Preservation and interpolation results are obtained for L1! and sublog-ics L L1! such that equivalence in L can be characterized by suitable back-and-forth conditions on sets of partial isomorphisms.
This paper investigates the relationships between three different views of common knowledge: the iterate approach, the fixed point approach, and the shared environment approach. We show that no two of these approaches are equivalent, contrary to accepted wisdom. We argue that the fixed point is the best conceptual analysis of the pretheoretic notion, but… (More)
Chu spaces are a new model for information structure (cf. Their properties are usually developed as a form of category theory. In this note, we show how they may also be viewed as models for a two-sorted first-order language, and we determine the exact flow of information across the natural Chu transforms. Our analysis is akin to that of process graphs via… (More)
Patients with idiopathic orthostatic intolerance (IOI) exhibit symptoms suggestive of cerebral hypoperfusion and an excessive decrease in cerebral blood flow associated with standing despite sustained systemic blood pressure. In 9 patients (8 women and 1 man aged 22 to 48 years) with IOI, we tested the hypothesis that volume loading (2000 cc normal saline)… (More)