FIND INHERENTLY AMBIGUOUS GRAMMAR-

Question

Answer 1

A language is a inherently ambiguous there is not exist any unambiguous grammer.

Ref : https://en.wikipedia.org/wiki/Ambiguous_grammar#Inherently_ambiguous_languages

Now in option (a) , the language generated by this grammer is

L = { a^m bⁿ d^l | m = n} U { a^m bⁿ d^l | n=l} 

let L1 = { a^m bⁿ d^l | m = n} & L2 = { a^m bⁿ d^l | n=l}

So here the language itself there is a conflict requirement for its string. L1 is the set of strings where number of a^'s and b^'s are same while L2  is the set of string where number of b^'s and d^'s are same. Strings of type aⁿ bⁿ dⁿ will have two parse tree.

There is no unambiguous grammar for it. 

Option (b) language generated by this is

L = { a^mbⁿ | n>m } U { (a+b)^* } = (a+b)^*

So for this language you can definitely give unambiguous grammer and even this language is regular and regular language do not posses unambiguity.

S->aS|bS|^ is  unambiguous grammar for it.

Only Grammer given in Option (a) generates inherently ambiguous language

Answer 2

check the grammar,and try to evaluate the grammar ,such a way that it will derive a language in this format {a^nb^nc^m}union {a^nb^mc^m} ,then it will be called inherently ambiguos.Option A will derive language familiar the format which i have given.so Option A is answer.

Comments

FOR THE STRING abb IT GENERATES TWO PARSE TREES,SO IT IS AMBIGUOUS

IF IT IS NOT AMBIGUOUS,THEN HOW TO REMOVE AMBIGUITY FROM THE GRAMMAR THEN ONLY IT IS INHERENTLY AMBIGUOUS GRAMMAR

Answer 3

I think the answer should be both a & b.

In case of a: S->AB->aAbB->abB->abdB->abd

S->CD->aCD->aD->abDd->abd

In case of b:

S->AB->aAbB->abB->abbB->abb

S->CD->aCD->aD->abB->abbB->abb