Exercise 3.

Consider the following syntax-directed definition for the point size and height of boxes containing mathematical formulas.

Production	Semantic Rule
S $\longmapsto$ B	B.ps := 10
	S.ht := B.ht
B $\longmapsto$ B1 B2	B1.ps := B.ps
	B2.ps := B.ps
	B.ht := max( B1.ht, B2.ht)
B $\longmapsto$ B1 $\bf sub$ B2	B1.ps := B.ps
	B2.ps := shrink(B.ps)
	B.ht := disp( B1.ht, B2.ht)
B $\longmapsto$ $\bf text$	B.ht := $\bf text$.h×B.ps

Write a translation scheme for this syntax-directed definition.

Answer 3