Results 1 - 10
of
20
Safe Reasoning with Logic LTS
, 2008
"... Previous work has introduced the setting of Logic LTS, together with a variant of ready simulation as fully-abstract refinement preorder, which allows one to compose operational specifications using a CSP-style parallel operator as well as the propositional connectives conjunction and disjunction. I ..."
Abstract
-
Cited by 7 (1 self)
- Add to MetaCart
Previous work has introduced the setting of Logic LTS, together with a variant of ready simulation as fully-abstract refinement preorder, which allows one to compose operational specifications using a CSP-style parallel operator as well as the propositional connectives conjunction and disjunction. In this paper, we show how a temporal logic for specifying safety properties may be embedded into Logic LTS so that (a) the temporal operators are compositional for ready simulation and (b) ready simulation, when restricted to pairs of processes and formulas, coincides with the logic’s satisfaction relation. The utility of this setting as a semantic foundation for mixed operational and temporal-logic specification languages is demonstrated via a simple example.
Modal Interface Automata
- Logical Methods in Computer Science 9(3:4
, 2013
"... cent combination IOMTS of IA and Larsen’s Modal Transition Systems (MTS) are es-tablished frameworks for specifying interfaces of system components. However, neither IA nor IOMTS consider conjunction that is needed in practice when a component shall satisfy multiple interfaces, while Larsen’s MTS-co ..."
Abstract
-
Cited by 6 (3 self)
- Add to MetaCart
(Show Context)
cent combination IOMTS of IA and Larsen’s Modal Transition Systems (MTS) are es-tablished frameworks for specifying interfaces of system components. However, neither IA nor IOMTS consider conjunction that is needed in practice when a component shall satisfy multiple interfaces, while Larsen’s MTS-conjunction is not closed and Benes ̌ et al.’s conjunction on disjunctive MTS does not treat internal transitions. In addition, IOMTS-parallel composition exhibits a compositionality defect. This article defines conjunction (and also disjunction) on IA and disjunctive MTS and proves the operators to be ‘correct’, i.e., the greatest lower bounds (least upper bounds) wrt. IA- and resp. MTS-refinement. As its main contribution, a novel interface theory called Modal Interface Automata (MIA) is introduced: MIA is a rich subset of IOMTS featuring explicit output-must-transitions while input-transitions are always allowed im-plicitly, is equipped with compositional parallel, conjunction and disjunction operators, and allows a simpler embedding of IA than Nyman’s. Thus, it fixes the shortcomings of related work, without restricting designers to deterministic interfaces as Raclet et al.’s modal interface theory does. 1.
Assume-Guarantee Reasoning for Safe Component Behaviours
"... Abstract. We formulate a sound and complete assume-guarantee framework for reasoning compositionally about safety properties of component behaviours. The specification of a component, which constrains the temporal ordering of input and output interactions with the environment, is expressed in terms ..."
Abstract
-
Cited by 3 (1 self)
- Add to MetaCart
(Show Context)
Abstract. We formulate a sound and complete assume-guarantee framework for reasoning compositionally about safety properties of component behaviours. The specification of a component, which constrains the temporal ordering of input and output interactions with the environment, is expressed in terms of two prefix-closed sets of traces: an assumption and guarantee. The framework supports dynamic reasoning about components and specifications, and includes rules for parallel composition, logical conjunction corresponding to independent development, and quotient for incremental synthesis. Practical applicability of the framework is demonstrated by considering a simple printing example.
An Algebraic Theory of Interface Automata
"... We formulate a compositional specification theory for interface automata, where a component model specifies the allowed sequences of input and out-put interactions with the environment. A trace-based linear-time refinement is provided, which is the weakest preorder preserving substitutivity of com-p ..."
Abstract
-
Cited by 3 (0 self)
- Add to MetaCart
We formulate a compositional specification theory for interface automata, where a component model specifies the allowed sequences of input and out-put interactions with the environment. A trace-based linear-time refinement is provided, which is the weakest preorder preserving substitutivity of com-ponents, and is weaker than the classical alternating simulation defined on interface automata. Since our refinement allows a component to be refined by refusing to produce any output, we also define a refinement relation that guarantees safety and progress. The theory includes the operations of paral-lel composition to support the structural composition of components, logical conjunction and disjunction for independent development, hiding to support abstraction of interfaces, and quotient for incremental synthesis of compo-nents. Our component formulation highlights the algebraic properties of the specification theory for both refinement preorders, and is shown to be fully abstract with respect to observation of communication mismatches. Exam-ples of independent and incremental component development are provided.
Ensuring Reachability by Design
, 2012
"... Modular design aims at decomposing systems as a set of distinct components that can be independently developed and then assembled all together. Interfaces are then attached to components; they abstract implementation details while exposing to the environment relevant information about cross-compone ..."
Abstract
-
Cited by 2 (0 self)
- Add to MetaCart
(Show Context)
Modular design aims at decomposing systems as a set of distinct components that can be independently developed and then assembled all together. Interfaces are then attached to components; they abstract implementation details while exposing to the environment relevant information about cross-component interactions. Whereas state-of-the-art on interfaces essentially consider independent implementability of safety properties, we consider in this paper reachability properties, which are in general not compositional. The approach we advocate consists in controlling the design flow of components, that is, the evolution of their interfaces through combinations and refinements, in order to ensure a reachability property by construction. Modal specifications are widely acknowledged as a suitable specification formalism for interface-based design. In order to obtain the required expressivity, we extend them with marked states to model states to be reached. We then develop an algebra with both logical and structural composition operators ensuring reachability properties by design.
