EXAM

Question 1

A context-free grammar is a recognizer mechanism.

Answer 1

False

Question 2

A rule with both left recursion and right recursion makes the grammar ambiguous.

Answer 2

True

Question 3

EBNF notation allows for a more concise grammar compared to an equivalent grammar in BNF notation.

Answer 3

True

Question 4

The syntax analyzer verifies whether the tokens in a program are correct.

Answer 4

False

Question 5

In a parse tree, the operator with the lowest precedence must appear at the lowest level of the tree.

Answer 5

False

Question 6

A grammar rule with both left recursion and right recursion always generates the same parse tree.

Answer 6

False

Question 7

BNF notation uses curly brackets, i.e. “{“ and “}” symbols, to indicate zero or more repetition of a symbol.

Answer 7

False

Question 8

In a BNF grammar a terminal symbol can be replaced by other symbols.

Answer 8

False

Question 9

To implement left associativity for an operator we use left recursion.

Answer 9

True

Question 10

The static semantics are mostly used to prove the correctness of programs.

Answer 10

False

Question 11

Lexical analysis generates a stream of valid tokens.

Answer 11

True

Question 12

In a DFA, there can be more than one transition out from a state for an input.

Answer 12

False

Question 13

Operational semantics present the meanings of language’s constructs in the form of smaller actions.

Answer 13

True

Question 14

In regular grammars the epsilon symbol is a special non-terminal symbol which can be replaced with another symbol.

Answer 14

False

Question 15

There is only one non-terminal on the RHS of a rule in regular grammars.

Answer 15

True

Question 16

Backtracking parsing algorithms are very efficient in regard with execution time and memory consumption.

Answer 16

False

Question 17

A bottom-up parsing table defines a non-deterministic finite automaton.

Answer 17

False

Question 18

Parsing algorithms build parse trees by finding a derivation for a program.

Answer 18

True

Question 19

In LR parsers, reduce operation means replacing a RHS with its equivalent LHS of a grammar rule.

Answer 19

True

Question 20

Bottom-up parsers perform left-most derivation.

Answer 20

False

Question 21

In a C compiling system, the preprocessor generates the assembly code.

Answer 21

False

Question 22

The variable yytext is the interface between lexical analyzer and syntax analyzer.

Answer 22

False

Question 23

Using C++ for rapid prototyping is more convenient than using python.

Answer 23

False

Question 24

In the grammar rule “turn_off_on : TURN BUILDING ONOFF” we can access the content of TURN using the variable $0.

Answer 24

False

Question 25

In an attributes grammar an intrinsic attribute gets its value from the symbol table.

Answer 25

True

Question 26

In a tail-recursive function, the recursive call is the first to be executed at every iteration.

Answer 26

False

Question 27

In functional programming, a program is not sensitive to the computation history, because it does not need to save information in memory.

Answer 27

True

Question 28

In Racket Language the difference between “for” and “for/list” expressions is that “for/list” returns a list, but “for” does not return anything.

Answer 28

True

Question 29

In Lambda calc, functions have names.

Answer 29

False

Question 30

The racket function (exact? 0.504) returns true.

Answer 30

False

Question 31

An atom in Prolog starts with a capital letter or underscore character.

Answer 31

False

Question 32

We interpret the Prolog rule “Head :- Body” as “If Head is true, then Body is true”.

Answer 32

False

Question 33

In Prolog two compound terms with the same functor can unify no matter how many parameters each one has.

Answer 33

False

Question 34

The underlying computation model in logic programming is Horn clauses.

Answer 34

True

Question 35

In Prolog a fact is a rule which its head is always true.

Answer 35

True

Question 36

The Python and C++ languages implement the same associativity for arithmetic operators.

Answer 36

True

Question 37

A BNF grammar is a generative mechanism.

Answer 37

True

Question 38

Finite Automata are recognizer tools.

Answer 38

True

Question 39

Denotational semantics are specified based on first order logic concepts.

Answer 39

False

Question 40

In Axiomatic semantics, the strongest precondition is the one that is logically implied by all other preconditions.

Answer 40

False

Question 40

The behaviors that can be checked at compile time are generally specified by static semantics.

Answer 40

True

Question 41

An advantage of LR parsers over LL parsers is that less rewriting of grammar rules is required.

Answer 41

True

Question 42

LR parsing algorithms belong to the top-down parsers group.

Answer 42

False

Question 43

Removing left recursion from grammar is desirable when implementing top-down parsing algorithms.

Answer 43

True

Question 44

Rewriting the set of grammar rules on the left side to the set on the right side will change the language defined by the grammar.

S -> E$
E -> T | E -> T
E -> E + T | E -> E + T
T -> 0-9 | T -> 0-9

Answer 44

False

Question 45

Bison generates bottom-up parsers.

Answer 45

True

Question 46

Generally, a compiled source code runs faster than its interpreted counterpart.

Answer 46

True

Question 47

In functional programming, the computation happens through state transitions.

Answer 47

False