Nodes, Links and Anchors in the Tower Model

In the tower model, a node is described by a value and is identified (by object-identification / oid). Anchor and link are also described by an object-identification and a value. However, link is described not only by an object-identification and a value, but also by a source anchor, and a destination anchor. In the tower model, nodes, links and anchors are known as first-class citizens, they have object-identifications and values.

Objects can be nodes, links or anchors. Their values can be basic values, composite values, tower values or city values.

In a node, the link's endpoint location is represented by a basic anchor. While a basic link is a simple relationship between two basic anchors.

Composite Objects in the Tower Model

Composite object in the tower model is a collection of objects into one higher order object. Simpler information objects are combined together and construct a more complex object.

Thus, a composite object is an object with a composite value, which itself consists of a composite constructor, a set of nodes, a set of links and a set of anchors.

A composite constructor consists of:

• a kind of the object (node, link or anchor);
• a set of components (set of nodes, links and anchors);
• a structure constructor;
• a set of locations of the components;
• a set of global constraints;
• global information.