METROII: A Design Environment for Cyber-Physical Systems ABHIJIT DAVARE, Intel Labs
"... Cyber-Physical Systems are integrations of computation and physical processes and as such, will be in-creasingly relevant to industry and people. The complexity of designing CPS resides in their heterogeneity. Heterogeneity manifest itself in modeling their functionality as well as in the implementa ..."
Abstract
-
Cited by 2 (1 self)
- Add to MetaCart
Cyber-Physical Systems are integrations of computation and physical processes and as such, will be in-creasingly relevant to industry and people. The complexity of designing CPS resides in their heterogeneity. Heterogeneity manifest itself in modeling their functionality as well as in the implementation platforms that include a multiplicity of components such as microprocessors, signal processors, peripherals, memories, sensors and actuators often integrated on a single chip or on a small package such as a multi-chip module. We need a methodology, tools and environments where heterogeneity can be dealt with at all levels of abstraction and where different tools can be integrated. We present here Platform-Based Design as the CPS methodology of choice and METROII, a design environment that supports it. We present the metamodeling approach fol-lowed in METROII, how to couple the functionality and implementation platforms of CPS, and the simulation technology that supports the analysis of CPS and of their implementation. We also present examples of use and the integration of METROII with another popular design environment developed at Verimag, BIP.
Nondeterministic Modal Interfaces
"... Interface theories are employed in the component-based design of concurrent systems. They often emerge as combinations of Interface Automata (IA) and Modal Transition Systems (MTS), e.g., Nyman et al.’s IOMTS, Bauer et al.’s MIO, Raclet et al.’s MI or our MIA. In this paper, we generalise MI to no ..."
Abstract
-
Cited by 1 (1 self)
- Add to MetaCart
(Show Context)
Interface theories are employed in the component-based design of concurrent systems. They often emerge as combinations of Interface Automata (IA) and Modal Transition Systems (MTS), e.g., Nyman et al.’s IOMTS, Bauer et al.’s MIO, Raclet et al.’s MI or our MIA. In this paper, we generalise MI to non-deterministic interfaces, for which we resolve the longstanding conflict between unspecified inputs being allowed in IA but forbidden in MTS. With this solu-tion we achieve, in contrast to related work, an associative parallel composition, a compositional preorder, a conjunction on interfaces with dissimilar alphabets supporting perspective-based specifications, and a quotienting operator for decomposing nondeterministic specifications in a single theory.
Application of Interface Theories to the Separate Compilation of Synchronous Programs
"... Abstract—We study the problem of separate compilation, i.e., the generation of modular code, for the discrete time part of block-diagrams formalisms such as Simulink, Modelica, or Scade. Code is modular in that it is generated for a given composite block independently from context (i.e., without kno ..."
Abstract
-
Cited by 1 (0 self)
- Add to MetaCart
(Show Context)
Abstract—We study the problem of separate compilation, i.e., the generation of modular code, for the discrete time part of block-diagrams formalisms such as Simulink, Modelica, or Scade. Code is modular in that it is generated for a given composite block independently from context (i.e., without knowing in which diagrams the block is to be used) and using minimal information about the internals of the block. Just using off-the-shelf C code generation (e.g., as available in Simulink) does not provide modular code. Separate compilation was solved by Lublinerman et al. for the special case of single-clocked diagrams, in which all signals are updated at a same unique clock. For the same case, Pouzet and Raymond proposed algorithms that scale-up properly to real-size applications. The technique of Lublinerman et al. was extended to some classes of multi-clocked and timed diagrams. We study this problem in its full generality and we show that it can be cast to a special class of controller synthesis problems by relying on recently proposed modal interface theories.
Richer Interface Automata with Optimistic and Pessimistic Compatibility
, 2013
"... Modal transition systems are a popular semantic underpinning of interface theories, such as Nyman et al.’s IOMTS and Bauer et al.’s MIO, which facilitate component-based reasoning of concurrent systems. Our interface theory MIA repaired a compositional flaw of IOMTS-refinement and introduced a conju ..."
Abstract
- Add to MetaCart
Modal transition systems are a popular semantic underpinning of interface theories, such as Nyman et al.’s IOMTS and Bauer et al.’s MIO, which facilitate component-based reasoning of concurrent systems. Our interface theory MIA repaired a compositional flaw of IOMTS-refinement and introduced a conjunction operator. In this paper, we first modify MIA to properly deal with internal computations including internal must-transitions, which were largely ignored already in IOMTS. We then study a MIA variant that adopts MIO’s pessimistic – rather than IOMTS’ optimistic – view on component compatibility and define, for the first-time in a pessimistic, non-deterministic setting, conjunction and disjunction on interfaces. For the pessimistic MIA variant we also provide a mechanism for extending alphabets when refining interfaces, which is a desired feature in practice. We illustrate our advancements via a small example.
On Refinements of Boolean and Parametric Modal Transition Systems
, 2013
"... We consider the extensions of modal transition systems (MTS), namely Boolean MTS and parametric MTS and we investigate the refinement problems over both classes. Firstly, we reduce the problem of modal refinement over both classes to a problem solvable by a QBF solver and provide experimental resul ..."
Abstract
- Add to MetaCart
We consider the extensions of modal transition systems (MTS), namely Boolean MTS and parametric MTS and we investigate the refinement problems over both classes. Firstly, we reduce the problem of modal refinement over both classes to a problem solvable by a QBF solver and provide experimental results showing our technique scales well. Secondly, we extend the algorithm for thorough refinement of MTS providing better complexity then via reductions to previously studied problems. Finally, we investigate the relationship between modal and thorough refinement on the two classes and show how the thorough refinement can be approximated by the modal refinement.
