# Abstract Concept

An abstract concept is a concept of a [conceptlogic](../conceptlogic/conceptlogic.md) that represents a other concept of the conceptlogic or of an unspecified extension of the conceptlogic. The concept that is represented by the abstract concept is not necessarily well-defined, while the abstract concept itself is well-defined. There are multiple types of abstract concepts:
- [direct-abstraction](direct-abstraction.md)
- [constructed-abstraction](constructed-abstraction.md)
    - [referenced-abstraction](referenced-abstraction.md)
- [unique-abstraction](unique-abstraction.md)