Predicate completion is an approach to closed world reasoning which assumes that the given sufficient conditions on a predicate are also necessary. Circumscription is a formal device characterizing minimal reasoning i.e. reasoning in minimal models, and is realized by an axiom schema. The basic result of this paper is that for first order theories which are Horn in a predicate P, the circumscri...

The ubiquitin-proteasome system targets numerous cellular proteins for degradation. In addition, modifications by ubiquitin-like proteins as well as proteins containing ubiquitin-interacting and -associated motifs modulate many others. This tightly controlled process involves multiple specific and general enzymes of the system as well as many modifying and ancillary proteins. Thus, it is not su...

Over the last fifteen years, we have built over a dozen different applications in many domains where the user can define behaviors by demonstration. In some of these, the system uses sophisticated artificial intelligence (AI) algorithms so that complex behavior can be inferred from a few examples. In other systems, the user must provide the full specification, and the examples are primarily use...

We describe a simple model of how a publication’s citations change over time, based on pure-birth stochastic processes with a linear cumulative advantage effect. The model is applied to citation data from the Physical Review corpus provided by APS. Our model reveals that papers fall into three different clusters: papers that have rapid initial citations and ultimately high impact (fast-hi), fas...