Solution
The correct answer is 5
Explanation:
To determine how many items will be in the set for GOTO(I0, $) given the grammar:
Grammar:
1. S → A
2. A → $B$
3. A → id
4. B → B, A
5. B → A
Step 1: Compute the CLOSURE of I0 = CLOSURE({[S → .A]})
The initial item set I0 consists of the item [S → .A] .
Applying the Closure:
1. From S → .A , we look for productions for A :
A → $B$
A → id
So, we add:
[A → $B$]
[A → id]
2. We also have B productions, since B can be derived from A :
B → B, A
B → A
Thus, the closure will contain the following items:
- [S → .A]
- [A → $B$]
- [A → id]
- [B → B, A]
- [B → A]
Closure Result:
- So, I0 = {[S → .A], [A → $B$], [A → id], [B → B, A], [B → A]} contains 5 items.
Step 2: Compute GOTO(I0, $)
Now we compute GOTO(I0, $) .
For each item in I_0 :
1. Item: [S → .A]
This item has the dot before A , and since we are doing GOTO(I0, $) , we look for a production that has A followed by a $.
2. Item: [A → $B$]
This item is already at $, and it does not produce anything new.
3. Item: [A → id]
This item does not contain any $.
4. Item: [B → B, A]
This item does not contain any $.
5. Item: [B → A]
This item does not contain any $.
The only transition will happen from the first item:
- From [S → .A] to [S → A.] if we were to look at it followed by $ but as we are considering directly into GOTO to $ it will transition to the completion of handling B .
Conclusion for GOTO(I0, $) :
- After considering all items:
- The item resulting from [S → .A] will yield [S → A.] which finalizes based on A and only B transitions over.
Resulting Items in GOTO Set:
- Thus we gather:
- [S → A cdot]
- [A → $B$]
- [A → id]
- [B → B, A]
- [B → A]
This retains the closure set yet leading us to assess from the transitions that all items still remain as is thus maintaining a total of 5 items.
Final Answer:
The correct answer is 3) 5.