Evaluation of Expressions: Example 10/16
Example for a + b, where a.value = 10, b.value = 20
F2 
{R2.i := F2.s}
R2
{T2.s := R2.s}
{Q2.i := Q1.i + T2.s}
Q2
{Q1.s := Q2.s}
{E.s := Q1.s}
$
Parser pushdown:
Q1.i = 10
Semantic pushdown:
Input: i2 $
Rule: F2 ® i2 {F2.s := i.value}
37/69
E
10
+
20
T1
Q1
F2
R2
F1
R1
i1
e
Illustration:
T2
Q2
+