Test by Bikram | Compiler Design | Test 1 | Question: 6

Question

Consider the following grammars:
$Z \rightarrow  TZ'$
$Z' \rightarrow ^* TZ' \mid \epsilon$
$T \rightarrow  YT'$
$T ' \rightarrow ^*YT '  \mid \epsilon$
$Y \rightarrow (Z) \mid id$

 

Which of the following is First(Z)?

• A. $\{T, ) \}$
• B. $\{(, id \}$
• C. $\{ ), \$ \}$
• D. None of the above

Answer 1

$$\begin{array}{|l|l|l|l|} \hline  & \textbf{First} & \textbf{Follow} \\ \hline Z\rightarrow TZ' &  \{(,id\} &  \{\$,)\} \\ \hline Z'\rightarrow \ast TZ' \mid \epsilon & \{\ast,\epsilon\} & \{\$,)\}  \\ \hline T\rightarrow YT'& \{(,id\} & \{\ast,$,)\}  \\ \hline T'\rightarrow \ast YT' \mid \epsilon & \{\ast,\epsilon\} & \{\ast,$,)\}  \\ \hline Y\rightarrow (Z) \mid id & \{(,id\} & \{\ast,\$,)\} \\ \hline \end{array}$$ So, the correct answer is $(B)$.

Reference:

• http://www.cs.nuim.ie/~jpower/Courses/Previous/parsing/node48.html
• https://sites.tufts.edu/comp181/2013/10/05/first-and-follow-sets/
• https://www.jambe.co.nz/UNI/FirstAndFollowSets.html
• https://drive.google.com/open?id=1UOH5Tbrr5HTPaWyDFtlRz60tq03XfoIO

Answer 2

B is Correct.