Construction of LR Table: Items
20/42
Definition: Let G = (N, T, P, S) be a CFG,
A ® x Î P, x = yz. Then, A ® y·z is an item.
Example: Consider E ® E+T
All items for E ® E+T are:
E ® ·E+T, E ® E·+T, E ® E+·T, E ® E+T·
Gist: Item is a rule of CFG with · in the right side of rule.
Meaning: A ® y·z means that if y appears on the pushdown top and a prefix of the input is eventually reduced to z, then yz (= x) as a handle can be reduced to A according to A ® x.