Rules useless in parser due to conflicts

    5 B: a


State 3 conflicts: 1 shift/reduce


Grammar

    0 $accept: S $end

    1 S: e B b A
    2  | e A

    3 A: a
    4  | %empty

    5 B: a
    6  | a D

    7 D: b


Terminals, with rules where they appear

    $end (0) 0
    error (256)
    e (258) 1 2
    b (259) 1 7
    a (260) 3 5 6


Nonterminals, with rules where they appear

    $accept (6)
        on left: 0
    S (7)
        on left: 1 2
        on right: 0
    A (8)
        on left: 3 4
        on right: 1 2
    B (9)
        on left: 5 6
        on right: 1
    D (10)
        on left: 7
        on right: 6


State 0

    0 $accept: • S $end
    1 S: • e B b A
    2  | • e A

    e  shift, and go to state 1

    S  go to state 2


State 1

    1 S: e • B b A
    2  | e • A
    3 A: • a
    4  | • %empty  [$end]
    5 B: • a
    6  | • a D

    a  shift, and go to state 3

    $default  reduce using rule 4 (A)

    A  go to state 4
    B  go to state 5


State 2

    0 $accept: S • $end

    $end  shift, and go to state 6


State 3

    3 A: a •  [$end]
    5 B: a •  [b]
    6  | a • D
    7 D: • b

    b  shift, and go to state 7

    b         [reduce using rule 5 (B)]
    $default  reduce using rule 3 (A)

    D  go to state 8

    shift/reduce conflict on token b:
        5 B: a •
        7 D: • b
      First example: a • b b A
      Shift derivation
        S
        ↳ B         b A
          ↳ a D
              ↳ • b
      Second example: a • b
      Reduce derivation
        S
        ↳ B     b A
          ↳ a •   ↳ ε



State 4

    2 S: e A •

    $default  reduce using rule 2 (S)


State 5

    1 S: e B • b A

    b  shift, and go to state 9


State 6

    0 $accept: S $end •

    $default  accept


State 7

    7 D: b •

    $default  reduce using rule 7 (D)


State 8

    6 B: a D •

    $default  reduce using rule 6 (B)


State 9

    1 S: e B b • A
    3 A: • a
    4  | • %empty  [$end]

    a  shift, and go to state 10

    $default  reduce using rule 4 (A)

    A  go to state 11


State 10

    3 A: a •

    $default  reduce using rule 3 (A)


State 11

    1 S: e B b A •

    $default  reduce using rule 1 (S)