Given grammar G:S->aS| ABA-> eB-> eD-> bReduce the grammar, removing all the e productions:
Question
Given grammar G:S->aS| ABA-> eB-> eD-> bReduce the grammar, removing all the e productions:
Solution 1
The given grammar is:
G: S -> aS | ABA
A -> e
B -> e
D -> b
The first step in removing the e productions (also known as epsilon productions) is to identify the nullable variables. A nullable variable is a variable that can generate the empty string. In this case, A and B are nullable variables because they both produce e.
Next, we need to modify the grammar by removing the e productions and adding new productions for each combination of nullable variables in the right-hand side of the original productions.
The modified grammar is:
G: S -> aS | aA | aB | a | ABA | AB | AA | A | BA | B | A |
A ->
B ->
D -> b
In the new grammar, we have removed the e productions and added new productions for each combination of nullable variables in the right-hand side of the original productions. For example, the original production S -> aS has been replaced with four new productions: S -> aS, S -> aA, S -> aB, and S -> a. This is because S could be replaced with any combination of A and B, which are both nullable variables.
Finally, we remove any productions that have become useless. In this case, the productions A -> and B -> are useless because they do not produce any terminals, so we can remove them. The final grammar is:
G: S -> aS | aA | aB | a | ABA | AB | AA | A | BA | B | A |
D -> b
Solution 2
The given grammar is:
G: S -> aS | ABA
A -> e
B -> e
D -> b
The first step in removing ε-productions is to identify the nullable variables. A nullable variable is a variable that can generate the empty string ε. In this case, A and B are nullable variables because they directly produce ε.
Next, we need to modify the grammar by removing the ε-productions. We do this by replacing each occurrence of a nullable variable on the right side of a production with ε. However, we need to be careful to maintain the language generated by the grammar.
For each production that contains a nullable variable, we add a new production where we remove the nullable variable. We do this for all combinations of nullable variables in the production.
The modified grammar becomes:
G: S -> aS | a | AB | A | B | ε
A -> ε
B -> ε
D -> b
Finally, we remove the ε-productions A -> ε and B -> ε to get the final grammar:
G: S -> aS | a | AB | ε
D -> b
This is the reduced grammar with all ε-productions removed.
Similar Questions
Given grammar G: S->aS| AB A-> e B-> e D-> b Reduce the grammar, removing all the e productions: ans. None of the mentioned S->aS| AB| A| B S->aS| AB| A| B| a, D-> b S->aS| AB| A| B, D-> b
S→ aB/abA→aAB/aB→ABb/bIs the given grammar G a context-free grammar? Justify your answer with anexplanation. Additionally, using the string "aaaabbbb," determine if the grammar G isambiguous or not by analysing its production rules and derivation.
For the grammar E -> E + E | E * E | a, select all leftmost derivations for the string a+a*a1 pointE => E + E => E + E * E => E + E * a => E + a * a => a + a * aE => E + E => E + E * E => a + E * E => a + a * E => a + a * aE => E * E => E + E * E => E + E * a => E + a * a => a + a * aE => E * E => E + E * E => a + E * E => a + a * E => a + a * a
Consider the following grammar G G: S → EF E → a|∈F → abF|ac Which of the following is true about the grammar G?1. G is a LL(1) grammar2. G is a regular Grammar 1 only2 only1 and 2 bothNone of these
Which regular grammar generates the language consisting of strings containing "aba" or "abb"? Options : S -> a | b | aS | bS S -> abS | abbS | ε S -> abaS | abbS | ε none
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.