Editing LR parser (section)

=== Augmented grammar ===

Before the transitions between the different states are determined, the grammar is augmented with an extra rule
: (0) S → E eof

where S is a new start symbol and E the old start symbol. The parser will use this rule for reduction exactly when it has accepted the whole input string.

For this example, the same grammar as above is augmented thus:
: (0) S → E eof
: (1) E → E * B
: (2) E → E + B
: (3) E → B
: (4) B → 0
: (5) B → 1

It is for this augmented grammar that the item sets and the transitions between them will be determined.