Use the following grammar to answer the questions below

Syntax rule: $($:$E$:$)($:$E$:$)[1]+($:$T$:$)$

Semantic rule: $($:$E$:$).$val $=E[1].$val $+$ T$.$val

Syntax rule: $($:$E$:$)($:$T$:$)$

Semantic rule: $($:$E$:$)$ val $=($:$T$:$).$val

Syntax rule: $($:$T$:$)($:$T$:$)[1{]}^{**}($:$F$:$)$

Semantic rule: $($:$T$:$).$ val $=($:$T$:$)[1{]}^{**}($:$F$:$).$ val

Syntax rule: $($:$T$:$)($:$F$:$)$

Semantic rule: $($:$T$:$).$val $=($:$F$:$).$val

Syntax rule: $($:$F$:$)2|3|4|5$

Semantic rule: $($:$F$:$).$ val $-$ lookup$(($:$F$:$))$

$($a$)$ Draw a fully attributed parse tree for the sentence $2+3^{{?}^{{?}^{?}}}5.$ You can upload a

picture. Indicate whether each attribute is intrinsic, synthesized or inherited.

$($b$)$ According to the attribute grammar, is this sentence valid? If not, where in the

tree is the invalidity discovered?