Interleaved contractions

We study an approach to concurrent contractions, that is, to simultaneous contractions performed by multiple agents. Using ideas from the semantics of programming we adopt an interleaved approach to reason about concurrent contractions. Although many of the notions from the traditional G ardenfors approach transfer to this setting, our approach also forces us to depart from the Gardenfors framework in important ways. We present laws describing rational concurrent contractions, as well as a construction that satis es these laws.