10: Logic and Inference Rules Flashcards Preview

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Flashcards in 10: Logic and Inference Rules Deck (34)
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1
Q

Why is DL (Descriptive Logic) used in AI (Artificial Intelligence)?

A

To describe and reason about the relevant concepts of an application domain (known as terminological knowledge)

2
Q

In intelligent systems, knowledge needs to be ____, ____, and ____.

A

In intelligent systems, knowledge needs to be captured, communicated, and processed.

3
Q

Agents are ____ and have their own ontology and ____ with one another through such systems.

A

Agents are autonomous** and have their own ontology and **communicate with one another through such systems.

4
Q

On what two components are DL’s knowledge representation systems based?

A
  • TBOX
  • ABOX

note: T stands for terminology and A stands fo assertion

5
Q

What is the difference between “some” (∃) and “only” (∀)?

A
  • only” is about closure and closes off extra options
  • some” does not
6
Q

Assuming T is a top concept, translate the following to English:

Parent≡∃parentOf.T

A

Persons who are parents

7
Q

Assuming T is a top concept, translate the following to English:

∃parentOf.Female

A

Persons who have some daughter(s)

8
Q

Assuming T is a top concept, translate the following to English:

∀parentOf.Female

A

Those who are the parents of only daughters, if any

9
Q

Assuming T is a top concept, translate the following to English:

(∀.parentOf.Female)∩∃parent.Female

A

Those who are the parents of only daughters

10
Q

Write the DL equivalent of the following Protege statement:

ParentOf Some Female

A

∃parentOf.Female

11
Q

Write the DL equivalent of the following Protege statement:

ParentOf Only Female

A

∀parentOf.Female

12
Q

Write the DL equivalent of the following Protege statement:

hasGivenName value “Matthew”

A

∃hasGivenName. {Matthew}

13
Q

Assume you have 3 classes of Team, Player, and Position. Also, assume you have 2 properties of employs and plays:

team1 employs player1

player1 plays position1

Write a descriptive logic statement in Protege that returns the teams which have employed at least 3 players who play as striker or rightBack position.

A

Team and employs min 3 (Player and hasPosition some {striker, rightBack})

14
Q

Translate the following to a descriptive logic statement:

You have a class DogLike and you intend to state that if something runs like a Dog and smells like a Dog, then it is in DogLike class.

A

((runsLike some Dog) and (smellsLike some Dog)) SubClassOf DogLike

15
Q

In a nutshell, in a General Class Axiom, you say things about complex descriptions of entities without using any ____.

A

In a nutshell, in a General Class Axiom, you say things about complex descriptions of entities without using any naming.

16
Q

What will the Debugger prevent if you add the following statement to General Class Axiom?

Disease and (causedBy some A) SubClassOf: (hurts only B)

A

The Debugger will prevent inconsistency by not allowing a disease caused by some A to hurt somewhere outside B

17
Q

Assume three colors:

Colors:{red, white, blue}

And in the set Flower, each flower can have one or more color(s). The following DL query:

Flower and hasColor value red

does return any flower with red color but NOT every flower with ONLY red color. Even changing it to

Flower as (hasColor only {red})

does not solve the problem. Why is this?

A

Because OWL uses the open world assumption.

If we know that a flower has a red color, it does not mean that it does not have other colors, e.g. it can have other colors in the dataset.

18
Q

Logic helps in the challenging task of representing knowledge in www in a consistent and uniform manner so that it is ____ ____ to humans and ____ ____ by machines.

A

Logic helps in the challenging task of representing knowledge in www in a consistent and uniform manner so that it is easily comprehensible to humans and effectively inferable by machines.

19
Q

Descriptive Logic (DL) helps us to build ____ ____ from atomic concepts.

A

Descriptive Logic (DL) helps us to build complex concepts from atomic concepts.

20
Q

In DL, a domain can be described in terms of different classes, properties, and instances.

In this way, DL can facilitate generating answers to queries through ____ ____, improving future semantic search engines.

A

In this way, DL can facilitate generating answers to queries through logical reasoning, improving future semantic search engines.

21
Q

What is the intersection of Horn Logic and OWL called?

A

DLP (Description Logic Program)

22
Q

Fill in the blanks of the DLP diagram.

A
23
Q

What are the equivalent terms in Description Logic for the following OWL terms?

class, property, Object

A
  • class = concept
  • property = role
  • Object = individual
24
Q

What is the importance of logic?

A
  • high-level language for expressing knowledge
  • high expressive power
  • well-understood formal semantics
  • precise notion of logical consequence
  • proof systems that can automatically derive statements syntactically from a set of premises
25
Q

The languages of RDF and OWL can be viewed as ____ of predicate logic (first order logic).

A

The languages of RDF and OWL can be viewed as specializations of predicate logic (first order logic).

26
Q

Predicate logic and its special cases are ____, in the sense that, if a conclusion can be drawn, it remains valid even if new knowledge becomes available.

A

Predicate logic and its special cases are monotonic, in the sense that, if a conclusion can be drawn, it remains valid even if new knowledge becomes available.

27
Q

How is a rule represented in Horn Logic?

A

A1, …, An -> B

28
Q

Deductive Rules

(Horn Logic)

A

If A1, …, An are known to be true, then B is also true

29
Q

Reactive Rules

(Horn Logic)

A

If the conditions A1, …, An are true, then carry out the action B

30
Q

Description Logic vs Horn Logic

A
  • Neither of them is a subset of the other
  • Impossible to assert that a person X who is a brother of Y is uncle of Z (where Z is child of Y) in OWL
    • But using rules, it can be represented as brother(X, Y), childOf (Z, Y) -> uncle (X, Z)
  • On the other hand, rules cannot assert the information that a person is either a man or a woman
    • In OWL, this can be expressed using a disjoint union
31
Q

Give an example of a chain of properties using circle notation.

A
  • hasGrandParent is a chain of properties of hasParent o hasParent
  • hasSibling is a chain of properties of hasParent o hasChild
32
Q

Assuming you have hasParent, hasSister, hasSibling, hasBrother, and hasChild properties, build the concept of a cousin based on the chain of properties through defining hasCousin.

A

hasCousin is a chain of properties of

hasParent o hasSibling o hasChild

33
Q

Give a monotonic and a non-monotonic rule for the following:

An online vendor wants to give a special discount if it is a customer’s birthday.

A
  • Monotonic: If birthday, then special discount
  • Non-monotonic: If birthday is not known, then not special discount
    • Applicable when available information is incomplete
34
Q

The Semantic Web approach is to express the knowledge in a ____ way using one of the Web languages already discussed.

A

The Semantic Web approach is to express the knowledge in a machine-accessible way using one of the Web languages already discussed.