25-4-22 2S5 WS21-22

Which of the following statements is false?

• Left as well as right most derivations can be in Unambiguous grammar

• An LL (1) parser is a top-down parser

• LALR is more powerful than SLR

• Ambiguous grammar can’t be LR (k)

Given the following expression grammar:

E -> E * F | F+E | F

F -> F-F | id

which of the following is true?

• * has higher precedence than +

• – has higher precedence than *

• + and — have same precedence

• + has higher precedence than *

Which of the following suffices to convert an arbitrary CFG to an LL(1) grammar?

• Removing left recursion only

• Factoring the grammar alone

• Factoring & left recursion removal

• None of the mentioned

Assume that the SLR parser for a grammar G has n1 states and the LALR parser for G has n2 states.

• n1 is necessarily less than n2

• n1 is necessarily equal to n2

• n1 is necessarily greater than n2

• none of the mentioned

Which of the following describes a handle (as applicable to LR-parsing) appropriately?

• Position where next reduce or shift operation will occur

• The next step has use of Non-terminal for reduction

• Used for reduction in a coming-up step along with a position in the sentential form where the next shift or reduce operation will occur

• Used in the next step for reduction along with a position in the sentential form where the right hand side of the production may be found

Which one of the following is a top-down parser?

• Recursive descent parser

• Operator precedence parser

• An LR(k) parser

• An LALR(k) parser

The grammar A → AA | (A) | e is not suitable for predictive-parsing because the grammar is?

• Ambiguous

• Left recursive

• Right recursive

• An operator grammar

Which of the following suffices to convert an arbitrary CFG to an LL(1) grammar?

• Removing left Recursive alone

• Factoring the grammar alone

• Along with removing left recursion we also perform the factoring of the grammar

• None of the mentioned

What is the grammar for the below equations?

S → C C

C → c C | d

• LL(1)

• SLR(1) but not LL(1)

• LALR(1) but not SLR(1)

• LR(1) but not LALR(1)

Which of the following pairs is the most powerful?

• SLR, LALR

• Canonical LR ,LALR

• SLR canonical LR

• LALR canonical LR