Duce, D. A.Ten Hagen, P.J.W.Van Liere, R.2015-10-052015-10-0519891017-4656https://doi.org/10.2312/egtp.19891007This paper was inspired by the Components/ Frameworks approach to a Reference Model for computer graphics, currently under discussion in the ISO computer graphics subject committee. The paper shows how a formal description of the GKS input model may be given in Hoare’s CSP notation and explores some extensions in which some of the components in the GKS model are replaced by more interesting ones. The paper thus demonstrates some of the power and flexibility inherent in the Component/ Frameworks idea. The use of a formal notation led to a deepening of the authors’ understanding of the input model and suggested some different ways of looking at the input model.10.2312/egtp.19891007