Classes are interpreted as sets that contain individuals.
Individuals represent objects in the domain that we are interested in.
Properties are binary relations on individuals - i.e. properties link two individuals together.
Creating clases
Concept: Disjointness
All classes could potentially overlap: This means an individual could be both a Pizza and a Ice Cream at the same time.
If we state that classes are disjoint: This means an individual cannot be both a Pizza and a Ice Cream at the same time.
Creating Properties
Concept: Characteristics of properties
If a property is functional, for a given individual, there can be at most one individual that is related to the individual via the property.
If some property links individual a to individual b then its inverse property will link individual b to individual a.
Concept: Characteristics of properties
If a property is transitive, and the property relates individual a to individual b, and also individual b to individual c, then we can infer that individual a is related to individual c via property P.
If a property P is symmetric, and the property relates individual a to individual b then individual b is also related to individual a via property P.
Creating Conditions
Concept: Characteristics of conditions
AllValuesFrom: All values of the property must be of a certain type.
SomeValuesFrom: At least one value of the property must be of a certain type.
Concept: Characteristics of conditions
HasValue: At least one of the values of the property is a certain value.
Cardinality: The property must have at least/at most/exactly x values.