Ch 5

Question 1

Which of the following programming languages most closely follows the stored program concept?

Answer 1

C

Question 2

Prolog is based on…

Answer 2

Predicate logic

Question 3

There are three kinds of clauses in a Prolog program: facts, rules and goals.

Answer 3

A fact can be considered a special case of a rule.

Question 4

What mechanism cannot be used for passing values between clauses within a Prolog rule?

Answer 4

Return value

Question 5

If you want to pass multiple values out of a Prolog rule, which of the following methods is valid?

Answer 5

Use multiple named variables to hold the values.

Question 6

A goal clause and a fact unify, if…

Answer 6

their predicates are the same,
their arities are the same,
and
their corresponding arguments match.

Question 7

The arity of a predicate is…

Answer 7

the number of arguments of the predicate.

Question 8

The scope of a Prolog variable is within…

Answer 8

a single rule.

Question 9

A circular definition of a Prolog rule…

Answer 9

will cause a dead loop when no match can be found.

Question 10

An anonymous variable in Prolog is a…

Answer 10

placeholder.

Question 11

What is the output when the following Prolog goal is executed?
?-member(apple, [orange, apple, pearl]).

Answer 11

true?

Question 12

Assume we have the following fact in a Prolog factbase:
child_of(mary, [amy, david, conrad]).

What is the output when the following Prolog goal is executed?
?- child_of(mary, [amy | T]).

Answer 12

T = [david, conrad]

Question 13

Assume that we have the following fact in a Prolog factbase:
child_of(mary, [amy, david, conrad]).

What is the output when the following goal is executed?
?- child_of(mary, [amy | [H | [conrad]]]).

Answer 13

H = david

Question 14

What is the output when the following Prolog goal is executed?
?- member(X, [81, 25, 9, 29,]), Y is X*X, Y<400.

Answer 14

X = 9 Y = 81

Question 15

Given the following recursive rules in Prolog:
foo(X, [X]).
foo(X, [ _ | T]) :- foo(X, T).

The rules find…

Answer 15

whether an element is a member of a list.

Question 16

When Prolog is searching for possible matches and a cut “!” is encountered,

Answer 16

all existing backtrack points will be removed.

Question 17

What does the built-in predicate cut (!) do?

Answer 17

Remove all existing backtracking points.

Question 18

What does the built-in predicate fail do?

Answer 18

Return false.

Question 19

The built-in Prolog predicate repeat always…

Answer 19

succeeds and adds a backtracking point.

Question 20

What does the following code do?
go :- repeat, get(X), write(X), nl, fail.

Answer 20

It takes a character from the keyboard, prints it, and exits if the character is NOT printable.

Question 21

What is the key difference between the semantic web and the syntactic web?

Answer 21

Semantic web better supports automatic processing and integration of web information.

Question 22

How is Prolog related to the semantic web?

Answer 22

Prolog is frequently used for writing the parsers of the semantic description language.