Comment on Clark and Bremner

on semihypergroups and hypergroups

in this thesis, first the notion of weak mutual associativity (w.m.a.) and the necessary and sufficient condition for a $(l,gamma)$-associated hypersemigroup $(h, ast)$ derived from some family of $lesssim$-preordered semigroups to be a hypergroup, are given. second, by proving the fact that the concrete categories, semihypergroups and hypergroups have not free objects we will introduce t...

Clark Glymour

Twenty years ago, Nancy Cartwright wrote a perceptive essay in which she clearly distinguished causal relations from associations, introduced philosophers to Simpson’s paradox, articulated the difficulties for reductive probabilistic analyses of causation that flow from these observations, and connected causal relations with strategies of action (Cartwright 1979). Five years later, without appr...

Katerina Clark

Lens Lectures on Aleksandrov-clark Measures

In this series of three 90 minute lectures I will give a gentle introduction to the topic of Aleksandrov-Clark measures which turn out to have an uncanny way of appearing in various areas of analysis. In short, for an analytic map φ : D→ D, where D is the open unit disk, there is a family {μα : |α| = 1} of positive finite measures on the unit circle T associated with φ by the formula 1− |φ(z)|2...

Reconsidering Clark

The use of Herbert Clark’s work as a theoretical framework in the Computer Supported Collaborative Work domain is often dismissed or judged as “cooked” and led to a large body of controversy. This article intends to reconsider his contribution and re-examined the criticisms he received. The main critics addressed to Clark are that his notion of Common Ground is far too mentalist and lacks “situ...