Took, Roger2015-10-052015-10-0519911017-4656https://doi.org/10.2312/egtp.19911021A formal model is presented which combines, in a single structure called a tangle, the power to express both the composition of aggregate objects, and the selective inheritance of object properties over a number of instances or manifestations. The model allows an objective implementation, that is, one in which objects can be created and updated randomly, incrementally, and dynamically. Such a model is ideal as the basis for interactive presentation. The tangle is defined as generic in its node type, and so can model the structure of multiple presentation media.10.2312/egtp.19911021