Lesson plan

FDR (software)

FDR (Failures-Divergences Refinement) and subsequently FDR2, FDR3 and FDR4 are refinement checking software tools, designed to check formal models expressed in communicating sequential processes (CSP). The tools were originally developed by Formal Systems (Europe) Ltd. Bill Roscoe of the Department of Computer Science, University of Oxford devised many of the algorithms used by the tool and Michael Goldsmith was instrumental in the implementation. FDR2 was developed by Department of Computer Science, University of Oxford from where it was freely available for academic and other non-commercial use. FDR is often described as a model checker, but is technically a refinement checker, in that it converts two CSP process expressions into Labelled Transition Systems (LTSs), and then determines whether one of the processes is a refinement of the other within some specified semantic model (traces, failures, failures/divergence and some other alternatives). FDR2 applies various state-space compression algorithms to the process LTSs in order to reduce the size of the state-space that must be explored during a refinement check. FDR2 has gone through many releases, having replaced the earlier tool now referred to as FDR1 in 1995. It has been succeeded by FDR3, a completely re-written version incorporating amongst other things parallel execution and an integrated type checker.…

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Article summary

FDR (Failures-Divergences Refinement) and subsequently FDR2, FDR3 and FDR4 are refinement checking software tools, designed to check formal models expressed in communicating sequential processes (CSP). The tools were originally developed by Formal Systems (Europe) Ltd. Bill Roscoe of the Department of Computer Science, University of Oxford devised many of the algorithms used by the tool and Michael Goldsmith was instrumental in the implementation. FDR2 was developed by Department of Computer Science, University of Oxford from where it was freely available for academic and other non-commercial use. FDR is often described as a model checker, but is technically a refinement checker, in that it converts two CSP process expressions into Labelled Transition Systems (LTSs), and then determines whether one of the processes is a refinement of the other within some specified semantic model (traces, failures, failures/divergence and some other alternatives). FDR2 applies various state-space compression algorithms to the process LTSs in order to reduce the size of the state-space that must be explored during a refinement check. FDR2 has gone through many releases, having replaced the earlier tool now referred to as FDR1 in 1995. It has been succeeded by FDR3, a completely re-written version incorporating amongst other things parallel execution and an integrated type checker.…

Key claims

  1. release date: 2008 — source: Wikipedia · confidence 0.95

Discussion questions

  1. Summarise the article in your own words. Which single claim would you verify first, and why?
  2. The record states that the release date is "2008". What evidence would count against this claim?
  3. Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
  4. If two sources disagreed about one of these facts, what would you need in order to trust one over the other?

Bibliography

  1. Wikipedia https://en.wikipedia.org/w/index.php?oldid=1258471775

Key claims and bibliography are generated from the same tracked claims and sources as the article page.