UML is an acronym for Unified Modelling Language. It has become de facto the standard for the object-oriented software analysis and design stages in software development. UML is a visual modelling language, and it consists of a set of diagrams. Static diagrams are used to depict static structure of a program, where is dynamic diagrams specify how the control flow(s) of the program should behave. The examples of behavioral diagrams are a Sate diagram, which describes the behavior of objects of a given class, and a Sequence diagram, which describes inter-object interactions in a given scenario. A ...

This thesis starts by exploring background areas of study such as incomplete and uncertain information in relational database, belief change in artificial intelligence. It also reminds of how some types of incompleteness and uncertainly can be modeled through disjunctive databases. The paper describes the language being used in addition to some update operators. This thesis then brings to light a new theory in belief change called the weak revision. It first shows the need for such a new operator through a real life example. Second it introduces this new operator by defining its general behavior. ...