The Use of Proof Planning for Cooperative Theorem Proving

AbstractWe describebarnacle: a co-operative interface to theclaminductive theorem proving system. For the foreseeable future, there will be theorems which cannot be proved completely automatically, so the ability to allow human intervention is desirable; for this intervention to be productive the problem of orienting the user in the proof attempt must be overcome. There are many semi-automatic theorem provers: we call our style of theorem provingco-operative, in that the skills of both human and automaton are used each to their best advantage, and used together may find a proof where other methods fail. The co-operative nature of thebarnacleinterface is made possible by the proof planning technique underpinningclam. Our claim is that proof planning makes new kinds of user interaction possible.Proof planning is a technique for guiding the search for a proof in automatic theorem proving. Common patterns of reasoning in proofs are identified and represented computationally as proof plans, which can then be used to guide the search for proofs of new conjectures. We have harnessed the explanatory power of proof planning to enable the user to understand where the automatic prover got to and why it is stuck. A user can analyse the failed proof in terms ofclam's specification language, and hence override the prover to force or prevent the application of a tactic, or discover a proof patch. This patch might be to apply further rules or tactics to bridge the gap between the effects of previous tactics and the preconditions needed by a currently inapplicable tactic

Compromised user credentials detection using temporal features: A prudent based approach

© 2017 ACM. This study exposes a serious and rapidly growing cyber threat of compromised legitimate user credentials which is very effective for cyber-criminals to gain trusted relationships with the account owners. Such a compromised user\u27s credentials ultimately result in damage incurred by the attacker at large-scale. Moreover, the detection of compromised legitimate user activities is crucial in competitive and sensitive organizations because wrong data is more difficult to clean from the database. The proposed study presents a novel approach to detect compromised users\u27 activity in a live database. Our approach uses a composition of prudence analysis, ripple down rules (RDR) and simulated experts (SE) to detect and identify accounts that experience a sudden change in behavior. We collected data from a sensitive running database for a period of Six months and evaluate the proposed technique. The results show that this combined model can fully detect outlier user\u27s activity and can provide useful information for the concerned decision maker

Recess Rules: Why the Undervalued Playtime May Be America's Best Investment for Healthy Kids and Healthy Schools

Identifies opportunities for increasing children's physical activity. Focuses on the Sports4Kids model of addressing children's health through play and explores possible funding disparities in the field of physical activity

The Lia Fund: An Adventure in Philanthropy

Randy Lia Weil made two highly unusual decisions about the $5 million she left to be donated after her death. The first was that she appointed 14 people she knew and trusted to select the organizations and individuals who would receive funding. Most of them were lifelong activists with decades of passionate dedication to environmental, cultural and social justice issues. The second unusual thing was that she left no instructions for how or to whom they should give her bequest. She trusted them to decide.This would prove to be an adventure and a discovery, and not without its challenges for the participants. Everyone sincerely wanted to be a responsible grantmaker and do what Randy would have wanted. But it was a complex journey to turn a group of passionate individuals into a group of effective funders. Before they could make any grants, they had to agree on their mission, vision, and values. They also had to decide how they would operate and make decisions in a way that honored Randy and the values that led her to choose them. It was a tall order.After spending a year planning to establish the Foundation, The Lia Fund awarded grants to 107 organizations from 2007 to 2013. Most of the grants ranged from$5,000 to $25,000. In total the Foundation gave away$5 million. This is the story of what The Lia Fund did, how they did it, and what they learned. It describes the impact of this type of grantmaking on some of the most important issues of our time. It also looks at what foundations and individual donors might learn from this adventure in philanthropy

$=€=Bitcoin?

Bitcoin (and other virtual currencies) have the potential to revolutionize the way that payments are processed, but only if they become ubiquitous. This Article argues that if virtual currencies are used at that scale, it would pose threats to the stability of the financial system—threats that have been largely unexplored to date. Such threats will arise because the ability of a virtual currency to function as money is very fragile—Bitcoin can remain money only for so long as people have confidence that bitcoins will be readily accepted by others as a means of payment. Unlike the U.S. dollar, which is backed by both a national government and a central bank, and the euro, which is at least backed by a central bank, there is no institution that can shore up confidence in Bitcoin (or any other virtual currency) in the event of a panic. This Article explores some regulatory measures that could help address the systemic risks posed by virtual currencies, but argues that the best way to contain those risks is for regulated institutions to out-compete virtual currencies by offering better payment services, thus consigning virtual currencies to a niche role in the economy. This Article therefore concludes by exploring how the distributed ledger technology pioneered by Bitcoin could be adapted to allow regulated entities to provide vastly more efficient payment services for sovereign currency-denominated transactions, while at the same time seeking to avoid concentrating the provision of those payment services within “too big to fail” banks