parser doubt

Question

Consider the statements: (i) Every regular grammar is LL(1) (ii) Every LL(1) grammar is LALR(1) (iii) All LR(0) grammars are LL(k) (iv) A context-free grammar without left factoring and left recursion can be ambiguous Which of the above statement/s is/are TRUE?
(i) only
(i) and (iii) only
(ii) and (iv) only
(iv) only

Comments

yes aambazinga  your ans. is correct. but statement 3.  All LR(0) grammars are LL(k)  why this statement is false

and can you explain why  statement 4 is correct.

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Hmm okay

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@Pavan Shetty

ambiguity and left recursion and left factoring are independent conditions... one doesn't lead to other. hence iv is true.

Answer 1

 only iv is true.

refer this:-

 

Answer 2

(i) Every regular grammar is LL(1)

- No, because regular grammar can be ambiguous/ left recursive/left factored.

(ii) Every LL(1) grammar is LALR(1)

- No, It's opposite.

(iii) All LR(0) grammars are LL(k)

- No, both are different types of parser. LR(0) just need to be unambiguous but LL(1) needs to be unambiguous + Not left recursive + not left factored.

(iv) A context-free grammar without left factoring and left recursion can be ambiguous

- True.