0    5          rule-name-opt ->
   5   13          IDENT
  13   25          attrib-seq-opt ->
  25   14          symbol -> IDENT attrib-seq-opt
  14   28          ARROW
  28   13 ?        IDENT
  13   25          attrib-seq-opt ->
  25   33          symbol -> IDENT attrib-seq-opt
  33   35          symbol-seq -> symbol
  35   13 ?        IDENT
  13   25          attrib-seq-opt ->
  25   38          symbol -> IDENT attrib-seq-opt
  38   35          symbol-seq -> symbol-seq symbol
  35   13 ?        IDENT
  13   25          attrib-seq-opt ->
  25   38          symbol -> IDENT attrib-seq-opt
  38   35          symbol-seq -> symbol-seq symbol
  35   34          symbol-seq-opt -> symbol-seq
  35   34  <       symbol-seq-opt -> symbol-seq
  34    4   !    2 rule <* -> rule-name-opt symbol ARROW symbol-seq-opt >
   4    3          rule-seq -> rule
   3    5          rule-name-opt ->
   5   13          IDENT
  13   25          attrib-seq-opt ->
  25   14          symbol -> IDENT attrib-seq-opt
  14   28          ARROW
  28   34          symbol-seq-opt ->
  34   12   !    0 rule <* -> rule-name-opt symbol ARROW symbol-seq-opt >
  12    3          rule-seq -> rule-seq rule
   3    1          LBRACK
   1   10          slip-spec-opt ->
  10   16          IDENT
  16   30          RBRACK
  30    6          rule-name -> LBRACK slip-spec-opt IDENT RBRACK
   6    5          rule-name-opt -> rule-name
   5   13          IDENT
  13   25          attrib-seq-opt ->
  25   14          symbol -> IDENT attrib-seq-opt
  14   28          ARROW
  28   13 ?        IDENT
  13   25          attrib-seq-opt ->
  25   33          symbol -> IDENT attrib-seq-opt
  33   35          symbol-seq -> symbol
  35   34          symbol-seq-opt -> symbol-seq
  34   12   !    1 rule <* -> rule-name-opt symbol ARROW symbol-seq-opt >
  12    3          rule-seq -> rule-seq rule
   3    2          rule-seq-opt -> rule-seq
   2               start -> rule-seq-opt