43742881
Erratum ("The small model property: how small can it be?" Volume 178, Number 1 [2002], pages 279-293)
209098159
The Code Validation Tool CVT: Automatic Verification of a Compilation Process.
14822655
Translation Validation
15658777
Translation Validation: From SIGNAL to C
Translation validation is an alternative to the verification of translators (compilers, code generators). Rather than proving in advance that the compiler always produces a target code which correctly implements the source code (compiler verification), each individual translation (i.e. a run of the compiler) is followed by a validation phase which verifies that the target code produced on this run correctly implements the submitted source program. In order to be a practical alternative to compiler verification, a key feature of this validation is its full automation. 
 
Since the validation process attempts to "unravel" the transformation effected by the translators, its task becomes increasingly more difficult (and necessary) with the increase of sophistication and variety of the optimizations methods employed by the translator. In this paper we address the practicability of translation validation for highly optimizing, industrial code generators from Signal, a widely used synchronous language, to C. We introduce new abstraction techniques as part of the automation of our approach.
7986917
Translation Validation: From DC+ to C*
Translation validation is an alternative to the verification of translators (compilers, code generators). Rather than proving in advance that the compiler always produces a target code which correctly implements the source code (compiler verification), each individual translation (i.e. a run of the compiler) is followed by a validation phase which verifies that the target code produced on this run correctly implements the submitted source program. In order to be a practical alternative to compiler verification, a key feature of this validation is its full automation. 
 
In this paper we demonstrate the feasibility of translation validation for industrial code generators from DC+ -a widely used intermediate format for synchronous languages- to C. We explain the compilation pattern from DC+ to C and advocate new abstraction techniques for a fragment of first order logic as part of the automation of our approach.
15882359
Deciding Equality Formulas by Small Domains Instantiations
We introduce an efficient decision procedure for the theory of equality based on finite instantiations. When using the finite instantiations method, it is a common practice to take a range of [1..n] (where n is the number of input non-Boolean variables) as the range for all non-Boolean variables, resulting in a state-space of nn. Although various attempts to minimize this range were made, typically they either required various restrictions on the investigated formulas or were not very effective. In many cases, the nn state-space cannot be handled by BDD-based tools within a reasonable amount of time. In this paper we show that significantly smaller domains can be algorithmically found, by analyzing the structure of the formula. We also show an upper bound for the state-space based on this analysis. This method enabled us to verify formulas containing hundreds of integer and floating point variables.
33236770
Formal Verification of Stabilizing Systems
This paper links too formerly rather disjoint areas: formal verification and stabilization. Stabilization is a vitally emerging paradigm in fault tolerant distributed computing; formal verification investigates mathematically rigorous techniques to reason about systems.
1155385
Implementing statecharts in PROMELA/SPIN
We translate statecharts into PROMELA, the input language of the SPIN verification system, using extended hierarchical automata as an intermediate format. We discuss two possible frameworks for this translation, leading to either sequential or parallel code. We show that in this context the sequential code can be verified more efficiently than the parallel code. We conclude with a discussion of an application of the resulting translator to a well-known case study, which demonstrates the feasibility of linear temporal logic model checking of statecharts.
62729675
The Composite Information System Laboratory (CISL) Project at MIT
The Composite Information Systems Laboratory (CISL) at MIT is involved in research on the strategic, organizational and technical aspects of the integration of multiple heterogeneous database systems. In this paper we examine the scope of the work being done at CISL. Certain research efforts in the technical areas of system integration are emphasized; in particular semantic aspects of the integration process and methods for tracking data sources in composite information systems.
1004881
Correctness conditions for highly available replicated databases
Abstract : Correctness conditions are given which describe some of the properties exhibited by highly available distributed database systems such as the SHARD (System for Highly Available Replicated Data) system currently being developed at Computer Corporation of America. This system allows a database application to continue operation in the face of communication failures, including network partitions. A penalty is paid for this extra availability: the usual correctness conditions, serializability of transactions and preservation of integrity constraints, are not guaranteed. However, it is still possible to make interesting claims about the behavior of the system. The kinds of claims which can be proved include bounds on the costs of violation of integrity constraints, and fairness guarantees. In contrast to serializability's all-or-nothing character, this work has a continuous flavor: small changes in available information lead to small perturbations in correctness conditions. This work is novel, because there has been very little previous success in stating interesting properties which are guaranteed by nonserializable systems. (Author)
1603358
A Procedure for Mediation of Queries to Sources in Disparate Contexts
This paper discusses the algorithm we are using for the mediation of queries to disparate information sources in a Context Interchange system, where information sources may have di erent interpretations arising from their respective context. Queries are assumed to be formulated without regard for semantic heterogeneity, and are rewritten to corresponding mediated queries by taking into account the semantics of data codi ed in axioms associated with sources and receivers (the corresponding context theories). Our approach draws upon recent advances in abductive logic programming and presents an integration of techniques for query rewriting and semantic query optimization. We also demonstrate how this can be e ciently implemented using the constraint logic programming system ECLiPSe.