The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform

Steve Counsell - One of the best experts on this subject based on the ideXlab platform.

  • SEFM - Non-local Choice and Implied Scenarios
    2010 8th IEEE International Conference on Software Engineering and Formal Methods, 2010
    Co-Authors: Robert M. Hierons, Steve Counsell
    Abstract:

    A number of issues, such as non-local choice and implied scenarios, that arise in Message Sequence Charts (MSCs) have been investigated in the past. However, existing research on these two issues show disagreements regarding how they are related. In this paper, we analyse the relations among existing conditions for non-local choice free and Closure Conditions (CCs) for implied scenarios. On the basis of this, we propose a new definition for non-local choice and a non-local choice free condition derived from CCs of implied scenarios. Compared to existing conditions, we argue that the new condition covers more non-local choices that satisfy the Informal Idea of non-local choice. We formally show that the existence of non-local choices in an MSC specification results in implied scenarios and the appearance of implied scenarios according to corresponding CCs means there are non-local choices in the specification.

  • Non-local Choice and Implied Scenarios
    2010 8th IEEE International Conference on Software Engineering and Formal Methods, 2010
    Co-Authors: Robert M. Hierons, Steve Counsell
    Abstract:

    A number of issues, such as non-local choice and implied scenarios, that arise in Message Sequence Charts (MSCs) have been investigated in the past. However, existing research on these two issues show disagreements regarding how they are related. In this paper, we analyse the relations among existing conditions for non-local choice free and Closure Conditions (CCs) for implied scenarios. On the basis of this, we propose a new definition for non-local choice and a non-local choice free condition derived from CCs of implied scenarios. Compared to existing conditions, we argue that the new condition covers more non-local choices that satisfy the Informal Idea of non-local choice. We formally show that the existence of non-local choices in an MSC specification results in implied scenarios and the appearance of implied scenarios according to corresponding CCs means there are non-local choices in the specification.

Robert M. Hierons - One of the best experts on this subject based on the ideXlab platform.

  • SEFM - Non-local Choice and Implied Scenarios
    2010 8th IEEE International Conference on Software Engineering and Formal Methods, 2010
    Co-Authors: Robert M. Hierons, Steve Counsell
    Abstract:

    A number of issues, such as non-local choice and implied scenarios, that arise in Message Sequence Charts (MSCs) have been investigated in the past. However, existing research on these two issues show disagreements regarding how they are related. In this paper, we analyse the relations among existing conditions for non-local choice free and Closure Conditions (CCs) for implied scenarios. On the basis of this, we propose a new definition for non-local choice and a non-local choice free condition derived from CCs of implied scenarios. Compared to existing conditions, we argue that the new condition covers more non-local choices that satisfy the Informal Idea of non-local choice. We formally show that the existence of non-local choices in an MSC specification results in implied scenarios and the appearance of implied scenarios according to corresponding CCs means there are non-local choices in the specification.

  • Non-local Choice and Implied Scenarios
    2010 8th IEEE International Conference on Software Engineering and Formal Methods, 2010
    Co-Authors: Robert M. Hierons, Steve Counsell
    Abstract:

    A number of issues, such as non-local choice and implied scenarios, that arise in Message Sequence Charts (MSCs) have been investigated in the past. However, existing research on these two issues show disagreements regarding how they are related. In this paper, we analyse the relations among existing conditions for non-local choice free and Closure Conditions (CCs) for implied scenarios. On the basis of this, we propose a new definition for non-local choice and a non-local choice free condition derived from CCs of implied scenarios. Compared to existing conditions, we argue that the new condition covers more non-local choices that satisfy the Informal Idea of non-local choice. We formally show that the existence of non-local choices in an MSC specification results in implied scenarios and the appearance of implied scenarios according to corresponding CCs means there are non-local choices in the specification.

Giovanni Birolo - One of the best experts on this subject based on the ideXlab platform.

  • A Witness Extraction Technique by Proof Normalization Based on Interactive Realizability
    arXiv: Logic, 2013
    Co-Authors: Giovanni Birolo
    Abstract:

    We present a new set of reductions for derivations in natural deduction that can extract witnesses from closed derivations of simply existential formulas in Heyting Arithmetic (HA) plus the Excluded Middle Law restricted to simply existential formulas (EM1), a system motivated by its interest in proof mining. The reduction we have for classical logic are quite different from all existing ones. They are inspired by the Informal Idea of learning by making falsifiable hypothesis and checking them, and by the interactive realizability interpretation. We extract the witnesses directly from derivations in HA+EM1 by reduction, without encoding derivations by a realizability interpretation.

