...
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This paper presents a computational framework to approach the resilience properties of the systems in many different domains. The proposal models elementary behaviors of the systems by means of a set of recursive func...
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We present the Leon verification system for a subset of the Scala programming language. Along with several functional features of Scala, Leon supports imperative constructs such as mutations and loops, using a transla...
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ISBN:
(纸本)9781450320641
We present the Leon verification system for a subset of the Scala programming language. Along with several functional features of Scala, Leon supports imperative constructs such as mutations and loops, using a translation into recursive functional form. Both properties and programs in Leon are expressed in terms of user-defined functions. We discuss several techniques that led to an eficient semi-decision procedure for first-order constraints with recursive functions, which is the core solving engine of Leon. We describe a generational unrolling strategy for recursive templates that yields smaller satisfiable formulas and ensures completeness for counterexamples. We illustrate the current capabilities of Leon on a set of examples, such as data structure implementations;we show that Leon successfully finds bugs or proves completeness of pattern matching as well as validity of function postconditions. Copyright 2013 ACM.
Enhancing human-machine interaction is critical to aerospace applications. An essential requirement in safety critical systems is the clear need to guarantee trustworthiness of a system as well as V&V (Verificatio...
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ISBN:
(纸本)9781728156668
Enhancing human-machine interaction is critical to aerospace applications. An essential requirement in safety critical systems is the clear need to guarantee trustworthiness of a system as well as V&V (Verification and Validation). However, the current state of the art concerning decision support systems lacks effective tools in this area. The Coherence Function Package, introduced in this research, is a tool towards providing assurance that the action needed has the approval of both the human and the machine in terms of SAFETY. These algorithms shed light on the future of an Explainable Artificial Intelligence (XAI, [1]), that fosters a synergy between these two factors. This vital requirement that has been further underscored after the tragic events of the Boeing 737 Max 8 crashes [2]. Preliminary results show that the proposed approach is not only able to detect any errors in the system, it also assists in circumventing conflicts leading to incoherence and suggests a preferred solution in real-time.
It cannot be decided whether a pushdown automaton accepts using constant pushdown height, with respect to the input length, or not. Furthermore, in the case of acceptance in constant height, the height cannot be bound...
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ISBN:
(纸本)9783030232474;9783030232467
It cannot be decided whether a pushdown automaton accepts using constant pushdown height, with respect to the input length, or not. Furthermore, in the case of acceptance in constant height, the height cannot be bounded by any recursive function in the size of the description of the machine. In contrast, in the restricted case of pushdown automata over a one-letter input alphabet, i.e., unary pushdown automata, the above property becomes decidable. Moreover, if the height is bounded by a constant in the input length, then it is at most exponential with respect to the size of the description of the pushdown automaton. This bound cannot be reduced. Finally, if a unary pushdown automaton uses nonconstant height to accept, then the height should grow at least as the logarithm of the input length. This bound is optimal.
We briefly summarize some of the findings on non-recursive trade-offs, which were first observed by Meyer and Fischer in their seminal paper on "Economy of Description by Automata, Grammars, and Formal Systems&qu...
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ISBN:
(数字)9783030229962
ISBN:
(纸本)9783030229962;9783030229955
We briefly summarize some of the findings on non-recursive trade-offs, which were first observed by Meyer and Fischer in their seminal paper on "Economy of Description by Automata, Grammars, and Formal Systems" in 1971. This general phenomenon is about conversion problems between different (computational) description models that cannot be solved efficiently. Indeed, they evade solvability a forteriori because the change in description size caused by such a conversion cannot be bounded above by any recursive function. Hence, a result on non-recursive trade-offs can alternatively be interpreted as a compression of the description model with arbitrary space gains. Since 1971 there has been a steadily growing list of results where this phenomenon has been observed, and it appears that non-recursive trade-offs are "almost everywhere."
Lambda calculi are often used as intermediate representations for compilers. However, they require extensions to handle higher-level features of programming languages. In this paper we show how to construct an IR base...
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ISBN:
(数字)9783030336363
ISBN:
(纸本)9783030336363;9783030336356
Lambda calculi are often used as intermediate representations for compilers. However, they require extensions to handle higher-level features of programming languages. In this paper we show how to construct an IR based on System F-omega(mu). which supports recursive functions and datatypes, and describe how to compile it to System F-omega(mu). Our IR was developed for commercial use at the IOHK company, where it is used as part of a compilation pipeline for smart contracts running on a blockchain.
We determine the critical exponent and the recurrence function of complementary symmetric Rote sequences. The formulae are expressed in terms of the continued fraction expansions associated with the S-adic representat...
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The first seeds of mathematical intuitionism germinated in Europe over a century ago in the constructive tendencies of Borel, Baire, Lebesgue, Poincaré, Kronecker and others. The flowering was the work of one man...
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