“ someValuesFrom”和“ allValuesFrom”有什么区别？

Question

In description logic, what is the difference between "someValuesFrom" and "allValuesFrom"? In other words, the difference between (limited existential quantification) and (value restriction).

For example, consider this:

∆ = {a, b, c, d, e}
ext(B) = {<c,d>}
ext(R) = {<a,b>, <a,c>, <d,c>, <c,e>}

So what is the difference between the following?

ext(∃R. B) = ?
ext(∀R. B) = ?

Is there any way to simplify the concept of somevaluefrom and allvaluesfrom?

Answer 1

First, allValuesFrom and someValuesFrom sound like OWL, and they are explained with examples in the specification .

In the context of OWL (which is a DL language) they respresent restrictions on properties, especially on the class of the property values, meaning eg that you want to state that a Car , which has a manufactured_by property, this property is restricted to members of the Class Manufacturer .

allValuesFrom and someValuesFrom differ in the sense, that the first requires all values of the property values, the latter at least one to be of a certain class.