semantics are perl5.  version is 0.001_019.  start symbol is S.

S: A, Y. 'rule0'. # Call me the start rule
note: you can also call me Rule 0.

A: . 'rule1'. # Call me Rule 1

A: B, C. 'rule2'. # Call me Rule 2

B: . q{rule3}. # Call me Rule 3

C: . q{rule4}. # Call me Rule 4

C: Y.  q{rule5}. # Call me Rule 5

Y: /Z/. 'rule6'. # Call me Rule 6


