We study when certain properties of Banach algebras are stable under ultrapower constructions. In particular, we consider when every ultrapower of A is Arens regular, and give some evidence that this is so if and only if A is isomorphic to a closed subalgebra of operators on a super-reflexive Banach space. We show that such ideas are closely related to whether one can sensibly define an ultrapo...

Until recently, punctuation has received very little attention in the linguistics and computational linguistics literature. Since the publication of Nunberg's (1990) monograph on the topic, however, punctuation has seen its stock begin to rise: spurred in part by Nunberg's ground-breaking work, a number of valuable inquiries have been subsequently undertaken, including Hovy and Arens (1991), Da...

Introduction. By a function algebra I shall mean a collection A of complex-valued functions on a set X such that the (pointwise) sum and the product of two functions in A are again in A. We shall always suppose that A contains the constant functions so that A becomes an algebra with unit over the field of complex numbers. A function algebra A is called self-ad joint if the complex conjugate of ...

I n a seminal piece of anthropological research that has quickly become a classic, William Arens examined the credibility of the evidence for the existence of cannibalism as a social phenomenon, and concluded that the evidence was exceedingly weak (Arens, 1979). In fact, he concluded that while cannibalism had undoubtedly occurred in isolated " in extremis " situations, there was no good eviden...

A 1.5‰ to 2‰ carbon isotope shift in surface ocean dissolved inorganic carbon has been reported stratigraphically above the Cretaceous-Tertiary (K-T) boundary in the global stratotype section at El Kef, Tunisia, and in many other marine sections worldwide. Because a change in the dC value of paleoatmospheric CO2 would have accompanied the marine surface carbon isotope shift, the K-T carbon isot...

For given triangular real Lie algebra $\mathfrak{g}$ we construct a certain completion $C^\infty(\mathfrak{g})$ of its universal enveloping algebra. It is Frechet-Arens-Michael algebra, which consists elements polynomial growth and satisfies to the following property: every homomorphism from Banach all whose are has an extension continuous $C^\infty(\mathfrak{g})$. Elements this can be called f...

assume that $a$‎, ‎$b$ are banach algebras and that $m:atimes brightarrow b$‎, ‎$m^prime:atimes arightarrow b$ are bounded bilinear mappings‎. ‎we study the relationships between arens regularity of $m$‎, ‎$m^prime$ and the banach algebras $a$‎, ‎$b$‎. ‎for a banach $a‎$‎-bimodule $b$‎, ‎we show that $b$ factors with respect to $a$ if and only if $b^{**}$ is unital as an $a^{**}‎$‎-module‎. ‎le...

mouse, and speech for input, and audio and screen-based feedback for output. Multimedia presentation. The system makes use of a number of dierent media for human-computer interaction; in particular text, graphics, animation, and prerecorded video (the latter acting as a \cheap", but nevertheless very eective, substitute for in-oce video cameras and/or active badges 3) Communications-oriented ca...