Question

Solve the following questions. All questions are mandatory.

Q1: What’s wrong in the following grammar?

S → ABC

A → aA|aa

B → bB|B

C → cC|cccc

Q2: Describe the strings generated by the following grammar

S → aSa

S → bSb

S → aa

S → bb

Q3: Consider the following grammar:

S → ABC

A → aA|a

B → bB|b

C → cC|c

Change the above grammar such that it generates L1={aⁿb^mc^k; n>=3,m>=3,k>=4}

Q4: Use the following grammar to show a rightmost derivation for the following statement: A = A * ( B + ( C ) )

<assign> → <id> = <expr>

<expr> → <id> + <expr> | <id> * <expr> | ( <expr> ) | <id>

<id> → A | B | C

Q5: Prove that the following grammars are ambiguous:

G1:

<stmt> → X|Y|e|<stmt><stmt>

G2: <start> → <first>

<first> → <first> + <first> | <second>

<second> → A | B | C

Q6: Rewrite the following BNF to give + precedence over * and force + to be left associative.

<assign> → <id> = <expr>

<expr> → <term> + <expr> | <term>

<term> → <id> * <term> | <id>

<id> → A | B | C

Answer 1

5) any grammar that produces more than treone parse tree for any input then it is ambiguous.