FLAT:Objective test

Recursively enumerable languages are referred as

• Type 0

• Type 1

• Type 2

• Type 3

Correct hierarchical relationship among context- free, right-linear, and context-sensitive language is

• context-free ⊂ right-linear ⊂ context-sensitive

• context-free ⊂ context-sensitive ⊂ right-linear

• context-sensitive ⊂ right-inear ⊂context-free

• right-linear ⊂context-free ⊂context-sensitive

Following context free grammar

S —> aB | bA

A —>b | aS | bAA

B —> b | bS | aBB

generates strings of terminals that have

• equal number of a's and b's

• odd number of a's and odd number b's

• even number of a's and even number of b's

• odd number of a's and even number of a's

Which of the following statement is correct?

• All languages can not be generated by CFG

• Any regular language has an equivalent CFG

• Some non regular languages can't be generated by CFG

• both (b) and (c)

Language of finite automata is.

• Type 0

• Type 1

• Type 2

• Type 3

The context-free languages are closed for:

(i) Intersection (ii) Union

(iii) Complementation (iv) Kleene Star

• (i) and (iv)

• (i) and (iii)

• (ii) and (iii)

• (ii) and (iv)

The language accepted by a Push down Automata:

• Type 0

• Type 1

• Type 2

• Type 3

1. A CFG is ambiguous if

• It has more than one rightmost derivations

• It has more than one leftmost derivations

• No parse tree can be generated for the CFG

• None of the mentioned

A language that admits only ambiguous grammar:

• Inherent Ambiguous language

• Inherent Unambiguous language

• Context free language

• Context Sensitive language

A symbol X is called to be useful if and only if its is:

• generating

• reachable

• both generating and reachable

• none of the mentioned