Dexter Kozen and Bernhard Möller. Separability in Domain Semirings. Technical Report 2004-16, Universität Augsburg, Institut für Informatik, December 2004.

First, we show with two examples that in test semirings with an incomplete test algebra a domain operation may or may not exist. Second, we show that two notions of separability in test semirings coincide, respectively, with locality of composition and with extensionality of the diamond operators in domain semirings. We conclude with a brief comparison of dynamic algebras and modal Kleene algebras.