GATE Computer Science (CS) 2019 Solved Papers

Consider the following grammar and the semantic actions to support the inherited type declaration attributes. Let ${\mathit{X}}_1,{\mathit{X}}_2,{\mathit{X}}_3$ ${\mathit{X}}_4,{\mathit{X}}_5$, and ${\mathit{X}}_6$ be the placeholders for the non-terminals $\mathit{D},\mathit{T},\mathit{L}$ or $\mathit{L}1$ in the following table:

Production rule	Semantic action
$\mathit{D}\to \mathit{T}\mathit{L}$	${\mathit{X}}_1.$ type $={\mathit{X}}_2$.type
$\mathit{T}\to$ int	T.type $=$ int
T.type $=$ int	t.type $=$ float
$\mathit{L}\to {\mathit{L}}_1$, id	X3.type $=\mathit{X}4$.type and Type (id.type, ${\mathit{X}}_5$.type)
$\mathit{L}\to \mathit{i}\mathit{d}$	add Type(id.entry, ${\mathit{X}}_6$.type)

Which one of the following are the appropriate choices for ${\mathit{X}}_1,{\mathit{X}}_2,{\mathit{X}}_3$ and ${\mathit{X}}_4$ ?