The difficulty is to find a good description language in which to express the learning situation.
For this reason, the description languages used in artificial intelligence do not usually include' *'.
Here is an example of an optimal description language.
Whether we regard a concept as ontological or simple depends on our choice of description language.
From a theoretical point of view, research on models seeks for general results, independent of any particular description language.
To define the Kolmogorov complexity, we must first specify a description language for strings.
Metafont is a description language used to define vector fonts.
Whether these description languages are the best possible for the job, and whether they will become/remain the favorites in the future, remain open questions.
The inference rules are commonly specified by means of an ontology language, and often a description language.
It depends critically on the description language.