Question

(a). Compute the FIRST set for the right-hand side of each rule in the following grammar.

<list> → ( <element-list> )
<list> → ( )
<element-list> → <element> <element-list>
<element-list> → <element>
<element> → a
<element> → b
<element> → <list>

(b) Modify the grammar so that it can be parsed using an LL parser. Keep the modified
grammar as simple and as close to the original grammar as possible.

Answer 1

<list>-> ( $\epsilon$ ,a,b)

<list>-> ( $\epsilon$ )

<element-list>->( $\epsilon$ ,a,b)

<element-list>->(a.b)

<element>->first(a)=a

<element>->first(b)=b

$\epsilon$	<list> → ( )
a	<element> → a
b	<element> → b

If the grammer does not contain multiple entry, then it should be LL parser.