CS 462 TEST # 2

Deadline: E-mail by Monday 11 p.m., April 21, 2008.

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Please remember that everybody must work independently.
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Problem 1:  Apply the idea of explanation-based learning to identify 1 or 
2 new operators (rules) to improve the search efficiency of the N-puzzle 
problem. Incorporate the new rules into the code, and show experimental
results demonstrating their effect on the length of the shortest path.
Explain the results.

Problem 2:  Consider a world in which there are only four propositions,
A, B, C and D. How many models are there for the following sentencies?

	a.)     A & B
	b.)     A V B
	c.)     A & B & C

Problem 3:  Truth tables are used to establish the validity of complex
sentencies. Show how they can be used to decide if a sentence is valid,
satisfiable, or unsatisfiable. Also, show how they can be used to 
demonstrate the soundness of inference. Use the Modus Ponens rule as an
example. Discuss the complexity of propositional inference, and compare 
it to the complexity of FOL.

Problem 4:  Write down logical representations for the following 
sentencies, suitable for use with the Generalized Modus Ponens.

	a.) Horses,cows, and pigs are mammals.
	b.) An offspring of a horse is a horse.
	c.) Bluebeard is a horse.
	d.) Bluebeard is Charlie's parent.
	e.) Offspring and parent are inverse relations.
	f.) Every mammal has a parent.

Problem 5:  You are hired to build a KBS for someone who is not familiar 
with this type of systems, but believes that a KBS is a good solution for 
his/her problem. As a knowledge engineer, your first task is to find
out how suitable the problem domain for such an application.Explain how 
you will do that (i.e. how to distinguish between "good/bad" or 
"suitable/unsuitable" domains). Explain what the ontological engineering 
is. Explain the difference between "shallow" and "deep" knowledge, and 
between "diagnostic" and "model-based" KBSs. Give examples to illustrate your
answer.