J.I. den Hartog and E.P. de Vink
Building Metric Structures with the Meas-Functor

We introduce the functor~$\Meas$ in the category of complete
ultra metric spaces and nonexpansive mapping. The main result 
of this paper is that $\Meas$ is a welldefined and locally 
nonexpansive endofunctor. Therefore the functor fits naturally 
in the metric approach to programming language semantics.
The use of $\Meas$ in the construction of probabilistic
powerdomains, either directly or through the use of domain 
equations, is illustrated with two examples.