3.4 Static and dynamic structures
An article followed by a noun provides information whether that sentence is dynamic or static. A definition sentence is static and has an indefinite article. However, a dynamic structure has a definite article and can change over time, like in the situation “Bush is the president of the USA.” has changed when Obama was elected: “Bush was the president of the USA.” and “Obama is the (current) president of the USA.”. So, a changed situation can influence other knowledge as well. Only the knowledge that is associated with the changed information, might change too. This mechanism is an important characteristic of natural language. And it is used extensively in providing programming in natural language. See: 3.10 Bridging the gap between natural and programming language.
Using mechanisms like this, makes it possible to implement techniques with a deeper level of “understanding” than traditional ontology, NLP and Question Answering techniques.