We prove that the modal mu-calculus model-checking problem for (ranked and ordered) node-labelled trees that are generated by order-n recursion schemes (whether safe or not, and w...
We investigate model theoretic characterisations of the expressive power of modal logics in terms of bisimulation invariance. The paradigmatic result of this kind is van Benthemâ€...
Control systems are usually modeled by differential equations describing how physical phenomena can be influenced by certain control parameters or inputs. Although these models ar...
The needs of blind and visually impaired users are seriously under-investigated in CSCW. We review work on assistive interfaces especially concerning how collaboration between sig...
Abstract The advent of large-scale distributed systems poses unique engineering challenges. In open systems such as the internet it is not possible to prescribe the behaviour of al...