An atomic object in LINCKS is represented by two kinds of nodes see figure 2 : versions and a history structure node.
Versions represent the actual appearances of objects at certain times. The history structure nodes contain object information and historical information of the objects. The historical information is represented by different partial orders (see section 2.6, 2.7 and 8).
A node has the following distinct parts
Nodes are identified by unique node identification numbers. An object is then identified by the node identification number of its history structure node. A particular version of an object is identified by a pair of node identification numbers: the object identifier and the node identification number of the actual version. These node identifiers are unique with respect to the database. However for each session only the nodes which are reachable can be brought into the workspace. For reasons of information hiding the nodes receive a local identification number, very likely different in each session, which is mapped to the database node identification number using an interface table. This will also allow us in the future to implement easily disconnected workspaces on portable computers.
LINCKS supports both dynamically bound links and statically bound links (see figure 2). The dynamically bound link is a link between a version of an object and another object. The binding of the target object to a particular version of that object occurs on demand. Thus it is not necessary to introduce new links every time the target object changes. The version referenced by a dynamically bound link is time dependent and is in LINCKS by default the most recent version of that object. It is however possible for the user to interactively specify the desired version. In contrast to dynamically bound links one can also have statically bound links which link directly to a particular version of an object and do not require any further resolution.