State-based Programs Research Articles

A Case Study in Automated Verification Based on Trace Abstractions

In [14], we proposed a framework for the automatic verification of reactive<br />systems. Our main tool is a decision procedure, Mona, for Monadic<br />Second-order Logic (M2L) on finite strings. Mona translates a formula in<br />M2L into a finite-state automaton. We show in [14] how traces, i.e. finite<br />executions, and their abstractions can be described behaviorally. These<br />state-less descriptions can be formulated in terms of customized temporal<br />logic operators or idioms.<br />In the present paper, we give a self-contained, introductory account of<br />our method applied to the RPC-memory specification problem of the 1994<br />Dagstuhl Seminar on Specification and Refinement of Reactive Systems.<br />The purely behavioral descriptions that we formulate from the informal<br />specifications are formulas that may span 10 pages or more.<br />Such descriptions are a couple of magnitudes larger than usual temporal<br />logic formulas found in the literature on verification. To securely<br />write these formulas, we introduce Fido [16] as a reactive system description<br />language. Fido is designed as a high-level symbolic language for<br />expressing regular properties about recursive data structures.<br />All of our descriptions have been verified automatically by Mona from<br />M2L formulas generated by Fido.<br />Our work shows that complex behaviors of reactive systems can be<br />formulated and reasoned about without explicit state-based programming.<br />With Fido, we can state temporal properties succinctly while enjoying<br />automated analysis and verification.

Prevalence of Mobility and Self-care Disability— United States, 1990

An estimated 43 million persons in the United States have a disability; the estimated annual economic impact of disabilities--representing loss of wages, medical-care expenditures, and additional household expenditures--is approximately $176.7 billion. The Institute of Medicine recently recommended surveillance and systematic collection of information at the national and state levels to assist in program planning and evaluation for state-based programs for the prevention of disabilities and secondary conditions (i.e., health conditions resulting from a disability). To characterize state-specific disability patterns and better plan for funding of disability services, the National Institute of Disability and Rehabilitation Research (NIDRR) and CDC assessed data from the 1990 census on two forms of disability: difficulty with mobility and self-care activities. This report summarizes the results of the assessment for persons aged > or = 16 years.

Combining static concurrency analysis with symbolic execution

Static concurrency analysis detects anomalous synchronization patterns in concurrent programs, but may also report spurious errors involving infeasible execution paths. Integrated application of static concurrency analysis and symbolic execution sharpens the results of the former without incurring the full costs of the latter when applied in isolation. Concurrency analysis acts as a path selection mechanism for symbolic execution, while symbolic execution acts as a pruning mechanism for concurrency analysis. Methods of combining the techniques follow naturally from explicit characterization and comparison of the state spaces explored by each, suggesting a general approach for integrating state-based program analysis techniques in a software development environment.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Taking History to the Public: The Kansas Historian-in-Residence Program

IN 1979 the Kansas Committee for the Humanities (KCH), a state-based program of the National Endowment for the Humanities, and Fort Hays State University in Hays, Kansas sponsored a historian-in-residence program. Funded by a joint one-year matching grant, the project was designed to bring humanities programs to the citizens of northwest Kansas. The region is essentially rural, its population dependent primarily upon agriculture and ranching. Its towns, which are often separated by twentyfive to thirty miles of farmland, range in size from 63 inhabitants to almost 17,000, although most of the communities hold fewer than 3,000 residents.'