In Integral Relational Logic, generalization hierarchy indicates ‘kind-of’ relationships between classes of entities, as universals, like a taxonomy.

To give a simple example, subclasses of the class Quadrilateral can be depicted in a diagram like this:

To illustrate the two fundamental ways of organizing our ideas in Integral Relational Logic, here is much the same information arranged as a relation. Notice that attributes can be classified in various ways, such as defining and identity, which is name in this instance, utilizing the fundamental principles of concept formation.

*Note. These are British terms, using the words trapezium and trapezoid in the original meanings given by Proclus in the fifth century. In the late eighteenth century, the meanings of these two words were confusingly transposed, and they still are in the USA. In American English, a trapezium is a trapezoid and a trapezoid is a trapezium.