owl - dl. dl system a knowledge base (kb) comprises two components, the tbox and the abox the tbox...

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Page 1: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

OWL - DL

Page 2: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

DL System

• A knowledge base (KB) comprises two components,

• the TBox and the ABox• The TBox introduces the terminology, i.e.,

the vocabulary of an application domain,• The ABox contains assertions about

named individuals in terms of this vocabulary.

Page 3: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

vocabulary

• The vocabulary consists of • concepts, which denote sets of individuals, • and roles, which denote binary relationships

between individuals.• DL systems allow their users to build complex

descriptions of concepts and roles by using atomic concepts and roles

• The TBox can be used to assign names to complex descriptions.

Page 4: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

A DL System

Page 5: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Another representation..

Page 6: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Description Language

• Elementary descriptions are atomic concepts and atomic roles

• Complex descriptions can be built from them inductively with concept constructors

• we use the letters A and B for atomic concepts• the letter R for atomic roles, • and the letters C and D for concept descriptions

Page 7: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of
Page 8: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Examples

Page 9: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Disjoint

• Animal ∏ plant = • Or

• Plant ⊑ animal

Page 10: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

subsumtion

• Tree ⊑ plant

Page 11: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

All values from

• Branch ⊑ Is_part_of.tree

Page 12: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

All values from

• leaf ⊑ Is_part_of.branch

Page 13: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

All values from, role union

• Herbivors=animals ∏ eats.(plant U is_part_of.plant )

Page 14: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Some values from

• Carnivore = animal ∏ eats.animal

Page 15: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

• giraffe = herbivores ∏ eats.leaf

Page 16: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

• Lion=carnivore ∏ eats.herbivore

Page 17: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Tasty_plant = plant ∏ eaten_by.herbivore ∏ eaten_by.carnivore)

Page 18: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Back to DL

Page 19: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

• Suppose that Person and Female are atomic concepts

• those persons that are female

• Those that are not female

• suppose that hasChild is an atomic role,• those persons that have a child

• those persons all of whose children are female

• those persons without a child

Page 20: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of
Page 21: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

• there is a set of objects that are Trees and a binary relation has-branch between objects that leads from a tree to its subtrees. Then the binary trees are the trees with at most two subtrees that are themselves binary trees:

Page 22: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

• A world description (ABox).

Page 23: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

One sort of reasoning• The simplest form of reasoning involves

computing the subsumption relation between two concept expressions,

• i.e., verifying whether one expression always denotes a subset of the objects denoted by another expression.

• Parent is a specialization of Person, i.e., Person subsumes Parent

A

B

Page 24: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Another sort of reasoning

• A more complex reasoning task consists in checking whether a certain assertion is logically implied by a knowledge base.

• For example, Bill is an instance of Parent.

Page 25: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of
Page 26: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Expansion of the family T-Box

Page 27: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of
Page 28: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

ABox

Page 29: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Owl-DL Constructs

Page 30: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Owl-DL Axioms

Page 31: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Reasoning

Page 32: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Inference

Page 33: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of
Page 34: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

DL Inferences

Page 35: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Structural Subsumption

• Normalize descriptions• Compare syntactical structure of normal

forms

Page 36: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Structural Subsumption

Page 37: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Structural Subsumption

Page 38: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Example: Structural Subsumption

Page 39: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

More expressive DLs

Page 40: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of
Page 41: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Negation Normal Form (NNF)

Example

Page 42: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Tableau inferencing

Page 43: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Tableau

Page 44: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Transformation rules

• Example

Page 45: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Example - Tableau Proof

Page 46: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of

Mad Cow Example

Page 47: OWL - DL. DL System A knowledge base (KB) comprises two components, the TBox and the ABox The TBox introduces the terminology, i.e., the vocabulary of