Presencelabsence data for the small-mammal species at sites in seven deserts were analyzed for evidence of similarity in community structure. The deserts studied were located in North and South America (268 and 118 sites, respectively), Australia (245 sites), Israel (54 sites), and greater Eurasia (Thar, 15 sites; Turkestan, 36 sites; Gobi, 98 sites). Patterns observed in all deserts included: ...

The formal expression of pro positional attitudes, especially when nested (iterated), is an important problem for A I . An interesting first-order extensional logical system for such expression has been proposed by Creary. In this system concepts (and concepts of concepts, etc.) are made explicit. The system includes "concept functions", which are special functions which act on and deliver conc...