Knowledge Engineering ​
TBox
What exists. Defines a domain of interest by defining classes of properties as a domain vocabulary.
ABox
What it does. Assertion component. Facts associated with the TBox conceptual model.
This is a diagram of how this system is used. A knowledge base contains both a TBox and a ABox:
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AL ​
- Description logics usually a subset of First order logic (FOL), and each support different concept and role constructs
- The simplest DL is AL
| Construct | Syntax | Example | FOL |
|---|---|---|---|
| Atomic concept | A | Sandwich | sandwich(x) |
| Atomic role | P | hasIngredient | hasIngedient(x,y) |
| Atomic negation | ~A | ~Sandwhich | ~sandwich(x) |
| Conjunction | C n D | Cheese n Veggie | sandwhich(x) n food(x) |
| Existential quantif. | E R.C | E hasIngredient.Veggie | E y (hasIngredient(x,y) n Veggie(y)) |
| Value restriction | V R.C | V hasIngredient.Veggie | V y (hasIngredient(x,y) ⇒ Veggie(y)) |
ALC ​
Popular DL that expands AL with full negation.
Knowledge Representation ​
ways of representing knowledge:
- logic based
- graph based
- frame based