This paper presents the TPCALP framework, a theorem-proving approach which aims to unify Abductive Logic Programming (ALP), Constraint Logic Programming (CLP) and Semantic Query Optimization (SQO). The framework combines the use of deenitions, as in ordinary logic programming, with the use of integrity constraints, as in ALP and SQO. The programmer can… (More)
Preamble The Large Observatory for X-ray Timing, LOFT, is specifically designed to perform fast X-ray timing and spectroscopy (Feroci et al. 2014). LOFT focuses on two fundamental questions from ESA's Cosmic Vision Theme: what is the equation of state of ultra-dense matter in neutron stars and does matter orbiting close to the event horizon follow the… (More)
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Transient and variable objects have played a major role in astronomy since the Chinese began to observe them more than two millennia ago. The term nova, for example, traces back to Pliny. Tycho's determination that the parallax of the supernova of 1576 was small (compared to a comet) was important in showing the Universe beyond the Solar System was not… (More)
The first results from a near-contemporaneous optical and infrared spectro-scopic observing program designed to probe the detailed density structure of classical Be circumstellar disks are presented. We report the discovery of asymmetrical infrared emission lines of He I, O I, Fe II, and the Brackett, Paschen, and Pfund series lines of H I which exhibit an… (More)