Question

For the grammar below, a partial LL(1) parsing table is also presented along with the grammar. Entries that need to be filled are indicated as E1, E2, and E3. $\epsilon$ is the empty string, $ indicates end of input, and | separates alternate right hand sides of productions.
$S\to aAbB|bAaB|\epsilon$
$A\to S$
$B\to S$

	a	b	$
S	E1	E2	$S\to \epsilon$
A	$A\to S$	$A\to S$	error
B	$B\to S$	$B\to S$	E3

The FIRST and FOLLOW sets for the non-terminals A and B are

• A. FIRST (A) = {a, b, $}
  FIRST (B) = {a, b, $\epsilon$}
  FOLLOW (A) = {a, b}
  FOLLOW (B) = {$}
• B. FIRST (A) = {a, b, $\epsilon$} = FIRST (B),
  FOLLOW (A) = {a, b}
  FOLLOW (B) = $
• C. FIRST (A) = {a, b} = FIRST (B)
  FOLLOW (A) = {a, b}
  FOLLOW (B) = {a, b}
• D. FIRST (A) = {a, b, $\epsilon$} = FIRST (B),
  FOLLOW (A) = {a, b}
  FOLLOW (B) = {a, b, $}

Answer 1

The correct option is D FIRST (A) = {a, b, $\epsilon$} = FIRST (B),

FOLLOW (A) = {a, b}
FOLLOW (B) = {a, b, $}
$S\to aAbB|bAaB|\epsilon$
$A\to S$
$B\to S$
First of S = {a, b, $\epsilon$}
First of A = {a, b, $\epsilon$}
First of B = {a, b, $\epsilon$}
Follow of S = {$\$,a,b$}
Follow A = {b, a}
Follow of B = {$, a, b}