Proceedings Twelfth International Workshop on the ACL2 Theorem Prover and its Applications (Vienna, Austria, July 12-13, 2014)

This volume contains the proceedings of the Twelfth International Workshop on the ACL2 Theorem Prover and Its Applications, ACL2'14, a two-day workshop held in Vienna, Austria, on July 12-13, 2014. ACL2 workshops occur at approximately 18-month intervals and provide a major technical forum for researchers to present and discuss improvements and extensions to the theorem prover, comparisons of ACL2 with other systems, and applications of ACL2 in formal verification. ACL2 2014 is organized in cooperation with ACM SIGPLAN. ACL2 is a state-of-the-art automated reasoning system that has been successfully applied in academia, government, and industry for specification and verification of computing systems and in teaching computer science courses. In 2005, Boyer, Kaufmann, and Moore were awarded the 2005 ACM Software System Award for their work in ACL2 and the other theorem provers in the Boyer-Moore family. The proceedings of ACL2 2014 include 13 peer reviewed technical papers. Each submission was reviewed by at least three Program Committee members. Some papers received four and sometimes even five reviews. In addition to the technical papers, the workshop includes two invited talks, one by Mike Gordon, titled Linking ACL2 and HOL: past achievements and future prospects and one by Magnus Myreen, titled Machine-code verification: experience of tackling medium-sized case studies using 'decompilation into logic. The workshop also includes several Rump sessions discussing ongoing research and a panel discussion about low level code verification. We thank the members of the Program Committee and their sub-reviewers for providing careful and detailed reviews of all the papers. We thank the members of the Steering Committee for their help and guidance. We thank EasyChair for the use of its excellent conference management system. We thank EPTCS and the arXiv for publishing the workshop proceedings in an open-access format. We thank the FLoC organizing committee for their support. May 2014, Freek Verbeek and Julien Schmalt

A formally verified deadlock-free routing function in a fault-tolerant NoC architecture

A novel fault-tolerant adaptive wormhole routing function for Networks-on-Chips (NoCs) is presented. The routing function guarantees absence of deadlocks and livelocks up to two faulty channels. The routing logic does not require reconfiguration when a fault occurs. The routes themselves are dynamic. Based on the faults in the network, alternative routes are used to reroute packets. Routing decisions are based only on local knowledge, which allows for fast switching. Our approach does not use any costly virtual channels. As we do not prohibit cyclic dependencies, the routing function provides minimal routing from source to destination even in the presence of faults. We have implemented the architecture design using synthesizable HDL. To ensure deadlock freedom, we have extended a formally verified deadlock detection algorithm to deal with fault tolerant designs. For a 20×20 mesh, we have formally proven deadlock freedom of our design in all of the 2,878,800 configurations in which two channels are faulty. We supply experimental results showing the performance of our architecture

Zebrafish development and regeneration: new tools for biomedical research

Basic research in pattern formation is concerned with the generation of phenotypes and tissues. It can therefore lead to new tools for medical research. These include phenotypic screening assays, applications in tissue engineering, as well as general advances in biomedical knowledge. Our aim here is to discuss this emerging field with special reference to tools based on zebrafish developmental biology. We describe phenotypic screening assays being developed in our own and other labs. Our assays involve: (i) systemic or local administration of a test compound or drug to zebrafish in vivo, (ii) the subsequent detection or "readout" of a defined phenotypic change. A positive readout may result from binding of the test compound to a molecular target involved in a developmental pathway. We present preliminary data on assays for compounds that modulate skeletal patterning, bone turnover, immune responses, inflammation and early-life stress. The assays use live zebrafish embryos and larvae as well as adult fish undergoing caudal fin regeneration. We describe proof-of-concept studies on the localised targeting of compounds into regeneration blastemas using microcarriers. Zebrafish are cheaper to maintain than rodents, produce large numbers of transparent eggs, and some zebrafish assays could be scaled-up into medium and high throughput screens. However, advances in automation and imaging are required. Zebrafish cannot replace mammalian models in the drug development pipeline. Nevertheless, they can provide a cost-effective bridge between cell-based assays and mammalian whole-organism model