994 research outputs found
Strategic term rewriting and its application to a VDM-SL to SQL conversion
We constructed a tool, called VooDooM, which converts datatypes in Vdm-sl into Sql relational data models. The conversion involves transformation of algebraic types to maps and products, and pointer introduction. The conversion is specified as a theory of refinement by calculation. The implementation technology is strategic term rewriting in Haskell, as supported by the Strafunski bundle. Due to these choices of theory and technology, the road from theory to practise is straightforward.Fundação para a Ciência e a Tecnologia (FCT) - POSI/ICHS/44304/2002Agência de Inovação (ADI) - ∑!223
Formal Verification of Hand-Coded Software Some Industrial Experiments and Lessons Learnt
International audienceThis paper gives an account of an ongoing attempt to prove the safety properties, of a hand-coded safety critical embedded software of industrial size. The method used is based on annotating the C source files with assertions that encode the safety-related functional properties to be satisfied by the software, and then generating proof obligations to be discharged by some theorem provers. We discuss what has been achieved and what difficulties were encountered, from which we derive requirements regarding the evolution of the verification tools involved in that experiment
A theorem prover-based analysis tool for object-oriented databases
We present a theorem-prover based analysis tool for object-oriented database systems with integrity constraints. Object-oriented database specifications are mapped to higher-order logic (HOL). This allows us to reason about the semantics of database operations using a mechanical theorem prover such as Isabelle or PVS. The tool can be used to verify various semantics requirements of the schema (such as transaction safety, compensation, and commutativity) to support the advanced transaction models used in workflow and cooperative work. We give an example of method safety analysis for the generic structure editing operations of a cooperative authoring system
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Automated verification of refinement laws
Demonic refinement algebras are variants of Kleene algebras. Introduced by von Wright as a light-weight variant of the refinement calculus, their intended semantics are positively disjunctive predicate transformers, and their calculus is entirely within first-order equational logic. So, for the first time, off-the-shelf automated theorem proving (ATP) becomes available for refinement proofs. We used ATP to verify a toolkit of basic refinement laws. Based on this toolkit, we then verified two classical complex refinement laws for action systems by ATP: a data refinement law and Back's atomicity refinement law. We also present a refinement law for infinite loops that has been discovered through automated analysis. Our proof experiments not only demonstrate that refinement can effectively be automated, they also compare eleven different ATP systems and suggest that program verification with variants of Kleene algebras yields interesting theorem proving benchmarks. Finally, we apply hypothesis learning techniques that seem indispensable for automating more complex proofs
Meta-F*: Proof Automation with SMT, Tactics, and Metaprograms
We introduce Meta-F*, a tactics and metaprogramming framework for the F*
program verifier. The main novelty of Meta-F* is allowing the use of tactics
and metaprogramming to discharge assertions not solvable by SMT, or to just
simplify them into well-behaved SMT fragments. Plus, Meta-F* can be used to
generate verified code automatically.
Meta-F* is implemented as an F* effect, which, given the powerful effect
system of F*, heavily increases code reuse and even enables the lightweight
verification of metaprograms. Metaprograms can be either interpreted, or
compiled to efficient native code that can be dynamically loaded into the F*
type-checker and can interoperate with interpreted code. Evaluation on
realistic case studies shows that Meta-F* provides substantial gains in proof
development, efficiency, and robustness.Comment: Full version of ESOP'19 pape
The use of proof plans in tactic synthesis
We undertake a programme of tactic synthesis. We first formalize the notion of
a tactic as a rewrite rule, then give a correctness criterion for this by means of a
reflection mechanism in the constructive type theory OYSTER. We further formalize
the notion of a tactic specification, given as a synthesis goal and a decidability
goal. We use a proof planner. CIAM. to guide the search for inductive proofs
of these, and are able to successfully synthesize several tactics in this fashion.
This involves two extensions to existing methods: context-sensitive rewriting and
higher-order wave rules. Further, we show that from a proof of the decidability
goal one may compile to a Prolog program a pseudo- tactic which may be run to
efficiently simulate the input/output behaviour of the synthetic tacti
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