  • Interactive Realizability, Monads and Witness Extraction
    arXiv: Logic in Computer Science, 2013
    Co-Authors: Giovanni Birolo
    Abstract:

    In this dissertation we collect some results about "interactive realizability", a realizability semantics that extends the Brouwer-Heyting-Kolmogorov interpretation to (sub-)classical logic, more precisely to first-order intuitionistic arithmetic (Heyting Arithmetic, HA) extended by the law of the excluded middle restricted to simply existential formulas formulas (EM1), a system motivated by its interest in proof mining. We describe the interactive interpretation of a classical proof involving real numbers. The statement we prove is a simple but non-trivial fact about points in the real plane. The proof employs EM1 to deduce properties of the ordering on the real numbers, which is undecidable and thus problematic from a constructive point of view. We present a new set of reductions for derivations in natural deduction that can extract witnesses from closed derivations of simply existential formulas in HA + EM1. The reduction we present are inspired by the Informal Idea of learning by making falsifiable hypothesis and checking them, and by the interactive realizability interpretation. We extract the witnesses directly from derivations in HA + EM1 by reduction, without encoding derivations by a realizability interpretation. We give a new presentation of interactive realizability with a more explicit syntax. We express interactive realizers by means of an abstract framework that applies the monadic approach used in functional programming to modified realizability, in order to obtain less strict notions of realizability that are suitable to classical logic. In particular we use a combination of the state and exception monads in order to capture the learning-from-mistakes nature of interactive realizers.

R.k. Shyamasundar - One of the best experts on this subject based on the ideXlab platform.

  • Compositional interaction specifications for SystemC
    Fourth ACM and IEEE International Conference on Formal Methods and Models for Co-Design 2006. MEMOCODE '06. Proceedings., 2006
    Co-Authors: F. Doucet, I.h. Krueger, R. Gupta, R.k. Shyamasundar
    Abstract:

    SystemC is being widely used for system-level modeling of system-on-chip. When designing this class of system, one of the main challenges is to guarantee the correctness of the implementation. This can be especially difficult for designs that are composed of concurrent components with lot of interactions. Most designers use a component-based design approach, where one has an Informal Idea of how the design should behave, define component specifications, implement and assemble the components into a program, and then check for correctness by simulating the design with a number of testbenches. With this methodology, bugs often go undetected because when using simulation, it is very difficult to test for all possible interactions. To overcome this limitation, our goal is to establish a specification and verification methodology for SystemC. To address the scalability issue, which is a serious limiting factor in state-based verification approaches, we use the concepts of behavioral types; allowing us to effectively infer system properties from properties of its components. In this paper, we answer the following questions: (1) what is a behavioral type? (2) how are behavioral type defined? and (3) how to use the behavioral types in a compositional verification methodology

  • MEMOCODE - Compositional interaction specifications for SystemC
    Fourth ACM and IEEE International Conference on Formal Methods and Models for Co-Design 2006. MEMOCODE '06. Proceedings., 2006
    Co-Authors: F. Doucet, I.h. Krueger, R. Gupta, R.k. Shyamasundar
    Abstract:

    SystemC is being widely used for system-level modeling of system-on-chip. When designing this class of system, one of the main challenges is to guarantee the correctness of the implementation. This can be especially difficult for designs that are composed of concurrent components with lot of interactions. Most designers use a component-based design approach, where one has an Informal Idea of how the design should behave, define component specifications, implement and assemble the components into a program, and then check for correctness by simulating the design with a number of testbenches. With this methodology, bugs often go undetected because when using simulation, it is very difficult to test for all possible interactions. To overcome this limitation, our goal is to establish a specification and verification methodology for SystemC. To address the scalability issue, which is a serious limiting factor in state-based verification approaches, we use the concepts of behavioral types; allowing us to effectively infer system properties from properties of its components. In this paper, we answer the following questions: (1) what is a behavioral type? (2) how are behavioral type defined? and (3) how to use the behavioral types in a compositional verification methodology.

Nikolai K. Vereshchagin - One of the best experts on this subject based on the ideXlab platform.

  • CSL - Variants of Realizability for Propositional Formulas and the Logic of the Weak Law of Excluded Middle
    Computer Science Logic, 2002
    Co-Authors: Alexey Chernov, Dmitriy P. Skvortsov, Elena Z. Skvortsova, Nikolai K. Vereshchagin
    Abstract:

    It is unknown, whether the logic of propositional formulas that are realizable in the sense of Kleene has a finite or recursive axiomatization. In this paper another approach to realizability of propositional formulas is studied. This approach is based on the following Informal Idea: a formula is realizable if it has a "simple" realization for each substitution. More precisely, logical connectives are interpreted as operations on sets of natural numbers and a formula is interpreted as a combined operation; if some sets are substituted for variables, then elements of the result are called realizations. A realization (a natural number) is simple if it has low Kolmogorov complexity, and a formula is called realizable if it has at least one simple realization whatever sets are substituted. Similar definitions may be formulated in arithmetical terms. A few "realizabilities" of this kind are considered and it is proved that all of them give the same finitely axiomatizable logic, namely, the logic of the weak law of excluded middle.