Proving Non-Termination via Loop Acceleration

We present the first approach to prove non-termination of integer programs that is based on loop acceleration. If our technique cannot show non-termination of a loop, it tries to accelerate it instead in order to find paths to other non-terminating loops automatically. The prerequisites for our novel loop acceleration technique generalize a simple yet effective non-termination criterion. Thus, we can use the same program transformations to facilitate both non-termination proving and loop acceleration. In particular, we present a novel invariant inference technique that is tailored to our approach. An extensive evaluation of our fully automated tool LoAT shows that it is competitive with the state of the art

Mystic Microsoft : a journey of transformation in the halls of high technology

258 p. ; 23 cm.Libro ElectrónicoWhere do you go if you want to grow spiritually? A church? A monastery? India? Tibet? What about the heart of high-tech corporate multinationalism? If you’ve ever thought that God only works through formal religious or spiritual channels, think again! Mystic Microsoft demonstrates that when there’s sincerity of heart and a willingness to offer oneself into whatever Life brings, God can (and will) find a way to guide one’s inner growth in any setting. In this fascinating story, one of Microsoft’s most visible technology experts during the company’s most expansive growth phase (1988-1996) relates how the very circumstances of his career were the vehicle through which he was inwardly transformed. With insight, wit, and colorful anecdotes about life in the world’s leading software company, Kraig Brockschmidt illustrates how one’s career, such as his experience writing the Windows Calculator and his bestselling book, Inside OLE 2, can be a tremendous opportunity for spiritual growth. As he writes, “In the course of my eight and a half years with [Microsoft] I learned and experienced exactly what you would expect from direct [spiritual] training in a monastery or ashram...” Mystic Microsoft thus offers hope to those who feel that their careers are at odds with their inner aspirations and those who seek to find a deeper meaning in their worldly responsibilities.Prologue A Trend Inverted One Homecoming Two Baby Steps Three Pole Shift Four Opportunity Five Leap of Faith Six Esprit de Corps Seven A Bigger Pot Eight A Mile in Their Shoes Nine Only So High Ten Flash Flood Eleven Name, Fame, Guru Game Twelve Purpose Thirteen A Flick of the Switch Fourteen Breakthrough Fifteen Enoughonaire Sixteen Fade to Light Epilogue About the Author Inde

CTL+FO Verification as Constraint Solving

Expressing program correctness often requires relating program data throughout (different branches of) an execution. Such properties can be represented using CTL+FO, a logic that allows mixing temporal and first-order quantification. Verifying that a program satisfies a CTL+FO property is a challenging problem that requires both temporal and data reasoning. Temporal quantifiers require discovery of invariants and ranking functions, while first-order quantifiers demand instantiation techniques. In this paper, we present a constraint-based method for proving CTL+FO properties automatically. Our method makes the interplay between the temporal and first-order quantification explicit in a constraint encoding that combines recursion and existential quantification. By integrating this constraint encoding with an off-the-shelf solver we obtain an automatic verifier for CTL+FO