Propositions are Abstract entities that express a complete thought or a set of such thoughts. As an example, the formula '(instance Yojo Cat)' expresses the Proposition that the entity named Yojo is an element of the Class of Cats. Note that propositions are not restricted to the content expressed by individual sentences of a Language. They may encompass the content expressed by theories, books, and even whole libraries. It is important to distinguish Propositions from the ContentBearingObjects that express them. A Proposition is a piece of information, e.g. that the cat is on the mat, but a ContentBearingObject is an Object that represents this information. A Proposition is an abstraction that may have multiple representations: strings, sounds, icons, etc. For example, the Proposition that the cat is on the mat is represented here as a string of graphical characters displayed on a monitor and/or printed on paper, but it can be represented by a sequence of sounds or by some non-latin alphabet or by some cryptographic form.
||MathematicalModel||A model that uses the mathematical aparatus|
| ||Multipole||Basic element of a multipole diagram, a multipole is a model of a component of a dynamic system, it can model a real separable component, such as a motor of a vehicle, or just an attribute of the system, such as inertia or friction, multipole interacts with other multipoles through its poles.|
| ||MultipoleModel||Model of a physical system consisting of mutually interconnected multipoles.|
| ||MultipolePole||A part of multipole pole that models a single energetical interaction. If a pole belongs to a multipole, it also belongs to one of its sections.|
| ||MultipoleSection||A set of poles that is subject to the postulate of continuity. A multipole may consist of one or more sections. Sections of a single multipole do not overlap and cover all its poles.|