L-attributed or S-attributed, inherited or synthesized?

Question

How to solve this question?

Attributes calculated from children are synthesized, while attributes calculated from parents and/or siblings is inherited. And S-attributed are purely synthesized, while L-attributed are synthesized+inherited, is this right?

Comments

how could it be none ??? i dont know to the extent i know its option c

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I missed that point (inherited attributes are to be derived from its left sibling)

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thats the requirement for L-attirbuted grammar. Otherwise inheritance can be even right.

Answer 1

Answer is D.

In S-attribute grammar we can have only synthesized attributes.

In L-attribute grammar we can have both synthesized as well as inherited attributes, but the inherited attributes must come from left side (not from right side) only. Here, $R_i = T_i, F_i = R_i, E_i = F_i$ violate this making this not L-attributed grammar,

Comments

Oh, so it means, F should be calculated from E only, and R should be calculated from E or F, and so on... Thanks..

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yes. Or from S which is the parent.

Answer 2

Answer is D.