# An Introduction to Artificial Intelligence Week 7

Course Name: An Introduction to Artificial Intelligence

#### Q1. Which of the following statements is correct regarding Conjunction Normal Form?a. It is a conjunction of disjunction clausesb. It is a disjunction of conjunction clausesc. Empty clause indicates trued. Empty clause indicates false

Q2. Which of the following statements are true, according to the definitions of satisfiability, validity and entailment mentioned in the lectures?
a. S is not valid if ¬S is satisfiable
b. S is valid if ¬S is unsatisfiable
c. S is satisfiable if ¬S is unsatisfiable
d. S is valid if ¬S is not valid

These are An Introduction to Artificial Intelligence Answers Week 7

Q3. Which of the following clauses can be entailed by the given set of clauses?
{(a,¬b, c) , (b, ¬c) , (¬b, c) , (b, c)}

a. (a)
b. (b)
c. (c)
d. ()

Q4. Assume you are running the DPLL algorithm, with MOM’s heuristic on the following CNF formula. What is the next variable to be branched on?
{ (a, ¬b, c) , (¬b, c) , (¬c, d, ¬e) , (¬a, ¬b, e) , (a, ¬b, ¬c) , (d, b) , (e, a) }

a
b
c
d

These are An Introduction to Artificial Intelligence Answers Week 7

Q5. In the previous question, assume that you set your selected variable to True. What is the formula you will obtain after the assignment, followed by repetitively eliminating all unit and pure literals?
a. { (a, c) , (¬c, d, ¬e) , (¬a, e) , (a, ¬c) , (e, a) }
b. { (¬c, d, ¬e) , (d, b) , (e, a) }
c. { (d, ¬e) , (¬a, e) , (a, c) , (e, a) }
d. { }

Q6. Which of the following statements is/are correct about WalkSAT algorithm?
a. The number of clauses satisfied increases by at least one in every move.
b. WalkSAT can detect if the problem is unsatisfiable.
c. It is asymptotically complete.
d. It is sound.

These are An Introduction to Artificial Intelligence Answers Week 7

Q7. GSAT is an example of which of the following:
a. Hill-Climbing with random restarts
b. Random Walk
c. Hill Climbing with random walk
d. Genetic Algorithm

Answer: c. Hill Climbing with random walk

Q8. Which of the following are correct about the soundness and completeness of Resolution (RE) and Forward Chaining (FC) as proof systems for inference in logic?
a. RE is complete.
b. RE is sound
c. FC is complete.
d. FC is sound

These are An Introduction to Artificial Intelligence Answers Week 7

Q9. Which of the following statements are correct about the ontological and epistemological characteristics of First order logic (FOL) and Probabilistic Propositional Logic/Bayesian Networks (BN)?
a. FOL and BN have similar ontology
b. FOL and BN have different ontology
c. FOL and BN have similar epistemology
d. FOL and BN have different epistemology

Q10. Which of the following is an equivalent CNF form of the formula (p -> q) -> (p -> r) ?
a. (p ^ ¬q) V (¬p V r)
b. (¬q V ¬p V r)
c. (¬p V q) ^ (¬p V r)
d. r ^ (¬q V ¬p V r)

Answer: b. (¬q V ¬p V r)

These are An Introduction to Artificial Intelligence Answers Week 7

These are An Introduction to Artificial Intelligence Answers Week 7